Merge branch 'master' of xbib.org:joerg/graphics

.gitignore

@@ -6,4 +6,4 @@
 /.gradle
 build
 *~
-/*.iml
+*.iml

gradle.properties

@@ -1,16 +1,16 @@
 group = org.xbib.graphics
 name = graphics
-version = 4.0.2
+version = 4.0.3
 
 gradle.wrapper.version = 6.6.1
-pdfbox.version = 2.0.22
-jna.version = 5.7.0
+pdfbox.version = 2.0.23
+jna.version = 5.8.0
 zxing.version = 3.3.1
 reflections.version = 0.9.11
 jfreechart.version = 1.5.1
 batik.version = 1.13
 junit.version = 5.7.1
-junit4.version = 4.13
+junit4.version = 4.13.2
 groovy.version = 2.5.12
 spock.version = 1.3-groovy-2.5
 cglib.version = 3.2.5

gradle/compile/java.gradle

@@ -29,6 +29,7 @@ task sourcesJar(type: Jar, dependsOn: classes) {
 
 task javadocJar(type: Jar, dependsOn: javadoc) {
     classifier 'javadoc'
+    from javadoc.destinationDir
 }
 
 artifacts {

graphics-barcode/src/test/java/org/xbib/graphics/barcode/output/EPSRendererTest.java

@@ -4,6 +4,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 import org.xbib.graphics.barcode.Code93;
 import org.xbib.graphics.barcode.render.BarcodeGraphicsRenderer;
 import org.xbib.graphics.barcode.MaxiCode;
@@ -22,6 +24,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Locale;
 
+@DisabledOnOs(OS.MAC)
 public class EPSRendererTest {
 
     private Locale originalDefaultLocale;

graphics-barcode/src/test/java/org/xbib/graphics/barcode/output/PDFRendererTest.java

@@ -4,6 +4,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 import org.xbib.graphics.barcode.Code93;
 import org.xbib.graphics.barcode.MaxiCode;
 import org.xbib.graphics.barcode.AbstractSymbol;
@@ -22,6 +24,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Locale;
 
+@DisabledOnOs(OS.MAC)
 public class PDFRendererTest {
 
     private Locale originalDefaultLocale;

graphics-barcode/src/test/java/org/xbib/graphics/barcode/output/SVGRendererTest.java

@@ -4,6 +4,8 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.DisabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 import org.xbib.graphics.barcode.Code93;
 import org.xbib.graphics.barcode.MaxiCode;
 import org.xbib.graphics.barcode.AbstractSymbol;
@@ -22,6 +24,7 @@ import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.Locale;
 
+@DisabledOnOs(OS.MAC)
 public class SVGRendererTest {
 
     private Locale originalDefaultLocale;

graphics-graph-gral/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+    testImplementation "org.junit.vintage:junit-vintage-engine:${project.property('junit4.version')}"
+}

graphics-graph-gral/src/main/java/module-info.java

@@ -0,0 +1,3 @@
+module org.xbib.graphics.graphics.graph.gral {
+    requires java.desktop;
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/AbstractDataSource.java

@@ -0,0 +1,323 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Set;
+
+/**
+ * Abstract implementation of the {@code DataSource} interface.
+ * This class provides access to statistical information,
+ * administration and notification of listeners and supports
+ * iteration of data values.
+ */
+@SuppressWarnings("serial")
+public abstract class AbstractDataSource implements DataSource {
+
+	/** Name of the data source. */
+	private String name;
+	/** Number of columns. */
+	private int columnCount;
+	/** Data types that are allowed in the respective columns. */
+	private Class<? extends Comparable<?>>[] types;
+	/** Set of objects that will be notified of changes to the data values. */
+	private transient Set<DataListener> dataListeners;
+	/** Statistical description of the data values. */
+	private transient Statistics statistics;
+
+	/**
+	 * Iterator that returns each row of the DataSource.
+	 */
+	private class DataSourceIterator implements Iterator<Comparable<?>> {
+		/** Index of current column. */
+		private int col;
+		/** Index of current row. */
+		private int row;
+
+		/**
+		 * Initializes a new iterator instance that starts at (0, 0).
+		 */
+		public DataSourceIterator() {
+			col = 0;
+			row = 0;
+		}
+
+	    /**
+	     * Returns {@code true} if the iteration has more elements.
+	     * (In other words, returns {@code true} if {@code next}
+	     * would return an element rather than throwing an exception.)
+	     * @return {@code true} if the iterator has more elements.
+	     */
+		public boolean hasNext() {
+			return (col < getColumnCount()) && (row < getRowCount());
+		}
+
+	    /**
+	     * Returns the next element in the iteration.
+	     * @return the next element in the iteration.
+	     * @exception NoSuchElementException iteration has no more elements.
+	     */
+		public Comparable<?> next() {
+			if (!hasNext()) {
+				throw new NoSuchElementException();
+			}
+			Comparable<?> value = get(col, row);
+			if (++col >= getColumnCount()) {
+				col = 0;
+				++row;
+			}
+			return value;
+		}
+
+	    /**
+	     * Method that theoretically removes a cell from a data source.
+	     * However, this is not supported.
+	     */
+		public void remove() {
+			throw new UnsupportedOperationException();
+		}
+	}
+
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public AbstractDataSource() {
+		this(null, new Class[0]);
+	}
+
+	/**
+	 * Initializes a new instance with the specified name, number of columns, and
+	 * column types.
+	 * @param name name of the DataSource
+	 * @param types type for each column
+	 */
+	@SuppressWarnings("unchecked")
+	public AbstractDataSource(String name, Class<? extends Comparable<?>>... types) {
+		this.name = name;
+		setColumnTypes(types);
+		dataListeners = new LinkedHashSet<>();
+	}
+
+	/**
+	 * Initializes a new instance with the specified number of columns and
+	 * column types.
+	 * @param types type for each column
+	 */
+	@SuppressWarnings("unchecked")
+	public AbstractDataSource(Class<? extends Comparable<?>>... types) {
+		this(null, types);
+	}
+
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public AbstractDataSource(Column<?>... remainingColumns) {
+		Class<? extends Comparable<?>>[] columnTypes = new Class[remainingColumns.length];
+		for (int columnIndex = 0; columnIndex < remainingColumns.length; columnIndex++) {
+			Column<?> column = remainingColumns[columnIndex];
+			columnTypes[columnIndex] = column.getType();
+		}
+		setColumnTypes(columnTypes);
+
+		dataListeners = new LinkedHashSet<>();
+	}
+
+	/**
+	 * Retrieves a object instance that contains various statistical
+	 * information on the current data source.
+	 * @return statistical information
+	 */
+	public Statistics getStatistics() {
+		if (statistics == null) {
+			statistics = new Statistics(this);
+		}
+		return statistics;
+	}
+
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public DataSource getColumnStatistics(String key) {
+		Class<? extends Comparable<?>>[] columnTypes = new Class[getColumnCount()];
+		Arrays.fill(columnTypes, Double.class);
+		DataTable statisticsTable = new DataTable(columnTypes);
+		List<Double> colStatistics = new ArrayList<>(columnTypes.length);
+		for (int colIndex = 0; colIndex < getColumnCount(); colIndex++) {
+			Column<?> col = getColumn(colIndex);
+			colStatistics.add(col.getStatistics(key));
+		}
+		if (!colStatistics.isEmpty()) {
+			statisticsTable.add(colStatistics);
+		}
+		return statisticsTable;
+	}
+
+	@SuppressWarnings("unchecked")
+	public DataSource getRowStatistics(String key) {
+		DataTable statisticsTable = getRowCount() != 0 ? new DataTable(Double.class) : new DataTable();
+		for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
+			Record row = getRecord(rowIndex);
+			statisticsTable.add(new Statistics(row).get(key));
+		}
+		return statisticsTable;
+	}
+
+	/**
+	 * Adds the specified {@code DataListener} to this data source.
+	 * @param dataListener listener to be added.
+	 */
+	public void addDataListener(DataListener dataListener) {
+		dataListeners.add(dataListener);
+	}
+
+	/**
+	 * Removes the specified {@code DataListener} from this data source.
+	 * @param dataListener listener to be removed.
+	 */
+	public void removeDataListener(DataListener dataListener) {
+		dataListeners.remove(dataListener);
+	}
+
+    /**
+     * Returns an iterator over a set of elements of type T.
+     *
+     * @return an Iterator.
+     */
+	public Iterator<Comparable<?>> iterator() {
+		return new DataSourceIterator();
+	}
+
+	/**
+	 * Notifies all registered listeners that data values have been added.
+	 * @param events Event objects describing all values that have been added.
+	 */
+	protected void notifyDataAdded(DataChangeEvent... events) {
+		List<DataListener> listeners = new LinkedList<>(dataListeners);
+		for (DataListener dataListener : listeners) {
+			dataListener.dataAdded(this, events);
+		}
+	}
+
+	/**
+	 * Notifies all registered listeners that data values have been removed.
+	 * @param events Event objects describing all values that have been removed.
+	 */
+	protected void notifyDataRemoved(DataChangeEvent... events) {
+		List<DataListener> listeners = new LinkedList<>(dataListeners);
+		for (DataListener dataListener : listeners) {
+			dataListener.dataRemoved(this, events);
+		}
+	}
+
+	/**
+	 * Notifies all registered listeners that data values have changed.
+	 * @param events Event objects describing all values that have changed.
+	 */
+	protected void notifyDataUpdated(DataChangeEvent... events) {
+		List<DataListener> listeners = new LinkedList<>(dataListeners);
+		for (DataListener dataListener : listeners) {
+			dataListener.dataUpdated(this, events);
+		}
+	}
+
+	/**
+	 * Returns the column with the specified index.
+	 * @param col index of the column to return
+	 * @return the specified column of the data source
+	 */
+	@SuppressWarnings({"unchecked","rawtypes"})
+	@Override
+	public Column<?> getColumn(int col) {
+		Class<? extends Comparable<?>> columnType = getColumnTypes()[col];
+		List<Comparable<?>> columnData = new LinkedList<>();
+		for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
+			Record record = getRecord(rowIndex);
+			columnData.add(record.get(col));
+		}
+		return new Column(columnType, columnData.toArray(new Comparable[0]));
+	}
+
+	@Override
+	public String getName() {
+		return name;
+	}
+
+	@Override
+	public Record getRecord(int row) {
+		return new Record(getRow(row).toArray(null));
+	}
+
+	// Allows DataTable to reuse the name property
+	protected void setName(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * Returns the number of columns of the data source.
+	 * @return number of columns in the data source.
+	 */
+	public int getColumnCount() {
+		return columnCount;
+	}
+
+
+	/**
+	 * Returns the data types of all columns.
+	 * @return The data types of all column in the data source
+	 */
+	public Class<? extends Comparable<?>>[] getColumnTypes() {
+		return Arrays.copyOf(this.types, this.types.length);
+	}
+
+	/**
+	 * Returns whether the column at the specified index contains numbers.
+	 * @param columnIndex Index of the column to test.
+	 * @return {@code true} if the column is numeric, otherwise {@code false}.
+	 */
+	public boolean isColumnNumeric(int columnIndex) {
+		if (columnIndex < 0 || columnIndex >= types.length) {
+			return false;
+		}
+		Class<?> columnType = types[columnIndex];
+		return Number.class.isAssignableFrom(columnType);
+	}
+
+	/**
+	 * Sets the data types of all columns. This also changes the number of
+	 * columns.
+	 * @param types Data types.
+	 */
+	@SuppressWarnings("unchecked")
+	protected void setColumnTypes(Class<? extends Comparable<?>>... types) {
+		this.types = Arrays.copyOf(types, types.length);
+		columnCount = types.length;
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param row Index of the row to return
+	 * @return the Specified row of the data source
+	 */
+	public Row getRow(int row) {
+		return new Row(this, row);
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Handle transient fields
+		dataListeners = new HashSet<>();
+		// Statistics can be omitted. It's created using a lazy getter.
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/Column.java

@@ -0,0 +1,81 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * <p>Class for accessing a specific column of a data source. The data of the
+ * column can be accessed using the {@code get(int)} method.</p>
+ *
+ * <p>Example for accessing value at column 2, row 3 of a data source:</p>
+ * <pre>
+ * Column col = new Column(dataSource, 2);
+ * Number v = col.get(3);
+ * </pre>
+ *
+ * @see DataSource
+ */
+public class Column<T extends Comparable<T>> implements Iterable<T> {
+
+	private final Class<T> dataType;
+	private final List<T> data;
+
+	@SuppressWarnings("unchecked")
+	public Column(Class<T> dataType, T... data) {
+		this(dataType, Arrays.asList(data));
+	}
+
+	public Column(Class<T> dataType, Iterable<T> data) {
+		this.dataType = dataType;
+		this.data = new ArrayList<>();
+		for (T item : data) {
+			this.data.add(item);
+		}
+	}
+
+	public T get(int row) {
+		return row >= data.size() ? null : data.get(row);
+	}
+
+	public int size() {
+		return data.size();
+	}
+
+	/**
+	 * Returns whether this column only contains numbers.
+	 * @return {@code true} if this column is numeric, otherwise {@code false}.
+	 */
+	public boolean isNumeric() {
+		return Number.class.isAssignableFrom(getType());
+	}
+
+	public Class<? extends Comparable<?>> getType() {
+		return dataType;
+	}
+
+	public double getStatistics(String key) {
+		return new Statistics(data).get(key);
+	}
+
+	@Override
+	public int hashCode() {
+		return dataType.hashCode() ^ data.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof Column)) {
+			return false;
+		}
+		Column<?> column = (Column<?>) obj;
+		return getType().equals(column.getType()) && data.equals(column.data);
+	}
+
+	@Override
+	public Iterator<T> iterator() {
+		return data.iterator();
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataAccessor.java

@@ -0,0 +1,151 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import java.text.MessageFormat;
+import java.util.Iterator;
+import java.util.Locale;
+
+/**
+ * Abstract base for reading substructures of a data source, i.e. columns or
+ * rows. {@code DataAccessor}s are iterable and provide utility methods
+ * for statistics and array conversion.
+ * @see DataSource
+ */
+public abstract class DataAccessor implements Iterable<Comparable<?>> {
+
+	/** Data source that provides the values that should be accessed. */
+	private final DataSource source;
+	/** Index of current column or row. */
+	private final int index;
+
+	/**
+	 * Initializes a new instance with the specified data source and an access
+	 * index.
+	 * @param source Data source.
+	 * @param index Column index.
+	 */
+	public DataAccessor(DataSource source, int index) {
+		this.source = source;
+		this.index = index;
+	}
+
+	/**
+	 * Returns the data source containing this column.
+	 * @return Data source containing this column.
+	 */
+	public DataSource getSource() {
+		return source;
+	}
+
+	/**
+	 * Returns the index to access the data source.
+	 * @return Data index.
+	 */
+	public int getIndex() {
+		return index;
+	}
+
+	/**
+	 * Returns the value of the data source for the specified index.
+	 * @param index Index.
+	 * @return Value of the accessed cell.
+	 */
+	public abstract Comparable<?> get(int index);
+
+	/**
+	 * Returns the number of elements in this column.
+	 * @return Number of elements
+	 */
+	public abstract int size();
+
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof DataAccessor)) {
+			return false;
+		}
+		DataAccessor accessor = (DataAccessor) obj;
+		int size = size();
+		if (accessor.size() != size) {
+			return false;
+		}
+		for (int i = 0; i < size; i++) {
+			Comparable<?> foreignValue = accessor.get(i);
+			Comparable<?> thisValue = get(i);
+			if (foreignValue == null) {
+				if (thisValue != null) {
+					return false;
+				}
+				continue;
+			}
+			if (!foreignValue.equals(thisValue)) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	@Override
+	public int hashCode() {
+		return source.hashCode() ^ index;
+	}
+
+	@Override
+	public String toString() {
+		return String.format(Locale.US,
+			"%s[source=%s,index=%d]", //$NON-NLS-1$
+			getClass().getName(), getSource(), getIndex());
+	}
+
+	/**
+	 * Converts the data column to an array.
+	 * @param data Optional array as data sink.
+	 *             If array is {@code null} a new array will be created.
+	 * @return Array with row data;
+	 */
+	public Comparable<?>[] toArray(Comparable<?>[] data) {
+		if (data == null) {
+			data = new Comparable<?>[size()];
+		}
+		if (data.length != size()) {
+			throw new IllegalArgumentException(MessageFormat.format(
+				"Array of size {0,number,integer} does not match {1,number,integer} elements.", //$NON-NLS-1$
+				data.length, size()));
+		}
+		for (int i = 0; i < data.length; i++) {
+			data[i] = get(i);
+		}
+		return data;
+	}
+
+	/**
+	 * Returns the specified statistical information for this data.
+	 * @param key Requested Statistical information.
+	 * @return Calculated value.
+	 */
+	public double getStatistics(String key) {
+		Statistics statistics = new Statistics(this);
+		return statistics.get(key);
+	}
+
+    /**
+     * Returns an iterator over the elements of this object.
+     * @return an iterator.
+     */
+	public Iterator<Comparable<?>> iterator() {
+		return new Iterator<Comparable<?>>() {
+			private int i;
+
+			public boolean hasNext() {
+				return i < size();
+			}
+
+			public Comparable<?> next() {
+				return get(i++);
+			}
+
+			public void remove() {
+				throw new UnsupportedOperationException();
+			}
+		};
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataChangeEvent.java

@@ -0,0 +1,73 @@
+package org.xbib.graphics.graph.gral.data;
+
+import java.util.EventObject;
+
+/**
+ * Class that stores information on a change of a specific data value in a
+ * data source.
+ * @see DataListener
+ * @see DataSource
+ */
+@SuppressWarnings("serial")
+public class DataChangeEvent extends EventObject {
+
+	/** Column of the value that has changed. */
+	private final int col;
+	/** Row of the value that has changed. */
+	private final int row;
+	/** Value before changes have been applied. */
+	private final Comparable<?> valOld;
+	/** Changed value. */
+	private final Comparable<?> valNew;
+
+	/**
+	 * Initializes a new event with data source, position of the data value,
+	 * and the values.
+	 * @param <T> Data type of the cell that has changed.
+	 * @param source Data source.
+	 * @param col Columns of the value.
+	 * @param row Row of the value.
+	 * @param valOld Old value.
+	 * @param valNew New value.
+	 */
+	public <T> DataChangeEvent(DataSource source, int col, int row,
+			Comparable<T> valOld, Comparable<T> valNew) {
+		super(source);
+		this.col = col;
+		this.row = row;
+		this.valOld = valOld;
+		this.valNew = valNew;
+	}
+
+	/**
+	 * Returns the column index of the value that was changed.
+	 * @return Column index of the changed value.
+	 */
+	public int getCol() {
+		return col;
+	}
+
+	/**
+	 * Returns the row index of the value that was changed.
+	 * @return Row index of the changed value.
+	 */
+	public int getRow() {
+		return row;
+	}
+
+	/**
+	 * Returns the old value before it has changed.
+	 * @return Value before the change.
+	 */
+	public Comparable<?> getOld() {
+		return valOld;
+	}
+
+	/**
+	 * Returns the new value after the change has been applied.
+	 * @return Value after the change.
+	 */
+	public Comparable<?> getNew() {
+		return valNew;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataListener.java

@@ -0,0 +1,37 @@
+package org.xbib.graphics.graph.gral.data;
+
+/**
+ * Interface that can be implemented to listen for changes in data sources.
+ * @see DataSource
+ */
+public interface DataListener {
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	void dataAdded(DataSource source, DataChangeEvent... events);
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	void dataUpdated(DataSource source, DataChangeEvent... events);
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	void dataRemoved(DataSource source, DataChangeEvent... events);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataSeries.java

@@ -0,0 +1,152 @@
+package org.xbib.graphics.graph.gral.data;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Class that represents a view on several columns of a {@code DataSource}.
+ * @see DataSource
+ */
+public class DataSeries extends AbstractDataSource implements DataListener {
+
+	/** Data source that provides the columns for this data series. */
+	private final DataSource data;
+
+	/** Columns that should be mapped to the series. */
+	private final List<Integer> cols;
+
+	/**
+	 * Constructor without name. The first column will be column
+	 * {@code 0}, the second column {@code 1} and so on,
+	 * whereas the value of the specified columns is the column number
+	 * in the data source.
+	 * @param data Data source
+	 * @param cols Column numbers
+	 */
+	public DataSeries(DataSource data, int... cols) {
+		this(null, data, cols);
+	}
+
+	/**
+	 * Constructor that initializes a named data series. The first column will
+	 * be column {@code 0}, the second column {@code 1} and so on,
+	 * whereas the value of the specified columns is the column number in the
+	 * data source.
+	 * @param name Descriptive name
+	 * @param data Data source
+	 * @param cols Column numbers
+	 */
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public DataSeries(String name, DataSource data, int... cols) {
+		super(name);
+		this.data = data;
+		this.cols = new ArrayList<>();
+		this.data.addDataListener(this);
+
+		Class<? extends Comparable<?>>[] typesOrig = data.getColumnTypes();
+		Class<? extends Comparable<?>>[] types;
+
+		if (cols.length > 0) {
+			types = new Class[cols.length];
+			int t = 0;
+			for (int colIndex : cols) {
+				this.cols.add(colIndex);
+				types[t++] = typesOrig[colIndex];
+			}
+		} else {
+			for (int colIndex = 0; colIndex < data.getColumnCount(); colIndex++) {
+				this.cols.add(colIndex);
+			}
+			types = typesOrig;
+		}
+
+		setColumnTypes(types);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		try {
+			int dataCol = cols.get(col);
+			return data.get(dataCol, row);
+		} catch (IndexOutOfBoundsException e) {
+			return null;
+		}
+	}
+
+	@Override
+	public int getColumnCount() {
+		return cols.size();
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return data.getRowCount();
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		notifyDataAdded(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		notifyDataUpdated(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		notifyDataRemoved(events);
+	}
+
+	@Override
+	public String toString() {
+		return getName();
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Restore listeners
+		data.addDataListener(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataSource.java

@@ -0,0 +1,90 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+
+/**
+ * Interface for an immutable access to tabular data.
+ *
+ * @see MutableDataSource
+ */
+public interface DataSource extends Iterable<Comparable<?>> {
+	/**
+	 * Returns the column with the specified index.
+	 * @param col index of the column to return
+	 * @return the specified column of the data source
+	 */
+	// It is not possible to use this function with a generic type parameter,
+	// due to broken type inference prior to Java 8.
+	Column<?> getColumn(int col);
+
+	/**
+	 * Returns the data types of all columns.
+	 * @return The data types of all column in the data source
+	 */
+	Class<? extends Comparable<?>>[] getColumnTypes();
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param row index of the row to return
+	 * @return the specified row of the data source
+	 */
+	Row getRow(int row);
+
+	/**
+	 * Returns the value with the specified row and column index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	Comparable<?> get(int col, int row);
+
+	/**
+	 * Retrieves a object instance that contains various statistical
+	 * information on the current data source.
+	 * @return statistical information
+	 */
+	Statistics getStatistics();
+
+	DataSource getColumnStatistics(String key);
+
+	DataSource getRowStatistics(String key);
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	int getRowCount();
+
+	/**
+	 * Returns the name of this series.
+	 * @return a name string
+	 */
+	String getName();
+
+	/**
+	 * Returns the number of columns of the data source.
+	 * @return number of columns in the data source.
+	 */
+	int getColumnCount();
+
+	/**
+	 * Returns whether the column at the specified index contains numbers.
+	 * @param columnIndex Index of the column to test.
+	 * @return {@code true} if the column is numeric, otherwise {@code false}.
+	 */
+	boolean isColumnNumeric(int columnIndex);
+
+	/**
+	 * Adds the specified {@code DataListener} to this data source.
+	 * @param dataListener listener to be added.
+	 */
+	void addDataListener(DataListener dataListener);
+
+	/**
+	 * Removes the specified {@code DataListener} from this data source.
+	 * @param dataListener listener to be removed.
+	 */
+	void removeDataListener(DataListener dataListener);
+
+	Record getRecord(int row);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DataTable.java

@@ -0,0 +1,334 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.comparators.DataComparator;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * An in-memory, random access implementation of a mutable data source using
+ * arrays to store its values.
+ *
+ * @see DataSource
+ * @see MutableDataSource
+ */
+public class DataTable extends AbstractDataSource implements MutableDataSource {
+
+	/** All values stored as rows of column arrays. */
+	private final List<Record> rows;
+
+	/**
+	 * Comparator class for comparing two records using a
+	 * specified set of {@code DataComparator}s.
+	 */
+	private final class RecordComparator implements Comparator<Record> {
+		/** Rules to use for sorting. */
+		private final DataComparator[] comparators;
+
+		/**
+		 * Initializes a new instance with a specified set of
+		 * {@code DataComparator}s.
+		 * @param comparators Set of {@code DataComparator}s to use as rules.
+		 */
+		public RecordComparator(DataComparator[] comparators) {
+			this.comparators = comparators;
+		}
+
+		/**
+		 * Compares two records using the rules defined by the
+		 * {@code DataComparator}s of this instance.
+		 * @param record1 First record to compare.
+		 * @param record2 Second record to compare.
+	     * @return A negative number if first argument is less than the second,
+	     *         zero if first argument is equal to the second,
+	     *         or a positive integer as the greater than the second.
+		 */
+		public int compare(Record record1, Record record2) {
+			for (DataComparator comparator : comparators) {
+				int result = comparator.compare(record1, record2);
+				if (result != 0) {
+					return result;
+				}
+			}
+			return 0;
+		}
+	}
+
+	public DataTable() {
+		rows = new ArrayList<>();
+	}
+
+	/**
+	 * Initializes a new instance with the specified number of columns and
+	 * column types.
+	 * @param types Type for each column
+	 */
+	@SuppressWarnings("unchecked")
+	public DataTable(Class<? extends Comparable<?>>... types) {
+		super(types);
+		rows = new ArrayList<>();
+	}
+
+	/**
+	 * Initializes a new instance with the specified number of columns and
+	 * a single column type.
+	 * @param cols Number of columns
+	 * @param type Data type for all columns
+	 */
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public DataTable(int cols, Class<? extends Comparable<?>> type) {
+		this();
+		Class<? extends Comparable<?>>[] types = new Class[cols];
+		Arrays.fill(types, type);
+		setColumnTypes(types);
+	}
+
+	/**
+	 * Initializes a new instance with the column types, and data of another
+	 * data source.
+	 * @param source Data source to clone.
+	 */
+	public DataTable(DataSource source) {
+		this(source.getColumnTypes());
+		for (int rowIndex = 0; rowIndex < source.getRowCount(); rowIndex++) {
+			add(source.getRecord(rowIndex));
+		}
+	}
+
+	@SuppressWarnings("rawtypes")
+	public DataTable(Column... columns) {
+		super(columns);
+		rows = new ArrayList<>();
+
+		int maxRowCount = 0;
+		for (Column<?> column : columns) {
+			maxRowCount = Math.max(maxRowCount, column.size());
+		}
+
+		for (int rowIndex = 0; rowIndex < maxRowCount; rowIndex++) {
+			List<Comparable<?>> rowData = new ArrayList<>(1 + columns.length);
+			for (Column<?> column : columns) {
+				rowData.add(column.get(rowIndex));
+			}
+			rows.add(new Record(rowData));
+		}
+	}
+
+	/**
+	 * Adds a row with the specified comparable values to the table.
+	 * The values are added in the order they are specified. If the types of
+	 * the table columns and the values do not match, an
+	 * {@code IllegalArgumentException} is thrown.
+	 * @param values values to be added as a row
+	 * @return Index of the row that has been added.
+	 */
+	public int add(Comparable<?>... values) {
+		return add(Arrays.asList(values));
+	}
+
+	/**
+	 * Adds a row with the specified container's elements to the table.
+	 * The values are added in the order they are specified. If the types of
+	 * the table columns and the values do not match, an
+	 * {@code IllegalArgumentException} is thrown.
+	 * @param values values to be added as a row
+	 * @return Index of the row that has been added.
+	 */
+	public int add(List<? extends Comparable<?>> values) {
+		DataChangeEvent[] events;
+		if (values.size() != getColumnCount()) {
+			throw new IllegalArgumentException(MessageFormat.format(
+					"Wrong number of columns! Expected {0,number,integer}, got {1,number,integer}.", //$NON-NLS-1$
+					getColumnCount(), values.size()));
+		}
+
+		// Check row data types
+		Class<? extends Comparable<?>>[] types = getColumnTypes();
+		for (int colIndex = 0; colIndex < values.size(); colIndex++) {
+			Comparable<?> value = values.get(colIndex);
+			if ((value != null)
+					&& !(types[colIndex].isAssignableFrom(value.getClass()))) {
+				throw new IllegalArgumentException(MessageFormat.format(
+						"Wrong column type! Expected {0}, got {1}.", //$NON-NLS-1$
+						types[colIndex], value.getClass()));
+			}
+		}
+
+		// Add data to row
+		Record row = new Record(values);
+		events = new DataChangeEvent[row.size()];
+		for (int columnIndex = 0; columnIndex < row.size(); columnIndex++) {
+			Comparable<?> value = values.get(columnIndex);
+			events[columnIndex] = new DataChangeEvent(this, columnIndex, rows.size(), null, value);
+		}
+
+		int rowIndex;
+		synchronized (rows) {
+			rows.add(row);
+			rowIndex = rows.size();
+		}
+		notifyDataAdded(events);
+		return rowIndex - 1;
+	}
+
+	/**
+	 * Adds the specified row to the table.
+	 * The values are added in the order they are specified. If the types of
+	 * the table columns and the values do not match, an
+	 * {@code IllegalArgumentException} is thrown.
+	 * @param row Row to be added
+	 * @return Index of the row that has been added.
+	 */
+	public int add(Row row) {
+		List<Comparable<?>> values;
+		synchronized (row) {
+			values = new ArrayList<>(row.size());
+			for (Comparable<?> value : row) {
+				values.add(value);
+			}
+		}
+		return add(values);
+	}
+
+	public void add(Record row) {
+		if (row.size() != getColumnCount()) {
+			throw new IllegalArgumentException("Invalid element count in Record to be added. " +
+					"Expected: "+getColumnCount()+", got: "+row.size());
+		}
+		rows.add(row);
+	}
+
+	/**
+	 * Removes a specified row from the table.
+	 * @param row Index of the row to remove
+	 */
+	public void remove(int row) {
+		DataChangeEvent[] events;
+		synchronized (rows) {
+			Row r = new Row(this, row);
+			events = new DataChangeEvent[getColumnCount()];
+			for (int col = 0; col < events.length; col++) {
+				events[col] = new DataChangeEvent(this, col, row, r.get(col), null);
+			}
+			rows.remove(row);
+		}
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Removes the last row from the table.
+	 */
+	public void removeLast() {
+		DataChangeEvent[] events;
+		synchronized (this) {
+			int row = getRowCount() - 1;
+			Row r = new Row(this, row);
+			events = new DataChangeEvent[getColumnCount()];
+			for (int col = 0; col < events.length; col++) {
+				events[col] = new DataChangeEvent(this, col, row, r.get(col), null);
+			}
+			rows.remove(row);
+		}
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Deletes all rows this table contains.
+	 */
+	public void clear() {
+		DataChangeEvent[] events;
+		synchronized (this) {
+			int cols = getColumnCount();
+			int rows = getRowCount();
+			events = new DataChangeEvent[cols*rows];
+			for (int row = 0; row < rows; row++) {
+				for (int col = 0; col < cols; col++) {
+					events[col + row*cols] = new DataChangeEvent(
+						this, col, row, get(col, row), null);
+				}
+			}
+			this.rows.clear();
+		}
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		Record r;
+		synchronized (rows) {
+			if (row >= rows.size()) {
+				return null;
+			}
+			r = rows.get(row);
+		}
+		if (r == null) {
+			return null;
+		}
+		return r.get(col);
+	}
+
+	/**
+	 * Sets the value of a cell specified by its column and row indexes.
+	 * @param <T> Data type of the cell.
+	 * @param col Column of the cell to change.
+	 * @param row Row of the cell to change.
+	 * @param value New value to be set.
+	 * @return Old value that was replaced.
+	 */
+	@SuppressWarnings("unchecked")
+	public <T> Comparable<T> set(int col, int row, Comparable<T> value) {
+		Comparable<T> old;
+		DataChangeEvent event = null;
+		synchronized (this) {
+			old = (Comparable<T>) get(col, row);
+			if (old == null || !old.equals(value)) {
+				Record record = rows.get(row);
+				ArrayList<Comparable<?>> values = new ArrayList<>(record.size());
+				for (Comparable<?> element : record) {
+					values.add(element);
+				}
+				values.set(col, value);
+				Record updatedRecord = new Record(values);
+				rows.set(row, updatedRecord);
+				event = new DataChangeEvent(this, col, row, old, value);
+			}
+		}
+		if (event != null) {
+			notifyDataUpdated(event);
+		}
+		return old;
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return rows.size();
+	}
+
+	/**
+	 * Sorts the table rows with the specified DataComparators.
+	 * The row values are compared in the way the comparators are specified.
+	 * @param comparators comparators used for sorting
+	 */
+	public void sort(final DataComparator... comparators) {
+		synchronized (rows) {
+			RecordComparator comparator = new RecordComparator(comparators);
+			Collections.sort(rows, comparator);
+		}
+	}
+
+	@Override
+	public void setName(String name) {
+		super.setName(name);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/DummyData.java

@@ -0,0 +1,60 @@
+package org.xbib.graphics.graph.gral.data;
+
+import java.util.Arrays;
+
+
+/**
+ * Class that represents a data source containing the same value in each cell.
+ * It can be used for test purposes or for efficiently creating constant data.
+ */
+public class DummyData extends AbstractDataSource {
+
+	/** Value that will be returned for all positions in this data source. */
+	private final Comparable<?> value;
+	/** Number of columns. */
+	private final int cols;
+	/** Number of rows. */
+	private final int rows;
+
+	/**
+	 * Creates a new instance with the specified number of columns
+	 * and rows, which are filled all over with the same specified value.
+	 * @param cols Number of columns.
+	 * @param rows Number of rows.
+	 * @param value Value of the cells.
+	 */
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public DummyData(int cols, int rows, Comparable<?> value) {
+		this.cols = cols;
+		this.rows = rows;
+		this.value = value;
+
+		Class<? extends Comparable<?>>[] types = new Class[cols];
+		Arrays.fill(types, value.getClass());
+		setColumnTypes(types);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		return value;
+	}
+
+	@Override
+	public int getColumnCount() {
+		return cols;
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return rows;
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/EnumeratedData.java

@@ -0,0 +1,151 @@
+package org.xbib.graphics.graph.gral.data;
+
+/**
+ * <p>Class that creates a new data source which adds a leading column
+ * containing the row number.</p>
+ *
+ * <p>Example which creates a two column data source from a one column
+ * histogram:</p>
+ * <pre>
+ * DataSource hist = new Histogram2D(data, Orientation.HORIZONTAL, 10);
+ * DataSource hist2d = new EnumeratedData(hist);
+ * </pre>
+ *
+ * @see DataSource
+ */
+public class EnumeratedData extends AbstractDataSource
+		implements DataListener {
+
+	/** Data source which will be used as base for enumeration. */
+	private final DataSource original;
+	/** Value to start counting from. */
+	private final double offset;
+	/** Width of enumeration steps. */
+	private final double steps;
+
+	/**
+	 * Initializes a new data source based on an original data source which
+	 * will contain an additional column which enumerates all rows. The
+	 * enumeration will start at a specified offset and will have a specified
+	 * step size.
+	 * @param original Original data source.
+	 * @param offset Offset of enumeration
+	 * @param steps Scaling of enumeration
+	 */
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public EnumeratedData(DataSource original, double offset, double steps) {
+		this.original = original;
+		this.offset = offset;
+		this.steps = steps;
+
+		Class<? extends Comparable<?>>[] typesOrig = original.getColumnTypes();
+		Class<? extends Comparable<?>>[] types = new Class[typesOrig.length + 1];
+		System.arraycopy(typesOrig, 0, types, 1, typesOrig.length);
+		types[0] = Double.class;
+		setColumnTypes(types);
+
+		original.addDataListener(this);
+	}
+
+	/**
+	 * Initializes a new data source based on an original data source which
+	 * will contain an additional column which enumerates all rows.
+	 * @param original Original data source.
+	 */
+	public EnumeratedData(DataSource original) {
+		this(original, 0, 1);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		if (col < 1) {
+			return row*steps + offset;
+		}
+		return original.get(col - 1, row);
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return original.getRowCount();
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		notifyDataAdded(takeEvents(events));
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		notifyDataUpdated(takeEvents(events));
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		notifyDataRemoved(takeEvents(events));
+	}
+
+	/**
+	 * Changes the source and the columns of the specified event objects to
+	 * make them look as if they originated from this data source.
+	 * @param events Original events.
+	 * @return Changed events.
+	 */
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	private DataChangeEvent[] takeEvents(DataChangeEvent[] events) {
+		if (events == null || events.length == 0) {
+			return new DataChangeEvent[] {
+				new DataChangeEvent(this, 0, 0, null, null)
+			};
+		}
+		DataChangeEvent[] eventsTx = new DataChangeEvent[events.length + 1];
+		for (int i = 0; i < eventsTx.length; i++) {
+			DataChangeEvent event;
+			int col, row;
+			if (i == 0) {
+				// Insert an event for the generated column
+				event = events[0];
+				col = 0;
+				row = event.getRow();
+			} else {
+				// Process the columns of the original source
+				event = events[i - 1];
+				col = event.getCol() + 1;
+				row = event.getRow();
+			}
+			Comparable valOld = event.getOld();
+			Comparable valNew = event.getNew();
+			eventsTx[i] = new DataChangeEvent(
+				this, col, row, valOld, valNew);
+		}
+		return eventsTx;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/MutableDataSource.java

@@ -0,0 +1,82 @@
+package org.xbib.graphics.graph.gral.data;
+
+import org.xbib.graphics.graph.gral.data.comparators.DataComparator;
+import java.util.List;
+
+/**
+ * <p>Interface for write access to tabular data. The access includes adding,
+ * modifying, and deleting of the data.</p>
+ * <p>All data can be sorted row-wise with the method
+ * {@code sort(DataComparator...)}. For example, this way column 1 could be
+ * sorted ascending and column 3 descending.
+ *
+ * @see DataSource
+ */
+public interface MutableDataSource extends DataSource {
+	/**
+	 * Adds a row with the specified comparable values. The values are added in
+	 * the order they are specified. If the types of the data sink columns and
+	 * the values do not match, an {@code IllegalArgumentException} is thrown.
+	 * @param values values to be added as a row.
+	 * @return Index of the row that has been added.
+	 */
+	int add(Comparable<?>... values);
+
+	/**
+	 * Adds a row with the specified container's elements to the data sink. The
+	 * values are added in the order they are specified. If the types of the
+	 * data sink columns and the values do not match, an
+	 * {@code IllegalArgumentException} is thrown.
+	 * @param values values to be added as a row.
+	 * @return Index of the row that has been added.
+	 */
+	int add(List<? extends Comparable<?>> values);
+
+	/**
+	 * Adds the specified row to the data sink. The values are added in the
+	 * order they are specified. If the types of the data sink columns and the
+	 * values do not match, an {@code IllegalArgumentException} is thrown.
+	 * @param row Row to be added.
+	 * @return Index of the row that has been added.
+	 */
+	int add(Row row);
+
+	/**
+	 * Removes a specified row from the data sink.
+	 * @param row Index of the row to remove.
+	 */
+	void remove(int row);
+
+	/**
+	 * Removes the last row from the data sink.
+	 */
+	void removeLast();
+
+	/**
+	 * Deletes all rows this data sink contains.
+	 */
+	void clear();
+
+	/**
+	 * Sets the value of a cell specified by its column and row indexes.
+	 * @param <T> Data type of the cell.
+	 * @param col Column of the cell to change.
+	 * @param row Row of the cell to change.
+	 * @param value New value to be set.
+	 * @return Old value that was replaced.
+	 */
+	<T> Comparable<T> set(int col, int row, Comparable<T> value);
+
+	/**
+	 * Sorts the data sink rows with the specified sorting rules. The row
+	 * values are compared in the way the comparators are specified.
+	 * @param comparators Comparators used for sorting.
+	 */
+	void sort(final DataComparator... comparators);
+
+	/**
+	 * Sets the name of this series.
+	 * @param name name to be set
+	 */
+	void setName(String name);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/Record.java

@@ -0,0 +1,82 @@
+package org.xbib.graphics.graph.gral.data;
+
+import static java.util.Arrays.copyOf;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+
+public class Record implements Iterable<Comparable<?>> {
+
+	private final Comparable<?>[] values;
+
+	@SuppressWarnings("rawtypes")
+	public Record(List<? extends Comparable<?>> values) {
+		this.values = values.toArray(new Comparable[0]);
+	}
+
+	public Record(Comparable<?>... values) {
+		this.values = copyOf(values, values.length);
+	}
+
+	@SuppressWarnings("unchecked")
+	public <T extends Comparable<?>> T get(int index) {
+		return (T) values[index];
+	}
+
+	public int size() {
+		return values.length;
+	}
+
+	@Override
+	public Iterator<Comparable<?>> iterator() {
+		// More readable version using Arrays.asList is prevented by broken Generics system
+		List<Comparable<?>> list = new ArrayList<>(values.length);
+		Collections.addAll(list, values);
+		return list.iterator();
+	}
+
+	public boolean isNumeric(int index) {
+		return values[index] instanceof Number;
+	}
+
+
+	public Record insert(Comparable<?> value, int position) {
+		List<Comparable<?>> recordCopyAsList = new ArrayList<>(values.length + 1);
+		Collections.addAll(recordCopyAsList, values);
+		recordCopyAsList.add(position, value);
+		return new Record(recordCopyAsList);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof Record)) {
+			return false;
+		}
+		Record record = (Record) obj;
+		return size() == record.size() && Arrays.equals(this.values, record.values);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hashCode(values);
+	}
+
+	@Override
+	public String toString() {
+		StringBuilder representation = new StringBuilder("(");
+		for (int elementIndex = 0; elementIndex < values.length; elementIndex++) {
+			Comparable<?> element = values[elementIndex];
+			representation.append(element);
+			if (elementIndex != values.length - 1) {
+				representation.append(", ");
+			}
+		}
+		representation.append(")");
+		return representation.toString();
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/Row.java

@@ -0,0 +1,71 @@
+/*
+ * GRAL: GRAphing Library for Java(R)
+ *
+ * (C) Copyright 2009-2019 Erich Seifert <dev[at]erichseifert.de>,
+ * Michael Seifert <mseifert[at]error-reports.org>
+ *
+ * This file is part of GRAL.
+ *
+ * GRAL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRAL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with GRAL.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.xbib.graphics.graph.gral.data;
+
+/**
+ * <p>Class for easily accessing a row of a data source.</p>
+ *
+ * <p>Example:</p>
+ * <pre>
+ * Row row = new Row(data, 2);
+ * Number value = row.get(3);
+ * </pre>
+ *
+ * @see DataSource
+ */
+public class Row extends DataAccessor {
+	/** Version id for serialization. */
+	private static final long serialVersionUID = 2725146484866525573L;
+
+	/**
+	 * Initializes a new instances with the specified data source and
+	 * row index.
+	 * @param source Data source.
+	 * @param row Row index.
+	 */
+	public Row(DataSource source, int row) {
+		super(source, row);
+	}
+
+	@Override
+	public Comparable<?> get(int col) {
+		DataSource source = getSource();
+		if (source == null) {
+			return null;
+		}
+		return source.get(col, getIndex());
+	}
+
+	@Override
+	public int size() {
+		return getSource().getColumnCount();
+	}
+
+	/**
+	 * Returns whether the column at the specified index contains numbers.
+	 * @param columnIndex Index of the column to test.
+	 * @return {@code true} if the column is numeric, otherwise {@code false}.
+	 */
+	public boolean isColumnNumeric(int columnIndex) {
+		return getSource().isColumnNumeric(columnIndex);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/RowSubset.java

@@ -0,0 +1,170 @@
+package org.xbib.graphics.graph.gral.data;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * <p>Abstract class that represents a view on several rows of a data source.
+ * Implementations must implement the method {@code accept(Row)} which
+ * decides whether a specific row should be contained in this filtered data
+ * source.</p>
+ *
+ * <p>Example that keeps only every second row:</p>
+ * <pre>
+ * DataSource filtered = new RowSubset() {
+ *     public boolean accept(Row row) {
+ *         return row.getIndex()%2 == 0;
+ *     }
+ * };
+ * </pre>
+ */
+public abstract class RowSubset extends AbstractDataSource
+		implements DataListener {
+
+	/** Original data source. */
+	private final DataSource original;
+	/** List of row indexes that are stored in this filtered data source. */
+	private transient List<Integer> accepted;
+
+	/**
+	 * Creates a new instance with the specified data source.
+	 * @param original DataSource to be filtered.
+	 */
+	@SuppressWarnings("unchecked")
+	public RowSubset(DataSource original) {
+		accepted = new ArrayList<>();
+		this.original = original;
+		this.original.addDataListener(this);
+		dataUpdated(this.original);
+	}
+
+	@Override
+	public Row getRow(int row) {
+		int rowOrig = accepted.get(row);
+		return original.getRow(rowOrig);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		int rowOrig = accepted.get(row);
+		return original.get(col, rowOrig);
+	}
+
+	@Override
+	public int getColumnCount() {
+		return original.getColumnCount();
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return accepted.size();
+	}
+
+	@Override
+	public Class<? extends Comparable<?>>[] getColumnTypes() {
+		return original.getColumnTypes();
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataAdded(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataUpdated(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been added, updated, or removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been changed.
+	 */
+	private void dataChanged(DataSource source, DataChangeEvent... events) {
+		update();
+	}
+
+	/**
+	 * Updates the list of accepted rows.
+	 */
+	private void update() {
+		accepted.clear();
+		for (int rowIndex = 0; rowIndex < original.getRowCount(); rowIndex++) {
+			Row row = original.getRow(rowIndex);
+			if (accept(row)) {
+				accepted.add(rowIndex);
+			}
+		}
+	}
+
+	/**
+	 * Tests whether the specified row is accepted by this DataSubset or not.
+	 * @param row Row to be tested.
+	 * @return True if the row should be kept.
+	 */
+	public abstract boolean accept(Row row);
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Handle transient fields
+		accepted = new ArrayList<>();
+
+		// Update caches
+		dataUpdated(original);
+
+		// Restore listeners
+		original.addDataListener(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/comparators/Ascending.java

@@ -0,0 +1,52 @@
+package org.xbib.graphics.graph.gral.data.comparators;
+
+import  org.xbib.graphics.graph.gral.data.Record;
+
+/**
+ * Class that represents a {@code DataComparator} for comparing two records
+ * at a defined index for ascending order.
+ */
+public class Ascending extends DataComparator {
+
+	/**
+	 * Creates a new Ascending object for sorting according to the specified
+	 * column.
+	 * @param col Column index to be compared.
+	 */
+	public Ascending(int col) {
+		super(col);
+	}
+
+	/**
+	 * <p>Compares the values of two records at the specified column for order and
+	 * returns a corresponding integer:</p>
+	 * <ul>
+	 *   <li>a negative value means {@code record1} is smaller than {@code record2}</li>
+	 *   <li>0 means {@code record1} is equal to {@code record2}</li>
+	 *   <li>a positive value means {@code record1} is larger than {@code record2}</li>
+	 * </ul>
+	 * @param record1 First record
+	 * @param record2 Second record
+	 * @return An integer number describing the order:
+	 *         a negative value if {@code record1} is smaller than {@code record2},
+	 *         0 if {@code record1} is equal to {@code record2},
+	 *         a positive value if {@code record1} is larger than {@code record2},
+	 */
+	@SuppressWarnings("unchecked")
+	public int compare(Record record1, Record record2) {
+		Comparable<Object> value1 = record1.get(getColumn());
+		Comparable<Object> value2 = record2.get(getColumn());
+
+		// null values sort as if larger than non-null values
+		if (value1 == null && value2 == null) {
+			return 0;
+		} else if (value1 == null) {
+			return 1;
+		} else if (value2 == null) {
+			return -1;
+		}
+
+		return value1.compareTo(value2);
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/comparators/DataComparator.java

@@ -0,0 +1,32 @@
+package org.xbib.graphics.graph.gral.data.comparators;
+
+import java.util.Comparator;
+
+import org.xbib.graphics.graph.gral.data.Record;
+
+/**
+ * Abstract implementation of a {@code Comparator} for {@code Record} objects.
+ * This class allows to specify the index at which the records should be
+ * compared.
+ */
+public abstract class DataComparator implements Comparator<Record> {
+
+	/** Column that should be used for comparing. */
+	private final int column;
+
+	/**
+	 * Constructor.
+	 * @param col index of the column to be compared
+	 */
+	public DataComparator(int col) {
+		this.column = col;
+	}
+
+	/**
+	 * Returns the column to be compared.
+	 * @return column index
+	 */
+	public int getColumn() {
+		return column;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/comparators/Descending.java

@@ -0,0 +1,51 @@
+package org.xbib.graphics.graph.gral.data.comparators;
+
+import org.xbib.graphics.graph.gral.data.Record;
+
+/**
+ * Class that represents a {@code DataComparator} for comparing two records
+ * at a defined index for descending order.
+ */
+public class Descending extends DataComparator {
+
+	/**
+	 * Creates a new Descending object sorting according to the specified
+	 * column.
+	 * @param col Column index to be compared
+	 */
+	public Descending(int col) {
+		super(col);
+	}
+
+	/**
+	 * <p>Compares the values of two records at the specified column for order and
+	 * returns a corresponding integer:</p>
+	 * <ul>
+	 *   <li>a negative value means {@code record1} is larger than {@code record2}</li>
+	 *   <li>0 means {@code record1} is equal to {@code record2}</li>
+	 *   <li>a positive value means {@code record1} is smaller than {@code record2}</li>
+	 * </ul>
+	 * @param record1 First value
+	 * @param record2 Second value
+	 * @return An integer number describing the order:
+	 *         a negative value if {@code record1} is larger than {@code record2},
+	 *         0 if {@code record1} is equal to {@code record2},
+	 *         a positive value if {@code record1} is smaller than {@code record2},
+	 */
+	@SuppressWarnings("unchecked")
+	public int compare(Record record1, Record record2) {
+		Comparable<Object> value1 = record1.get(getColumn());
+		Comparable<Object> value2 = record2.get(getColumn());
+
+		// null values sort as if larger than non-null values
+		if (value1 == null && value2 == null) {
+			return 0;
+		} else if (value1 == null) {
+			return -1;
+		} else if (value2 == null) {
+			return 1;
+		}
+
+		return value2.compareTo(value1);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Accumulation.java

@@ -0,0 +1,43 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.util.Iterator;
+
+public class Accumulation<T extends Number & Comparable<T>> implements Filter<T> {
+
+	private final Iterable<T> data;
+
+	private static class AccumulationIterator<U extends Number> implements Iterator<Double> {
+		private final Iterator<U> wrappedIterator;
+		private double accumulatedValue;
+
+		public AccumulationIterator(Iterator<U> wrappedIterator) {
+			this.wrappedIterator = wrappedIterator;
+			accumulatedValue = 0.0;
+		}
+
+		@Override
+		public boolean hasNext() {
+			return wrappedIterator.hasNext();
+		}
+
+		@Override
+		public Double next() {
+			accumulatedValue += wrappedIterator.next().doubleValue();
+			return accumulatedValue;
+		}
+
+		@Override
+		public void remove() {
+			wrappedIterator.remove();
+		}
+	}
+
+	public Accumulation(Iterable<T> data) {
+		this.data = data;
+	}
+
+	@Override
+	public Iterator<Double> iterator() {
+		return new AccumulationIterator<>(data.iterator());
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Convolution.java

@@ -0,0 +1,98 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.util.DataUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+/**
+ * <p>Class that applies a specified kernel to a data source to convolve it.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Getting and setting the {@code Kernel} used for convolution</li>
+ * </ul>
+ */
+public class Convolution extends Filter2D {
+
+	/** Kernel that provides the values to convolve the data source. */
+	private final Kernel kernel;
+
+	/**
+	 * Initialized a new instance with the specified data source, convolution
+	 * kernel, edge handling mode, and columns to be filtered.
+	 * @param original DataSource to be filtered.
+	 * @param kernel Kernel to be used.
+	 * @param mode Mode of filtering.
+	 * @param cols Column indexes.
+	 */
+	public Convolution(DataSource original, Kernel kernel, Mode mode, int... cols) {
+		super(original, mode, cols);
+		this.kernel = kernel;
+		filter();
+	}
+
+	/**
+	 * Returns the kernel.
+	 * @return Kernel used for convolution.
+	 */
+	public Kernel getKernel() {
+		return kernel;
+	}
+
+	@Override
+	protected void filter() {
+		clear();
+		for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
+			Double[] filteredRow = new Double[getColumnCountFiltered()];
+			for (int colIndex = 0; colIndex < filteredRow.length; colIndex++) {
+				int colIndexOriginal = getIndexOriginal(colIndex);
+				filteredRow[colIndex] = convolve(colIndexOriginal, rowIndex);
+			}
+			add(filteredRow);
+		}
+	}
+
+	/**
+	 * Calculates the convolved value of the data with the specified column
+	 * and row.
+	 * @param col Column index.
+	 * @param row Row index.
+	 * @return Convolved value using the set kernel.
+	 */
+	private double convolve(int col, int row) {
+		Kernel kernel = getKernel();
+		if (kernel == null) {
+			Comparable<?> original = getOriginal(col, row);
+			return DataUtils.getValueOrDefault((Number) original, Double.NaN);
+		}
+		double sum = 0.0;
+		for (int k = kernel.getMinIndex(); k <= kernel.getMaxIndex(); k++) {
+			int r = row + k;
+			Comparable<?> original = getOriginal(col, r);
+			double v = DataUtils.getValueOrDefault((Number) original, Double.NaN);
+			if (!MathUtils.isCalculatable(v)) {
+				return v;
+			}
+			sum += kernel.get(k) * v;
+		}
+		return sum;
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Update caches
+		dataUpdated(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/ConvolutionFilter.java

@@ -0,0 +1,35 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.util.WindowIterator;
+
+public class ConvolutionFilter<T extends Number & Comparable<T>> implements Filter<T> {
+
+	private final List<Double> filtered;
+
+	private final Iterator<List<T>> windowIterator;
+
+	public ConvolutionFilter(Iterable<T> data, Kernel kernel) {
+		filtered = new LinkedList<>();
+
+		windowIterator = new WindowIterator<>(data.iterator(), kernel.size());
+
+		while (windowIterator.hasNext()) {
+			List<T> window = windowIterator.next();
+			double convolvedValue = 0.0;
+			for (int windowIndex = 0; windowIndex < window.size(); windowIndex++) {
+				int kernelIndex = windowIndex - kernel.getOffset();
+				convolvedValue += kernel.get(kernelIndex)*window.get(windowIndex).doubleValue();
+			}
+			filtered.add(convolvedValue);
+		}
+	}
+
+	@Override
+	public Iterator<Double> iterator() {
+		return filtered.iterator();
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Filter.java

@@ -0,0 +1,25 @@
+/*
+ * GRAL: GRAphing Library for Java(R)
+ *
+ * (C) Copyright 2009-2019 Erich Seifert <dev[at]erichseifert.de>,
+ * Michael Seifert <mseifert[at]error-reports.org>
+ *
+ * This file is part of GRAL.
+ *
+ * GRAL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRAL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with GRAL.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.xbib.graphics.graph.gral.data.filters;
+
+public interface Filter<T extends Comparable<T>> extends Iterable<Double> {
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Filter2D.java

@@ -0,0 +1,360 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+
+import org.xbib.graphics.graph.gral.data.AbstractDataSource;
+import org.xbib.graphics.graph.gral.data.DataChangeEvent;
+import org.xbib.graphics.graph.gral.data.DataListener;
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+/**
+ * <p>Abstract class that provides basic functions for filtering arbitrary
+ * columns of a DataSource, in other words a set of one-dimensional data.</p>
+ *
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Different modes for filtering (see {@link Mode})</li>
+ *   <li>Support for listening for changes of the original data</li>
+ *   <li>Filtering of multiple columns</li>
+ * </ul>
+ *
+ * <p>Values of filtered columns are buffered. Access to unfiltered columns is
+ * delegated to the original data source. Derived classes must make sure the
+ * caches are updated when deserialization is done. This can be done by calling
+ * {@code dataUpdated(this)} in a custom deserialization method.</p>
+ */
+public abstract class Filter2D extends AbstractDataSource
+		implements DataListener {
+
+	/** Type to define the behavior when engaging the borders of a column, i.e.
+	the filter would need more data values than available. */
+	public enum Mode {
+		/**	Ignore missing values. */
+		OMIT,
+		/**	Treat missing values as zero. */
+		ZERO,
+		/**	Repeat the last value. */
+		REPEAT,
+		/**	Mirror values at the last value. */
+		MIRROR,
+		/**	Repeat the data. */
+		CIRCULAR
+	}
+
+	/** Original data source. */
+	private final DataSource original;
+
+	/** Columns that should be filtered. */
+	private final int[] cols;
+	/** Data that was produced by the filter. */
+	private transient ArrayList<Double[]> rows;
+	/** Mode for handling. */
+	private Mode mode;
+
+	/**
+	 * Initializes a new instance with the specified data source, border
+	 * handling and columns to be filtered. The columns must be numeric,
+	 * otherwise an {@code IllegalArgumentException} is thrown.
+	 * @param original Data source to be filtered.
+	 * @param mode Border handling mode to be used.
+	 * @param cols Indexes of numeric columns to be filtered.
+	 */
+	@SuppressWarnings("unchecked")
+	public Filter2D(DataSource original, Mode mode, int... cols) {
+		this.rows = new ArrayList<>(original.getRowCount());
+		this.original = original;
+		this.mode = mode;
+
+		this.cols = Arrays.copyOf(cols, cols.length);
+		// A sorted array is necessary for binary search
+		Arrays.sort(this.cols);
+
+		// Check if columns are numeric
+		Class<? extends Comparable<?>>[] originalColumnTypes =
+			original.getColumnTypes();
+		for (int colIndex : this.cols) {
+			if (!original.isColumnNumeric(colIndex)) {
+				throw new IllegalArgumentException(MessageFormat.format(
+					"Column {0,number,integer} isn't numeric and cannot be filtered.", //$NON-NLS-1$
+					colIndex));
+			}
+		}
+
+		Class<? extends Comparable<?>>[] types = originalColumnTypes;
+		for (int colIndex : this.cols) {
+			types[colIndex] = Double.class;
+		}
+		setColumnTypes(types);
+
+		this.original.addDataListener(this);
+		dataUpdated(this.original);
+	}
+
+	/**
+	 * Returns the original data source that is filtered.
+	 * @return Original data source.
+	 */
+	protected DataSource getOriginal() {
+		return original;
+	}
+
+	/**
+	 * Returns the value of the original data source at the specified column
+	 * and row.
+	 * @param col Column index.
+	 * @param row Row index.
+	 * @return Original value.
+	 */
+	protected Comparable<?> getOriginal(int col, int row) {
+		int rowLast = original.getRowCount() - 1;
+		if (row < 0 || row > rowLast) {
+			if (getMode() == Mode.OMIT) {
+				return Double.NaN;
+			} else if (getMode() == Mode.ZERO) {
+				return 0.0;
+			} else if (getMode() == Mode.REPEAT) {
+				row = MathUtils.limit(row, 0, rowLast);
+			} else if (getMode() == Mode.MIRROR) {
+				int rem = Math.abs(row) / rowLast;
+				int mod = Math.abs(row) % rowLast;
+				if ((rem & 1) == 0) {
+					row = mod;
+				} else {
+					row = rowLast - mod;
+				}
+			} else if (getMode() == Mode.CIRCULAR) {
+				if (row >= 0) {
+					row = row % (rowLast + 1);
+				} else {
+					row = (row + 1) % (rowLast + 1) + rowLast;
+				}
+			}
+		}
+		return original.get(col, row);
+	}
+
+	/**
+	 * Clears this Filter2D.
+	 */
+	protected void clear() {
+		rows.clear();
+	}
+
+	/**
+	 * Adds the specified row data to this Filter2D.
+	 * @param rowData Row data to be added.
+	 */
+	protected void add(Double[] rowData) {
+		rows.add(rowData);
+	}
+
+	/**
+	 * Adds the specified row data to this Filter2D.
+	 * @param rowData Row to be added.
+	 */
+	protected void add(Number[] rowData) {
+		Double[] doubleData = new Double[rowData.length];
+		int i = 0;
+		for (Number value : rowData) {
+			doubleData[i++] = value.doubleValue();
+		}
+		rows.add(doubleData);
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		int colPos = getIndex(col);
+		if (colPos < 0) {
+			return original.get(col, row);
+		}
+		return rows.get(row)[colPos];
+	}
+
+	/**
+	 * Sets a new value for a specified cell.
+	 * @param col Column of the cell.
+	 * @param row Row of the cell.
+	 * @param value New cell value.
+	 * @return The previous value before it has been changed.
+	 */
+	protected Number set(int col, int row, Double value) {
+		int colPos = getIndex(col);
+		if (colPos < 0) {
+			throw new IllegalArgumentException(
+				"Can't set value in unfiltered column."); //$NON-NLS-1$
+		}
+		Double old = rows.get(row)[colPos];
+		rows.get(row)[colPos] = value;
+		notifyDataUpdated(new DataChangeEvent(this, col, row, old, value));
+		return old;
+	}
+
+	@Override
+	public int getColumnCount() {
+		return original.getColumnCount();
+	}
+
+	/**
+	 * Returns the number of filtered columns.
+	 * @return Number of filtered columns.
+	 */
+	protected int getColumnCountFiltered() {
+		if (cols.length == 0) {
+			return original.getColumnCount();
+		}
+		return cols.length;
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		return original.getRowCount();
+	}
+
+	/**
+	 * Returns the number of filtered rows.
+	 * @return Number of filtered rows.
+	 */
+	protected int getRowCountFiltered() {
+		return original.getRowCount();
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataAdded(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataUpdated(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been added, updated, or removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	private void dataChanged(DataSource source, DataChangeEvent... events) {
+		filter();
+	}
+
+	/**
+	 * Returns the index of the original column using the index of the
+	 * filtered column.
+	 * @param col Index of the filtered column
+	 * @return Index of the original column
+	 */
+	protected int getIndexOriginal(int col) {
+		if (cols.length == 0) {
+			return col;
+		}
+		return cols[col];
+	}
+
+	/**
+	 * Returns the index of the filtered column using the index of the
+	 * original column.
+	 * @param col Index of the original column
+	 * @return Index of the filtered column
+	 */
+	protected int getIndex(int col) {
+		if (cols.length == 0) {
+			return col;
+		}
+		return Arrays.binarySearch(cols, col);
+	}
+
+	/**
+	 * Returns whether the specified column is filtered.
+	 * @param col Column index.
+	 * @return True, if the column is filtered.
+	 */
+	protected boolean isFiltered(int col) {
+		return getIndex(col) >= 0;
+	}
+
+	/**
+	 * Invokes the filtering routine.
+	 */
+	protected abstract void filter();
+
+	/**
+	 * Returns the Mode of this Filter2D.
+	 * @return Mode of filtering.
+	 */
+	public Mode getMode() {
+		return mode;
+	}
+
+	/**
+	 * Sets the Mode the specified value.
+	 * @param mode Mode of filtering.
+	 */
+	public void setMode(Mode mode) {
+		this.mode = mode;
+		dataUpdated(this);
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Handle transient fields
+		rows = new ArrayList<>();
+
+		// Update caches
+		original.addDataListener(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Kernel.java

@@ -0,0 +1,228 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.util.Arrays;
+
+/**
+ * <p>Class that represents an one dimensional array of coefficients for a
+ * weighted filtering.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Adding of other kernels or scalars</li>
+ *   <li>Multiplication with other kernels or scalars</li>
+ *   <li>Normalization</li>
+ *   <li>Negation</li>
+ * </ul>
+ */
+public class Kernel {
+
+	/** Kernel values. */
+	private final double[] values;
+	/** Index of the kernel's center value. */
+	private final int offset;
+
+	/**
+	 * Creates a new Kernel object with the specified offset and values.
+	 * @param offset Offset to the first item in the kernel.
+	 * @param values Array of values in the kernel.
+	 */
+	public Kernel(int offset, double[] values) {
+		this.values = Arrays.copyOf(values, values.length);
+		this.offset = offset;
+	}
+
+	/**
+	 * Creates a new kernel object with the specified values and an offset
+	 * being half the size of this kernel (rounded down).
+	 * @param values Data values for the kernel.
+	 */
+	public Kernel(double... values) {
+		this(values.length/2, values);
+	}
+
+	/**
+	 * Returns a Kernel of specified variance with binomial coefficients.
+	 * @param variance Variance.
+	 * @return Kernel.
+	 */
+	public static Kernel getBinomial(double variance) {
+		int size = (int) (variance * 4.0) + 1;
+		return getBinomial(size);
+	}
+
+	/**
+	 * Returns a Kernel of specified size with binomial coefficients.
+	 * @param size Size of the Kernel.
+	 * @return Kernel.
+	 */
+	public static Kernel getBinomial(int size) {
+		double[] values = new double[size];
+		values[0] = 1.0;
+		for (int i = 0; i < size - 1; i++) {
+			values[0] /= 2.0;
+		}
+
+		for (int i = 0; i < size; i++) {
+			for (int j = i; j > 0; j--) {
+				values[j] += values[j - 1];
+			}
+		}
+
+		return new Kernel(values);
+	}
+
+	/**
+	 * Returns a Kernel with the specified size and offset, filled with a
+	 * single value.
+	 * @param size Size.
+	 * @param offset Offset.
+	 * @param value Value the Kernel is filled with.
+	 * @return Kernel.
+	 */
+	public static Kernel getUniform(int size, int offset, double value) {
+		double[] values = new double[size];
+		Arrays.fill(values, value);
+		return new Kernel(offset, values);
+	}
+
+	/**
+	 * Returns the value at the specified position of this kernel.
+	 * If the position exceeds the minimum or maximum index, 0.0 is
+	 * returned.
+	 * @param i Index to be returned.
+	 * @return Value at the specified index.
+	 */
+	public double get(int i) {
+		if (i < getMinIndex() || i > getMaxIndex()) {
+			return 0.0;
+		}
+		return values[i - getMinIndex()];
+	}
+
+	/**
+	 * Sets the specified index of this kernel to the specified value.
+	 * @param i Index to be changed.
+	 * @param v Value to be set.
+	 */
+	protected void set(int i, double v) {
+		if (i < getMinIndex() || i > getMaxIndex()) {
+			return;
+		}
+		values[i - getMinIndex()] = v;
+	}
+
+	/**
+	 * Returns the offset of this kernel.
+	 * @return Offset.
+	 */
+	public int getOffset() {
+		return offset;
+	}
+
+	/**
+	 * Returns the number of values in this kernel.
+	 * @return Number of values.
+	 */
+	public int size() {
+		return values.length;
+	}
+
+	/**
+	 * Returns the index of the "leftmost" value.
+	 * @return Minimal index.
+	 */
+	public int getMinIndex() {
+		return -getOffset();
+	}
+
+	/**
+	 * Returns the index of the "rightmost" value.
+	 * @return Maximal index.
+	 */
+	public int getMaxIndex() {
+		return size() - getOffset() - 1;
+	}
+
+	/**
+	 * Returns a new Kernel, where the specified value was added to each of
+	 * the items.
+	 * @param v Value to be added.
+	 * @return Kernel with new values.
+	 */
+	public Kernel add(double v) {
+		for (int i = 0; i < values.length; i++) {
+			values[i] += v;
+		}
+		return this;
+	}
+
+	/**
+	 * Returns a new Kernel, where the specified kernel was added.
+	 * @param k Kernel to be added.
+	 * @return Kernel with new values.
+	 */
+	public Kernel add(Kernel k) {
+		int min = getMinIndex();
+		int max = getMaxIndex();
+		if (size() > k.size()) {
+			min = k.getMinIndex();
+			max = k.getMaxIndex();
+		}
+		for (int i = min; i <= max; i++) {
+			set(i, get(i) + k.get(i));
+		}
+		return this;
+	}
+
+	/**
+	 * Returns a new Kernel, where the specified value was multiplied with
+	 * each of the items.
+	 * @param v Value to be multiplied.
+	 * @return Kernel with new values.
+	 */
+	public Kernel mul(double v) {
+		for (int i = 0; i < values.length; i++) {
+			values[i] *= v;
+		}
+		return this;
+	}
+
+	/**
+	 * Returns a new Kernel, where the specified kernel was multiplied.
+	 * @param k Kernel to be multiplied.
+	 * @return Kernel with new values.
+	 */
+	public Kernel mul(Kernel k) {
+		int min = getMinIndex();
+		int max = getMaxIndex();
+		if (size() > k.size()) {
+			min = k.getMinIndex();
+			max = k.getMaxIndex();
+		}
+		for (int i = min; i <= max; i++) {
+			set(i, get(i) * k.get(i));
+		}
+		return this;
+	}
+
+	/**
+	 * Returns a normalized Kernel so that the sum of all values equals 1.
+	 * @return Normalized Kernel.
+	 */
+	public Kernel normalize() {
+		double sum = 0.0;
+		for (double value : values) {
+			sum += value;
+		}
+		return mul(1.0/sum);
+	}
+
+	/**
+	 * Returns a Kernel with all values being negated.
+	 * @return Negated Kernel.
+	 */
+	public Kernel negate() {
+		mul(-1.0);
+		return this;
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Median.java

@@ -0,0 +1,162 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+
+/**
+ * <p>Class that calculates the median of a data sequence.</p>
+ * <ul>
+ *   <li>Setting and getting offset</li>
+ *   <li>Setting and getting window size</li>
+ * </ul>
+ */
+public class Median extends Filter2D {
+
+	/** Number of values in the window that will be used to calculate the
+	median. */
+	private int windowSize;
+	/** Start of the window. */
+	private int offset;
+
+	/**
+	 * Creates a new Median object with the specified DataSource, window
+	 * size, offset, Mode, and columns.
+	 * @param original DataSource to be filtered.
+	 * @param windowSize Number of rows to be used for the calculation of the
+	 *        median.
+	 * @param offset Offset from the current filtered value to the last value
+	 *        of the window.
+	 * @param mode Mode of filtering.
+	 * @param cols Column indexes.
+	 */
+	public Median(DataSource original, int windowSize, int offset,
+			Mode mode, int... cols) {
+		super(original, mode, cols);
+		this.windowSize = windowSize;
+		this.offset = offset;
+		filter();
+	}
+
+	@Override
+	protected void filter() {
+		clear();
+		if (getWindowSize() <= 0) {
+			return;
+		}
+		List<List<Double>> colWindows =
+				new ArrayList<>(getColumnCount());
+		for (int colIndex = 0; colIndex < getColumnCountFiltered(); colIndex++) {
+			int colIndexOriginal = getIndexOriginal(colIndex);
+			List<Double> window = new ArrayList<>(getWindowSize());
+			colWindows.add(window);
+			// Pre-fill window
+			for (int rowIndex = getOffset() - getWindowSize(); rowIndex < 0; rowIndex++) {
+				Comparable<?> vOrig = getOriginal(colIndexOriginal, rowIndex);
+				double v = ((Number) vOrig).doubleValue();
+				window.add(v);
+			}
+		}
+		for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
+			Double[] filteredRow = new Double[getColumnCountFiltered()];
+			for (int colIndex = 0; colIndex < filteredRow.length; colIndex++) {
+				List<Double> window = colWindows.get(colIndex);
+				if (window.size() >= getWindowSize()) {
+					window.remove(0);
+				}
+				int colIndexOriginal = getIndexOriginal(colIndex);
+				Comparable<?> vOrig = getOriginal(colIndexOriginal,
+						rowIndex - getOffset() + getWindowSize());
+				double v = ((Number) vOrig).doubleValue();
+				window.add(v);
+				filteredRow[colIndex] = median(window);
+			}
+			add(filteredRow);
+		}
+	}
+
+	/**
+	 * Calculates the median for the specified values in the window.
+	 * @param w List of values the median will be calculated for.
+	 * @return Median.
+	 */
+	private double median(List<Double> w) {
+		if (w.size() == 1) {
+			return w.get(0);
+		}
+		List<Double> window = new ArrayList<>(w.size());
+		for (Double v : w) {
+			if (!MathUtils.isCalculatable(v)) {
+				return Double.NaN;
+			}
+			window.add(v);
+		}
+		int medianIndex = MathUtils.randomizedSelect(
+				window, 0, window.size() - 1, window.size()/2);
+		double median = window.get(medianIndex);
+		if ((window.size() & 1) == 0) {
+			int medianUpperIndex = MathUtils.randomizedSelect(
+					window, 0, window.size() - 1, window.size()/2 + 1);
+			double medianUpper = window.get(medianUpperIndex);
+			median = (median + medianUpper)/2.0;
+		}
+		return median;
+	}
+
+	/**
+	 * Returns the size of the window which is used to calculate the median.
+	 * @return Number of rows used.
+	 */
+	public int getWindowSize() {
+		return windowSize;
+	}
+
+	/**
+	 * Set the size of the window which is used to calculate the median.
+	 * @param windowSize Number of rows used.
+	 */
+	public void setWindowSize(int windowSize) {
+		this.windowSize = windowSize;
+		dataUpdated(this);
+	}
+
+	/**
+	 * Returns the offset from the current value used to calculate the
+	 * median to the last value of the window.
+	 * @return Offset.
+	 */
+	public int getOffset() {
+		return offset;
+	}
+
+	/**
+	 * Sets the offset from the current value used to calculate the
+	 * median to the last value of the window.
+	 * @param offset Offset.
+	 */
+	public void setOffset(int offset) {
+		this.offset = offset;
+		dataUpdated(this);
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Update caches
+		dataUpdated(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/MedianFilter.java

@@ -0,0 +1,33 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import org.xbib.graphics.graph.gral.util.WindowIterator;
+
+public class MedianFilter<T extends Number & Comparable<T>> implements Filter<T> {
+
+	private final List<Double> filtered;
+
+	private final Iterator<List<T>> windowIterator;
+
+	public MedianFilter(Iterable<T> data, int windowSize) {
+		filtered = new LinkedList<>();
+
+		windowIterator = new WindowIterator<>(data.iterator(), windowSize);
+
+		while (windowIterator.hasNext()) {
+			List<T> window = windowIterator.next();
+			Statistics windowStatistics = new Statistics(window);
+			double median = windowStatistics.get(Statistics.MEDIAN);
+			filtered.add(median);
+		}
+	}
+
+	@Override
+	public Iterator<Double> iterator() {
+		return filtered.iterator();
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/filters/Resize.java

@@ -0,0 +1,187 @@
+package org.xbib.graphics.graph.gral.data.filters;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.Arrays;
+import java.util.Iterator;
+
+import org.xbib.graphics.graph.gral.data.Column;
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.DataTable;
+import org.xbib.graphics.graph.gral.data.Record;
+
+/**
+ * Filter2D to change the size of equally spaced data sources. All columns of the
+ * data sources must be numeric, otherwise an {@code IllegalArgumentException}
+ * will be thrown. The values of the scaled result are created by averaging.
+ */
+public class Resize extends Filter2D {
+
+	/** Number of columns. */
+	private final int cols;
+	/** Number of rows. */
+	private final int rows;
+
+	/**
+	 * Initializes a new data source from an original data source and a
+	 * specified number of rows and columns.
+	 * @param data Original data source.
+	 * @param cols Number of columns for new data source.
+	 * @param rows Number of rows for new data source.
+	 */
+	public Resize(DataSource data, int cols, int rows) {
+		super(data, Mode.ZERO);
+		this.cols = cols;
+		this.rows = rows;
+		filter();
+	}
+
+	@Override
+	public int getColumnCount() {
+		if (cols <= 0) {
+			return super.getColumnCount();
+		}
+		return cols;
+	}
+
+	@Override
+	public int getRowCount() {
+		if (rows <= 0) {
+			return super.getRowCount();
+		}
+		return rows;
+	}
+
+	@Override
+	public Comparable<?> get(int col, int row) {
+		if ((cols <= 0 || cols == getOriginal().getColumnCount()) &&
+			(rows <= 0 || rows == getOriginal().getRowCount())) {
+			return getOriginal(col, row);
+		}
+		return super.get(col, row);
+	}
+
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	@Override
+	protected void filter() {
+		clear();
+		DataSource original = getOriginal();
+		if ((getRowCount() == original.getRowCount())
+				&& (getColumnCount() == original.getColumnCount())) {
+			return;
+		}
+
+		DataSource data = original;
+		if (getRowCount() != original.getRowCount()) {
+			Class[] dataTypes = new Class[original.getColumnCount()];
+			Arrays.fill(dataTypes, Double.class);
+			DataTable avgRows = new DataTable(dataTypes);
+			fillWithEmptyRows(avgRows, getRowCount());
+
+			double step = original.getRowCount() / (double) getRowCount();
+			for (int colIndex = 0; colIndex < original.getColumnCount(); colIndex++) {
+				Column colData = original.getColumn(colIndex);
+				for (int rowIndex = 0; rowIndex < getRowCount(); rowIndex++) {
+					double start = rowIndex*step;
+					double end   = (rowIndex + 1)*step;
+					avgRows.set(colIndex, rowIndex,
+							average(colData, start, end));
+				}
+			}
+			data = avgRows;
+		}
+		if (getColumnCount() != original.getColumnCount()) {
+			Class[] dataTypes = new Class[getColumnCount()];
+			Arrays.fill(dataTypes, Double.class);
+			DataTable avgCols = new DataTable(dataTypes);
+			fillWithEmptyRows(avgCols, data.getRowCount());
+
+			double step = original.getColumnCount() / (double) getColumnCount();
+			for (int rowIndex = 0; rowIndex < data.getRowCount(); rowIndex++) {
+				Record rowData = data.getRecord(rowIndex);
+				for (int colIndex = 0; colIndex < getColumnCount(); colIndex++) {
+					double start = colIndex*step;
+					double end   = (colIndex + 1)*step;
+					avgCols.set(colIndex, rowIndex,
+							average(rowData, start, end));
+				}
+			}
+			data = avgCols;
+		}
+
+		for (int rowIndex = 0; rowIndex < data.getRowCount(); rowIndex++) {
+			Record row = data.getRecord(rowIndex);
+			Double[] rowValues = new Double[row.size()];
+			for (int columnIndex = 0; columnIndex < rowValues.length; columnIndex++) {
+				rowValues[columnIndex] = row.get(columnIndex);
+			}
+			add(rowValues);
+		}
+	}
+
+	/**
+	 * Utility method that fills a data table with empty rows.
+	 * @param data Data table that should be filled.
+	 * @param count Number of rows that were added.
+	 */
+	private static void fillWithEmptyRows(DataTable data, int count) {
+		while (data.getRowCount() < count) {
+			Double[] emptyRow = new Double[data.getColumnCount()];
+			Arrays.fill(emptyRow, 0.0);
+			data.add(emptyRow);
+		}
+	}
+
+	private static <T> Iterator<T> advance(Iterator<T> iterator, int elementCount) {
+		for (int elementIndex = 0; elementIndex < elementCount; elementIndex++) {
+			iterator.next();
+		}
+		return iterator;
+	}
+
+	/**
+	 * Calculates the arithmetic mean of all values between start and end.
+	 * @param data Values.
+	 * @param start Start index.
+	 * @param end End index.
+	 * @return Arithmetic mean.
+	 */
+	private static double average(Iterable<? extends Comparable<?>> data, double start, double end) {
+		int startFloor = (int) Math.floor(start);
+		int startCeil  = (int) Math.ceil(start);
+		int endFloor = (int) Math.floor(end);
+		int endCeil = (int) Math.ceil(end);
+
+		double sum = 0.0;
+		Iterator<? extends Comparable<?>> dataIterator = data.iterator();
+		advance(dataIterator, startFloor);
+		for (int i = startFloor; i < endCeil; i++) {
+			Number number = (Number) dataIterator.next();
+			double val = number.doubleValue();
+			if (i == startFloor && startCeil != start) {
+				sum += (startCeil - start) * val;
+			} else if (i == endCeil - 1 && endFloor != end) {
+				sum += (end - endFloor) * val;
+			} else {
+				sum += val;
+			}
+		}
+		return sum / (end - start);
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Update caches
+		dataUpdated(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/package-info.java

@@ -0,0 +1,25 @@
+/*
+ * GRAL: GRAphing Library for Java(R)
+ *
+ * (C) Copyright 2009-2019 Erich Seifert <dev[at]erichseifert.de>,
+ * Michael Seifert <mseifert[at]error-reports.org>
+ *
+ * This file is part of GRAL.
+ *
+ * GRAL is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRAL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with GRAL.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/**
+ * Data model classes. This package contains classes and interfaces for storing data for plots.
+ */
+package org.xbib.graphics.graph.gral.data;

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/statistics/AbstractHistogram2D.java

@@ -0,0 +1,112 @@
+package org.xbib.graphics.graph.gral.data.statistics;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+
+import org.xbib.graphics.graph.gral.data.AbstractDataSource;
+import org.xbib.graphics.graph.gral.data.DataChangeEvent;
+import org.xbib.graphics.graph.gral.data.DataListener;
+import org.xbib.graphics.graph.gral.data.DataSource;
+
+/**
+ * Abstract base class for histograms. Derived classes must
+ * make sure the {@code getColumnTypes()} method returns a correct array
+ * with column types.
+ * @see AbstractDataSource#setColumnTypes(Class...)
+ */
+public abstract class AbstractHistogram2D extends AbstractDataSource
+		implements DataListener {
+
+	/** Data source that is used to build the histogram. */
+	private final DataSource data;
+
+	/**
+	 * Initializes a new histograms with a data source.
+	 * @param data Data source to be analyzed.
+	 */
+	@SuppressWarnings("unchecked")
+	public AbstractHistogram2D(DataSource data) {
+		this.data = data;
+		this.data.addDataListener(this);
+	}
+
+	/**
+	 * Recalculates the histogram values.
+	 */
+	protected abstract void rebuildCells();
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataAdded(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataUpdated(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+		notifyDataRemoved(events);
+	}
+
+	/**
+	 * Method that is invoked when data has been added, updated, or removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been changed.
+	 */
+	private void dataChanged(DataSource source, DataChangeEvent... events) {
+		rebuildCells();
+	}
+
+	/**
+	 * Returns the data source associated to this histogram.
+	 * @return Data source
+	 */
+	public DataSource getData() {
+		return data;
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Restore listeners
+		data.addDataListener(this);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/statistics/Histogram.java

@@ -0,0 +1,71 @@
+package org.xbib.graphics.graph.gral.data.statistics;
+
+import java.util.Arrays;
+import java.util.Iterator;
+
+public class Histogram implements Iterable<Integer> {
+	private Iterable<Comparable<?>> data;
+	private Number[] breaks;
+	private Integer[] bins;
+
+	public Histogram(Iterable<Comparable<?>> data, int binCount) {
+		this(data, getEquidistantBreaks(data, binCount + 1));
+	}
+
+	public Histogram(Iterable<Comparable<?>> data, Number... breaks) {
+		if (breaks.length < 2) {
+			throw new IllegalArgumentException("Invalid break count: " + breaks.length +
+					" A histogram requires at least two breaks to form a bucket.");
+		}
+		this.data = data;
+		this.breaks = breaks;
+		int binCount = breaks.length - 1;
+		bins = new Integer[binCount];
+		Arrays.fill(bins, 0);
+
+		computeDistribution();
+	}
+
+	private static Number[] getEquidistantBreaks(Iterable<Comparable<?>> data, int breakCount) {
+		Number[] breaks = new Number[breakCount];
+		Statistics statistics = new Statistics(data);
+		double minValue = statistics.get(Statistics.MIN);
+		double maxValue = statistics.get(Statistics.MAX);
+		double range = maxValue - minValue;
+		int binCount = breakCount - 1;
+		double binWidth = range/binCount;
+		for (int breakIndex = 0; breakIndex < breaks.length; breakIndex++) {
+			breaks[breakIndex] = minValue + breakIndex*binWidth;
+		}
+		return breaks;
+	}
+
+	private void computeDistribution() {
+		for (Comparable<?> value : data) {
+			if (!(value instanceof Number)) {
+				continue;
+			}
+			for (int binIndex = 0; binIndex < bins.length; binIndex++) {
+				double lowerBinLimit = breaks[binIndex].doubleValue();
+				double upperBinLimit = breaks[binIndex + 1].doubleValue();
+				double doubleValue = ((Number) value).doubleValue();
+				if (doubleValue >= lowerBinLimit && doubleValue < upperBinLimit) {
+					bins[binIndex]++;
+				}
+			}
+		}
+	}
+
+	public int size() {
+		return breaks.length - 1;
+	}
+
+	public int get(int binIndex) {
+		return bins[binIndex];
+	}
+
+	@Override
+	public Iterator<Integer> iterator() {
+		return Arrays.asList(bins).iterator();
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/statistics/Histogram2D.java

@@ -0,0 +1,232 @@
+package org.xbib.graphics.graph.gral.data.statistics;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.graphics.Orientation;
+
+/**
+ * <p>View that aggregates the column values of an other data source into
+ * a histogram with cells. The cells size can be equally sized by defining
+ * a number of cells or breakpoints between histogram cells can be passed
+ * as an array to create unequally sized cells.</p>
+ * <p>For ease of use the histogram is a data source itself.</p>
+ */
+public class Histogram2D extends AbstractHistogram2D {
+
+	/** Direction in which all values will be aggregated. */
+	private final Orientation orientation;
+
+	/** Intervals that will be used for aggregation. */
+	private final List<Number[]> breaks;
+	/** Bin cells that store all aggregation counts. */
+	private final List<long[]> cellList;
+
+	/** Minimum values for cells. */
+	private transient Map<Integer, Long> cacheMin;
+	/** Maximum values for cells. */
+	private transient Map<Integer, Long> cacheMax;
+
+	private Histogram2D(DataSource data, Orientation orientation) {
+		super(data);
+		this.orientation = orientation;
+		breaks = new ArrayList<>();
+		cellList = new ArrayList<>();
+		cacheMin = new HashMap<>();
+		cacheMax = new HashMap<>();
+	}
+
+	/**
+	 * Creates a new AbstractHistogram2D object with the specified DataSource and
+	 * cell count.
+	 * @param data DataSource so be analyzed.
+	 * @param orientation Orientation of the histogram values.
+	 * @param breakCount Number of subdivisions for analysis.
+	 */
+	public Histogram2D(DataSource data, Orientation orientation,
+					   int breakCount) {
+		this(data, orientation);
+
+		// Create equally spaced breaks
+		int count = getData().getColumnCount();
+		if (orientation == Orientation.HORIZONTAL) {
+			count = getData().getRowCount();
+		}
+		for (int index = 0; index < count; index++) {
+			double min, max;
+			if (orientation == Orientation.HORIZONTAL) {
+				min = ((Number) getData().getRowStatistics(Statistics.MIN).get(0, index)).doubleValue();
+				max = ((Number) getData().getRowStatistics(Statistics.MAX).get(0, index)).doubleValue();
+			} else {
+				min = ((Number) getData().getColumnStatistics(Statistics.MIN).get(index, 0)).doubleValue();
+				max = ((Number) getData().getColumnStatistics(Statistics.MAX).get(index, 0)).doubleValue();
+			}
+			double delta = (max - min + Double.MIN_VALUE) / breakCount;
+
+			Number[] breaks = new Double[breakCount + 1];
+			for (int i = 0; i < breaks.length; i++) {
+				breaks[i] = min + i*delta;
+			}
+			this.breaks.add(breaks);
+		}
+		dataUpdated(getData());
+	}
+
+	/**
+	 * Initializes a new histogram with the specified data source and
+	 * subdivisions at the specified positions.
+	 * @param data Data source to be analyzed.
+	 * @param orientation Orientation in which the data should be sampled.
+	 * @param breaks Values of where a subdivision should occur.
+	 */
+	public Histogram2D(DataSource data, Orientation orientation,
+					   Number[]... breaks) {
+		this(data, orientation);
+		int count = getData().getColumnCount();
+		if (orientation == Orientation.HORIZONTAL) {
+			count = getData().getRowCount();
+		}
+		if (breaks.length != count) {
+			throw new IllegalArgumentException(MessageFormat.format(
+				"Invalid number of breaks: got {0,number,integer}, expected {1,number,integer}.", //$NON-NLS-1$
+				breaks.length, count));
+		}
+		Collections.addAll(this.breaks, breaks);
+		dataUpdated(getData());
+	}
+
+	/**
+	 * (Re-)populates the cells of this AbstractHistogram2D.
+	 */
+	@Override
+	protected void rebuildCells() {
+		// FIXME Very naive implementation
+		cellList.clear();
+		cacheMin.clear();
+		cacheMax.clear();
+
+		// Iterate over histogram data sets
+		int breakIndex = 0;
+		for (Number[] brk : breaks) {
+			long[] cells = new long[brk.length - 1];
+			long colMin = Long.MAX_VALUE;
+			long colMax = Long.MIN_VALUE;
+
+			Iterable<? extends Comparable<?>> data;
+			if (orientation == Orientation.VERTICAL) {
+				data = getData().getColumn(breakIndex);
+			} else {
+				data = getData().getRecord(breakIndex);
+			}
+
+			// Iterate over data cells
+			for (Comparable<?> cell : data) {
+				if (!(cell instanceof Number)) {
+					continue;
+				}
+				Number numericCell = (Number) cell;
+				double val = numericCell.doubleValue();
+				// Iterate over histogram rows
+				for (int i = 0; i < brk.length - 1; i++) {
+					// Put the value into corresponding class
+					if ((val >= brk[i].doubleValue())
+							&& (val < brk[i + 1].doubleValue())) {
+						cells[i]++;
+						if (cells[i] > colMax) {
+							colMax = cells[i];
+						}
+						if (cells[i] < colMin) {
+							colMin = cells[i];
+						}
+						break;
+					}
+				}
+			}
+			cellList.add(cells);
+			cacheMin.put(breakIndex, colMin);
+			cacheMax.put(breakIndex, colMax);
+			breakIndex++;
+		}
+	}
+
+	/**
+	 * Returns the direction in which the histogram values will be accumulated.
+	 * @return Horizontal or vertical orientation.
+	 */
+	public Orientation getOrientation() {
+		return orientation;
+	}
+
+	/**
+	 * Returns the minimum and maximum value of the specified cell.
+	 * @param col Column index.
+	 * @param cell Cell index.
+	 * @return Extent of the cell.
+	 */
+	public Number[] getCellLimits(int col, int cell) {
+		Number[] breaks = this.breaks.get(col);
+		Number lower = breaks[cell];
+		Number upper = breaks[cell + 1];
+		return new Number[] {lower, upper};
+	}
+
+	/**
+	 * Returns the row with the specified index.
+	 * @param col index of the column to return
+	 * @param row index of the row to return
+	 * @return the specified value of the data cell
+	 */
+	public Comparable<?> get(int col, int row) {
+		return cellList.get(col)[row];
+	}
+
+	/**
+	 * Returns the number of rows of the data source.
+	 * @return number of rows in the data source.
+	 */
+	public int getRowCount() {
+		int rowCount = 0;
+		for (long[] cells : this.cellList) {
+			rowCount = Math.max(cells.length, rowCount);
+		}
+		return rowCount;
+	}
+
+	@Override
+	public int getColumnCount() {
+		return cellList.size();
+	}
+
+	@Override
+	@SuppressWarnings({"unchecked","rawtypes"})
+	public Class<? extends Comparable<?>>[] getColumnTypes() {
+		Class<? extends Comparable<?>>[] types = new Class[getColumnCount()];
+		Arrays.fill(types, Long.class);
+		return types;
+	}
+
+	/**
+	 * Custom deserialization method.
+	 * @param in Input stream.
+	 * @throws ClassNotFoundException if a serialized class doesn't exist anymore.
+	 * @throws IOException if there is an error while reading data from the
+	 *         input stream.
+	 */
+	private void readObject(ObjectInputStream in)
+			throws ClassNotFoundException, IOException {
+		// Normal deserialization
+		in.defaultReadObject();
+
+		// Handle transient fields
+		cacheMin = new HashMap<>();
+		cacheMax = new HashMap<>();
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/data/statistics/Statistics.java

@@ -0,0 +1,204 @@
+package org.xbib.graphics.graph.gral.data.statistics;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.util.DataUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.SortedList;
+
+/**
+ * A class that computes and stores various statistical information
+ * for an Iterable of values.
+ */
+public class Statistics {
+	/** Key for specifying the total number of elements.
+	This is the zeroth central moment: E((x - µ)^0) */
+	public static final String N = "n"; //$NON-NLS-1$
+
+	/** Key for specifying the sum of all values. */
+	public static final String SUM = "sum"; //$NON-NLS-1$
+	/** Key for specifying the sum of all value squares. */
+	public static final String SUM2 = "sum2"; //$NON-NLS-1$
+	/** Key for specifying the sum of all value cubics. */
+	public static final String SUM3 = "sum3"; //$NON-NLS-1$
+	/** Key for specifying the sum of all value quads. */
+	public static final String SUM4 = "sum4"; //$NON-NLS-1$
+
+	/** Key for specifying the minimum, i.e. the smallest value. */
+	public static final String MIN = "min"; //$NON-NLS-1$
+	/** Key for specifying the maximum, i.e. the largest value. */
+	public static final String MAX = "max"; //$NON-NLS-1$
+
+	/** Key for specifying the arithmetic mean of all values. */
+	public static final String MEAN = "mean"; //$NON-NLS-1$
+	/** Key for specifying the sum of squared differences.
+	This is identical to the second central moment: E((x - mean)^2) */
+	public static final String SUM_OF_DIFF_SQUARES = "M2"; //$NON-NLS-1$
+	/** Key for specifying the sum of squared differences.
+	This is identical to the third central moment: E((x - mean)^3) */
+	public static final String SUM_OF_DIFF_CUBICS = "M3"; //$NON-NLS-1$
+	/** Key for specifying the sum of squared differences.
+	This is identical to the fourth central moment: E((x - mean)^4) */
+	public static final String SUM_OF_DIFF_QUADS = "M4"; //$NON-NLS-1$
+	/** Key for specifying the variance of a sample. Formula:
+	{@code 1/(N - 1) * sumOfSquares} */
+	public static final String VARIANCE = "sample variance"; //$NON-NLS-1$
+	/** Key for specifying the population variance. Formula:
+	{@code 1/N * sumOfSquares} */
+	public static final String POPULATION_VARIANCE = "population variance"; //$NON-NLS-1$
+	/** Key for specifying the skewness. */
+	public static final String SKEWNESS = "skewness"; //$NON-NLS-1$
+	/** Key for specifying the kurtosis. */
+	public static final String KURTOSIS = "kurtosis"; //$NON-NLS-1$
+
+	/** Key for specifying the median (or 50% quantile). */
+	public static final String MEDIAN = "quantile50"; //$NON-NLS-1$
+	/** Key for specifying the 1st quartile (or 25th quantile). */
+	public static final String QUARTILE_1 = "quantile25"; //$NON-NLS-1$
+	/** Key for specifying the 2nd quartile (or 50th quantile). */
+	public static final String QUARTILE_2 = "quantile50"; //$NON-NLS-1$
+	/** Key for specifying the 3rd quartile (or 75th quantile). */
+	public static final String QUARTILE_3 = "quantile75"; //$NON-NLS-1$
+
+	/** Data values that are used to build statistical aggregates. */
+	private final Iterable<? extends Comparable<?>> data;
+	/** Table statistics stored by key. */
+	private final Map<String, Double> statistics;
+
+	/**
+	 * Initializes a new object with the specified data values.
+	 * @param data Data to be analyzed.
+	 */
+	public Statistics(Iterable<? extends Comparable<?>> data) {
+		statistics = new HashMap<>();
+		this.data = data;
+	}
+
+	/**
+	 * Utility method that calculates basic statistics like element count, sum,
+	 * or mean.
+	 *
+	 * Notes: Calculation of higher order statistics is based on formulas from
+	 * http://people.xiph.org/~tterribe/notes/homs.html
+	 *
+	 * @param data Data values used to calculate statistics
+	 * @param stats A {@code Map} that should store the new statistics.
+	 */
+	private void createBasicStats(Iterable<? extends Comparable<?>> data, Map<String, Double> stats) {
+		double n = 0.0;
+		double sum = 0.0;
+		double sum2 = 0.0;
+		double sum3 = 0.0;
+		double sum4 = 0.0;
+		double mean = 0.0;
+		double sumOfDiffSquares = 0.0;
+		double sumOfDiffCubics = 0.0;
+		double sumOfDiffQuads = 0.0;
+
+		for (Comparable<?> cell : data) {
+			if (!(cell instanceof Number)) {
+				continue;
+			}
+			Number numericCell = (Number) cell;
+			if (!MathUtils.isCalculatable(numericCell)) {
+				continue;
+			}
+			double val = numericCell.doubleValue();
+
+			if (!stats.containsKey(MIN) || val < stats.get(MIN)) {
+				stats.put(MIN, val);
+			}
+			if (!stats.containsKey(MAX) || val > stats.get(MAX)) {
+				stats.put(MAX, val);
+			}
+
+			n++;
+
+			double val2 = val*val;
+			sum += val;
+			sum2 += val2;
+			sum3 += val2*val;
+			sum4 += val2*val2;
+
+			double delta = val - mean;
+			double deltaN = delta/n;
+			double deltaN2 = deltaN*deltaN;
+			double term1 = delta*deltaN*(n - 1.0);
+			mean += deltaN;
+			sumOfDiffQuads += term1*deltaN2*(n*n - 3.0*n + 3.0) +
+				6.0*deltaN2*sumOfDiffSquares - 4.0*deltaN*sumOfDiffCubics;
+			sumOfDiffCubics += term1*deltaN*(n - 2.0) -
+				3.0*deltaN*sumOfDiffSquares;
+			sumOfDiffSquares += term1;
+		}
+
+		stats.put(N, n);
+		stats.put(SUM,  sum);
+		stats.put(SUM2, sum2);
+		stats.put(SUM3, sum3);
+		stats.put(SUM4, sum4);
+		stats.put(MEAN, mean);
+		stats.put(SUM_OF_DIFF_QUADS, sumOfDiffQuads);
+		stats.put(SUM_OF_DIFF_CUBICS, sumOfDiffCubics);
+		stats.put(SUM_OF_DIFF_SQUARES, sumOfDiffSquares);
+
+		stats.put(VARIANCE, sumOfDiffSquares/(n - 1.0));
+		stats.put(POPULATION_VARIANCE, sumOfDiffSquares/n);
+		stats.put(SKEWNESS,
+			(sumOfDiffCubics/n)/Math.pow(sumOfDiffSquares/n, 3.0/2.0) - 3.0);
+		stats.put(KURTOSIS,
+			(n*sumOfDiffQuads)/(sumOfDiffSquares*sumOfDiffSquares) - 3.0);
+	}
+
+	/**
+	 * Utility method that calculates quantiles for the given data values and
+	 * stores the results in {@code stats}.
+	 * @param stats {@code Map} for storing results
+	 * @see MathUtils#quantile(List,double)
+	 */
+	private void createDistributionStats(Iterable<? extends Comparable<?>> data, Map<String, Double> stats) {
+		// Create sorted list of data
+		List<Double> values = new SortedList<>();
+		for (Comparable<?> cell : data) {
+			if (!(cell instanceof Number)) {
+				continue;
+			}
+			Number numericCell = (Number) cell;
+			double value = numericCell.doubleValue();
+			if (MathUtils.isCalculatable(value)) {
+				values.add(value);
+			}
+		}
+
+		if (values.size() <= 0) {
+			return;
+		}
+
+		stats.put(QUARTILE_1, MathUtils.quantile(values, 0.25));
+		stats.put(QUARTILE_2, MathUtils.quantile(values, 0.50));
+		stats.put(QUARTILE_3, MathUtils.quantile(values, 0.75));
+		stats.put(MEDIAN, stats.get(QUARTILE_2));
+	}
+
+	/**
+	 * Returns the specified statistics value.
+	 * @param key Requested information.
+	 * @return The value for the specified key as value, or <i>NaN</i>
+	 *         if the specified statistical value does not exist
+	 */
+	public double get(String key) {
+		if (!statistics.containsKey(key)) {
+			if (MEDIAN.equals(key) || QUARTILE_1.equals(key) ||
+					QUARTILE_2.equals(key) || QUARTILE_3.equals(key)) {
+				createDistributionStats(data, statistics);
+			} else {
+				createBasicStats(data, statistics);
+			}
+		}
+
+		Double v = statistics.get(key);
+		return DataUtils.getValueOrDefault(v, Double.NaN);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/AbstractDrawable.java

@@ -0,0 +1,97 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+
+/**
+ * Abstract implementation of the {@link Drawable} interface.
+ * This class implements common functionality like the different ways for
+ * getting and setting the bounding rectangle of the drawable object.
+ */
+public abstract class AbstractDrawable implements Drawable {
+
+	/** Boundaries of the drawable object. */
+	private final Rectangle2D bounds;
+
+	/**
+	 * Creates an AbstractDrawable.
+	 */
+	public AbstractDrawable() {
+		bounds = new Rectangle2D.Double();
+	}
+
+	/**
+	 * Returns the bounds of this {@code Drawable}.
+	 * @return a bounding rectangle
+	 */
+	public Rectangle2D getBounds() {
+		Rectangle2D b = new Rectangle2D.Double();
+		b.setFrame(bounds);
+		return b;
+	}
+
+	/**
+	 * Returns the x-position of the bounds.
+	 * @return horizontal position of the upper-left corner of the bounding
+	 *         rectangle.
+	 */
+	public double getX() {
+		return bounds.getX();
+	}
+	/**
+	 * Returns the y-position of the bounds.
+	 * @return vertical position of the upper-left corner of the bounding
+	 *         rectangle.
+	 */
+	public double getY() {
+		return bounds.getY();
+	}
+
+	/**
+	 * Returns the width of the bounds.
+	 * @return horizontal extent.
+	 */
+	public double getWidth() {
+		return bounds.getWidth();
+	}
+	/**
+	 * Returns the height of the bounds.
+	 * @return vertical extent.
+	 */
+	public double getHeight() {
+		return bounds.getHeight();
+	}
+
+	/**
+	 * Sets the bounds to the specified bounding rectangle.
+	 * @param bounds rectangle containing the component.
+	 */
+	public void setBounds(Rectangle2D bounds) {
+		setBounds(bounds.getX(), bounds.getY(),
+			bounds.getWidth(), bounds.getHeight());
+	}
+	/**
+	 * Sets the bounds to the specified coordinates, width and height.
+	 * This method should be used when overriding functionality.
+	 * @param x horizontal position of the upper-left corner
+	 * @param y vertical position of the upper-left corner
+	 * @param width horizontal extent
+	 * @param height vertical extent
+	 */
+	public void setBounds(double x, double y, double width, double height) {
+		bounds.setFrame(x, y, width, height);
+	}
+
+	/**
+	 * Returns the preferred size of the {@code Drawable}.
+	 * @return horizontal and vertical extent that wants to be reached
+	 */
+	public Dimension2D getPreferredSize() {
+		return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double();
+	}
+
+	@Override
+	public void setPosition(double x, double y) {
+		bounds.setFrame(x, y, bounds.getWidth(), bounds.getHeight());
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Container.java

@@ -0,0 +1,113 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.graphics.layout.Layout;
+
+/**
+ * An interface that provides functions to build a group of multiple components
+ * of {@link Drawable}. It is also responsible for managing layout of its
+ * components using a {@link Layout} and layout constraints for each component.
+ */
+public interface Container extends Iterable<Drawable> {
+	/**
+	 * Returns the space that this container must preserve at each of its
+	 * edges.
+	 * @return The insets of this DrawableContainer
+	 */
+	Insets2D getInsets();
+
+	/**
+	 * Sets the space that this container must preserve at each of its
+	 * edges.
+	 * @param insets Insets to be set.
+	 */
+	void setInsets(Insets2D insets);
+
+	/**
+	 * Returns the bounds of this container.
+	 * @return bounds
+	 */
+	Rectangle2D getBounds();
+
+	/**
+	 * Sets the bounds of this container.
+	 * @param bounds Bounds
+	 */
+	void setBounds(Rectangle2D bounds);
+
+	/**
+	 * Returns the layout associated with this container.
+	 * @return Layout manager
+	 */
+	Layout getLayout();
+
+	/**
+	 * Recalculates this container's layout.
+	 */
+	void layout();
+
+	/**
+	 * Sets the layout associated with this container.
+	 * @param layout Layout to be set.
+	 */
+	void setLayout(Layout layout);
+
+	/**
+	 * Adds a new component to this container.
+	 * @param drawable Component
+	 */
+	void add(Drawable drawable);
+
+	/**
+	 * Adds a new component to this container.
+	 * @param drawable Component
+	 * @param constraints Additional information (e.g. for layout)
+	 */
+	void add(Drawable drawable, Object constraints);
+
+	/**
+	 * Returns whether the specified {@code Drawable} is stored.
+	 * @param drawable Element to be checked.
+	 * @return {@code true} if the element is stored in the {@code Container},
+	 * {@code false} otherwise.
+	 */
+	boolean contains(Drawable drawable);
+
+	/**
+	 * Returns the components at the specified point.
+	 * The first component in the result {@code List} is the most
+	 * specific component, i.e. the component with the deepest nesting level.
+	 * If no component could be found an empty {@code List} will be returned.
+	 * @param point Two-dimensional point.
+	 * @return Components at the specified point, with the deepest nested component first.
+	 */
+	List<Drawable> getDrawablesAt(Point2D point);
+
+	/**
+	 * Returns a list of stored components.
+	 * @return Contained drawables.
+	 */
+	List<Drawable> getDrawables();
+
+	/**
+	 * Return additional information on component
+	 * @param drawable Component
+	 * @return Information object or {@code null}
+	 */
+	Object getConstraints(Drawable drawable);
+
+	/**
+	 * Removes a component from this container.
+	 * @param drawable Component
+	 */
+	void remove(Drawable drawable);
+
+	/**
+	 * Returns the number of components that are stored in this container.
+	 * @return total number of components
+	 */
+	int size();
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Dimension2D.java

@@ -0,0 +1,85 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.util.Locale;
+
+/**
+ * <p>Class that stores the horizontal and vertical extent of an object.</p>
+ * <p>This implementation adds support of double values to
+ * {@code java.awt.geom.Dimension2D}.</p>
+ */
+public abstract class Dimension2D extends java.awt.geom.Dimension2D {
+
+	/**
+	 * Creates a new Dimension2D object.
+	 */
+	public Dimension2D() {
+	}
+
+	/**
+	 * Class that stores double values.
+	 */
+	public static class Double extends Dimension2D {
+
+		/** Horizontal extension. */
+		private double width;
+		/** Vertical extension. */
+		private double height;
+
+		/**
+		 * Creates a new Dimension2D object with zero width and height.
+		 */
+		public Double() {
+			setSize(0.0, 0.0);
+		}
+
+		/**
+		 * Creates a new Dimension2D object with the specified width and
+		 * height.
+		 * @param width Width.
+		 * @param height Height.
+		 */
+		public Double(double width, double height) {
+			setSize(width, height);
+		}
+
+		@Override
+		public double getHeight() {
+			return height;
+		}
+
+		@Override
+		public double getWidth() {
+			return width;
+		}
+
+		@Override
+		public void setSize(double width, double height) {
+			this.width = width;
+			this.height = height;
+		}
+
+		@Override
+		public String toString() {
+			return String.format(Locale.US,
+					"%s[width=%f, height=%f]", //$NON-NLS-1$
+					getClass().getName(), width, height);
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+			if (!(obj instanceof java.awt.geom.Dimension2D)) {
+				return false;
+			}
+			java.awt.geom.Dimension2D dim = (java.awt.geom.Dimension2D) obj;
+			return (getWidth() == dim.getWidth()) &&
+				(getHeight() == dim.getHeight());
+		}
+
+		@Override
+		public int hashCode() {
+			long bits = java.lang.Double.doubleToLongBits(getWidth());
+			bits ^= java.lang.Double.doubleToLongBits(getHeight()) * 31;
+			return ((int) bits) ^ ((int) (bits >> 32));
+		}
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Drawable.java

@@ -0,0 +1,76 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+
+
+/**
+ * Interface providing functions for a lightweight component that can be drawn
+ * on the screen. Functions include management of the bounding rectangle,
+ * returning a preferred size for layout operations, or drawing using a
+ * specified context.
+ */
+public interface Drawable {
+	/**
+	 * Returns the bounds of this {@code Drawable}.
+	 * @return a bounding rectangle
+	 */
+	Rectangle2D getBounds();
+	/**
+	 * Sets the bounds to the specified bounding rectangle.
+	 * @param bounds rectangle containing the component.
+	 */
+	void setBounds(Rectangle2D bounds);
+	/**
+	 * Sets the bounds to the specified coordinates, width and height.
+	 * This method should be used when overriding functionality.
+	 * @param x horizontal position of the upper-left corner
+	 * @param y vertical position of the upper-left corner
+	 * @param width horizontal extent
+	 * @param height vertical extent
+	 */
+	void setBounds(double x, double y, double width, double height);
+
+	/**
+	 * Returns the x-position of the bounds.
+	 * @return horizontal position of the upper-left corner of the bounding
+	 * rectangle
+	 */
+	double getX();
+	/**
+	 * Returns the y-position of the bounds.
+	 * @return vertical position of the upper-left corner of the bounding
+	 * rectangle
+	 */
+	double getY();
+
+	/**
+	 * Sets the position to the specified coordinates.
+	 * @param x Coordinate on the x-axis.
+	 * @param y Coordinate on the y-axis.
+	 */
+	void setPosition(double x, double y);
+
+	/**
+	 * Returns the width of the bounds.
+	 * @return horizontal extent
+	 */
+	double getWidth();
+	/**
+	 * Returns the height of the bounds.
+	 * @return vertical extent
+	 */
+	double getHeight();
+
+	/**
+	 * Returns the preferred size of the {@code Drawable}.
+	 * @return horizontal and vertical extent that wants to be reached
+	 */
+	Dimension2D getPreferredSize();
+
+	/**
+	 * Draws the {@code Drawable} with the specified drawing context.
+	 * @param context Environment used for drawing
+	 */
+	void draw(DrawingContext context);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/DrawableContainer.java

@@ -0,0 +1,243 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+import org.xbib.graphics.graph.gral.graphics.layout.Layout;
+
+/**
+ * Implementation of {@code Container} that is a {@code Drawable}
+ * itself and stores instances of {@code Drawable} as components.
+ * It takes care of laying out, managing insets for and painting the
+ * components.
+ *
+ * @see Drawable
+ * @see Container
+ */
+public class DrawableContainer extends AbstractDrawable implements Container {
+
+	/** Empty margins that should be preserved around the contents of this
+	    container. */
+	private final Insets2D insets;
+	/** Object that manages the layout of all container components. */
+	private Layout layout;
+	/** Elements stored in this container. */
+	private final Queue<Drawable> components;
+	/** Supplemental information for components, like layout constraints. */
+	private final Map<Drawable, Object> constraints;
+
+	/**
+	 * Creates a new container for {@code Drawable}s without layout
+	 * manager.
+	 */
+	public DrawableContainer() {
+		this(null);
+	}
+
+	/**
+	 * Creates a new container for {@code Drawable}s with the specified
+	 * layout manager.
+	 * @param layout Layout manager to be set.
+	 */
+	public DrawableContainer(Layout layout) {
+		insets = new Insets2D.Double();
+		components = new ConcurrentLinkedQueue<>();
+		constraints = new HashMap<>();
+		this.layout = layout;
+	}
+
+	/**
+	 * Draws the {@code Drawable} with the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	public void draw(DrawingContext context) {
+		drawComponents(context);
+	}
+
+	/**
+	 * Invokes the draw method of each {@code Drawable}.
+	 * @param context Environment used for drawing.
+	 */
+	protected void drawComponents(DrawingContext context) {
+		for (Drawable d : this) {
+			d.draw(context);
+		}
+	}
+
+	/**
+	 * Adds a new component to this container.
+	 * @param drawable Component
+	 */
+	public void add(Drawable drawable) {
+		add(drawable, null);
+	}
+
+	/**
+	 * Adds a new component to this container.
+	 * @param drawable Component
+	 * @param constraints Additional information (e.g. for layout)
+	 */
+	public void add(Drawable drawable, Object constraints) {
+		if (drawable == this) {
+			throw new IllegalArgumentException(
+				"A container cannot be added to itself."); //$NON-NLS-1$
+		}
+		this.constraints.put(drawable, constraints);
+		components.add(drawable);
+		layout();
+	}
+
+	@Override
+	public boolean contains(Drawable drawable) {
+		return components.contains(drawable);
+	}
+
+	@Override
+	public List<Drawable> getDrawablesAt(Point2D point) {
+		return getDrawablesAt(this, point, new LinkedList<Drawable>());
+	}
+
+	@Override
+	public List<Drawable> getDrawables() {
+		/*
+		 * TODO: Size of ArrayList can be different from the number of added components
+		 * in concurrent environments.
+		 */
+		List<Drawable> drawableList = new ArrayList<>(components.size());
+		drawableList.addAll(components);
+		return drawableList;
+	}
+
+	private static List<Drawable> getDrawablesAt(Container container, Point2D point, LinkedList<Drawable> previousResults) {
+		if (container instanceof Drawable && container.getBounds().contains(point)) {
+			previousResults.addFirst((Drawable) container);
+		}
+		for (Drawable component : container) {
+			// Check whether the point is in one of the child elements of the container
+			if (component instanceof Container) {
+				getDrawablesAt((Container) component, point, previousResults);
+			} else if (component != null && component.getBounds().contains(point)) {
+				previousResults.addFirst(component);
+			}
+		}
+		return previousResults;
+	}
+
+	/**
+	 * Return additional information on component
+	 * @param drawable Component
+	 * @return Information object or {@code null}
+	 */
+	public Object getConstraints(Drawable drawable) {
+		return constraints.get(drawable);
+	}
+
+	/**
+	 * Removes a component from this container.
+	 * @param drawable Component
+	 */
+	public void remove(Drawable drawable) {
+		components.remove(drawable);
+		constraints.remove(drawable);
+		layout();
+	}
+
+	/**
+	 * Returns the space that this container must preserve at each of its
+	 * edges.
+	 * @return The insets of this DrawableContainer
+	 */
+	public Insets2D getInsets() {
+		Insets2D insets = new Insets2D.Double();
+		insets.setInsets(this.insets);
+		return insets;
+	}
+
+	/**
+	 * Sets the space that this container must preserve at each of its
+	 * edges.
+	 * @param insets Insets to be set.
+	 */
+	public void setInsets(Insets2D insets) {
+		if (insets == this.insets || this.insets.equals(insets)) {
+			return;
+		}
+		this.insets.setInsets(insets);
+		layout();
+	}
+
+	/**
+	 * Returns the layout associated with this container.
+	 * @return Layout manager
+	 */
+	public Layout getLayout() {
+		return layout;
+	}
+
+	/**
+	 * Sets the layout associated with this container.
+	 * @param layout Layout to be set.
+	 */
+	public void setLayout(Layout layout) {
+		this.layout = layout;
+		layout();
+	}
+
+	/**
+	 * Recalculates this container's layout.
+	 */
+	public void layout() {
+		Layout layout = getLayout();
+		if (layout != null) {
+			layout.layout(this);
+		}
+	}
+
+    /**
+     * Returns an iterator over the container's elements.
+     *
+     * @return an Iterator.
+     */
+	public Iterator<Drawable> iterator() {
+		return components.iterator();
+	}
+
+	/**
+	 * Returns the number of components that are stored in this container.
+	 * @return total number of components
+	 */
+	public int size() {
+		return components.size();
+	}
+
+	@Override
+	public void setBounds(Rectangle2D bounds) {
+		super.setBounds(bounds);
+		layout();
+	}
+
+	@Override
+	public void setBounds(double x, double y, double width, double height) {
+		super.setBounds(x, y, width, height);
+		layout();
+	}
+
+	@Override
+	public Dimension2D getPreferredSize() {
+		Layout layout = getLayout();
+		if (layout != null) {
+			return layout.getPreferredSize(this);
+		}
+		return super.getPreferredSize();
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/DrawingContext.java

@@ -0,0 +1,83 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.Graphics2D;
+
+/**
+ * Class that stores an object for drawing and additional context information
+ * that may be necessary to determine how to draw the object. This includes
+ * information on drawing quality and the target media (screen, paper, etc.).
+ */
+public class DrawingContext {
+	/**
+	 * Data type that describes the quality mode of drawing operations.
+	 */
+	public enum Quality {
+		/** Fast drawing mode. */
+		DRAFT,
+		/** Standard drawing mode. */
+		NORMAL,
+		/** High quality drawing mode. */
+		QUALITY
+	}
+
+	/**
+	 * Data type that describes the type of the drawing target.
+	 */
+	public enum Target {
+		/** Bitmap drawing target consisting of pixels. */
+		BITMAP,
+		/** Vector drawing target consisting of lines and curves. */
+		VECTOR
+	}
+
+	/** Graphics instance used for drawing. */
+	private final Graphics2D graphics;
+	/** Quality level used for drawing. */
+	private final Quality quality;
+	/** Target media. */
+	private final Target target;
+
+	/**
+	 * Initializes a new context with a {@code Graphics2D} object.
+	 * @param graphics Object for drawing geometry.
+	 */
+	public DrawingContext(Graphics2D graphics) {
+		this(graphics, Quality.NORMAL, Target.BITMAP);
+	}
+
+	/**
+	 * Initializes a new context with a {@code Graphics2D} object.
+	 * @param graphics Object for drawing geometry.
+	 * @param quality Drawing quality.
+	 * @param target Target media.
+	 */
+	public DrawingContext(Graphics2D graphics, Quality quality, Target target) {
+		this.graphics = graphics;
+		this.quality = quality;
+		this.target = target;
+	}
+
+	/**
+	 * Returns the object for drawing geometry.
+	 * @return Graphics object.
+	 */
+	public Graphics2D getGraphics() {
+		return graphics;
+	}
+
+	/**
+	 * Returns the desired display quality.
+	 * @return Display quality mode.
+	 */
+	public Quality getQuality() {
+		return quality;
+	}
+
+	/**
+	 * Returns the drawing target.
+	 * @return Drawing target.
+	 */
+	public Target getTarget() {
+		return target;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Insets2D.java

@@ -0,0 +1,184 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.util.Locale;
+
+/**
+ * Abstract class that stores insets for all four directions.
+ * <p>Please use this instead of java.awt.Insets, as the java class does not
+ * support double values.</p>
+ */
+public abstract class Insets2D {
+
+	/**
+	 * Creates a new Insets2D object.
+	 */
+	public Insets2D() {
+	}
+
+	/**
+	 * Returns the insets at the top.
+	 * @return Top insets.
+	 */
+	public abstract double getTop();
+
+	/**
+	 * Returns the insets at the left.
+	 * @return Left insets.
+	 */
+	public abstract double getLeft();
+
+	/**
+	 * Returns the insets at the bottom.
+	 * @return Bottom insets.
+	 */
+	public abstract double getBottom();
+
+	/**
+	 * Returns the insets at the right.
+	 * @return Right insets.
+	 */
+	public abstract double getRight();
+
+	/**
+	 * Returns the sum of horizontal insets.
+	 * @return Horizontal insets.
+	 */
+	public double getHorizontal() {
+		return getRight() + getLeft();
+	}
+
+	/**
+	 * Returns the sum of vertical insets.
+	 * @return Vertical insets.
+	 */
+	public double getVertical() {
+		return getTop() + getBottom();
+	}
+
+	/**
+	 * Sets the insets according to the specified insets.
+	 * @param insets Insets to be set.
+	 */
+	public abstract void setInsets(Insets2D insets);
+
+	/**
+	 * Sets the insets to the specified values.
+	 * @param top Top insets.
+	 * @param left Left insets.
+	 * @param bottom Bottom insets.
+	 * @param right Right insets.
+	 */
+	public abstract void setInsets(double top, double left,
+			double bottom, double right);
+
+	/**
+	 * Class that stores insets as double values.
+	 */
+	public static class Double extends Insets2D {
+		/** Version id for serialization. */
+		private static final long serialVersionUID = -6637052175330595647L;
+
+		/** Top. */
+		private double top;
+		/** Left. */
+		private double left;
+		/** Bottom. */
+		private double bottom;
+		/** Right. */
+		private double right;
+
+		/**
+		 * Creates a new Insets2D object with zero insets.
+		 */
+		public Double() {
+			this(0.0);
+		}
+
+		/**
+		 * Creates a new Insets2D object with the specified insets in all
+		 * directions.
+		 * @param inset Inset value.
+		 */
+		public Double(double inset) {
+			this(inset, inset, inset, inset);
+		}
+
+		/**
+		 * Creates a new Insets2D object with the specified insets.
+		 * @param top Top insets.
+		 * @param left Left insets.
+		 * @param bottom Bottom insets.
+		 * @param right Right insets.
+		 */
+		public Double(double top, double left, double bottom, double right) {
+			setInsets(top, left, bottom, right);
+		}
+
+		@Override
+		public double getTop() {
+			return top;
+		}
+
+		@Override
+		public double getLeft() {
+			return left;
+		}
+
+		@Override
+		public double getBottom() {
+			return bottom;
+		}
+
+		@Override
+		public double getRight() {
+			return right;
+		}
+
+		@Override
+		public void setInsets(Insets2D insets) {
+			if (insets == null) {
+				return;
+			}
+			setInsets(insets.getTop(), insets.getLeft(),
+					insets.getBottom(), insets.getRight());
+		}
+
+		@Override
+		public void setInsets(double top, double left,
+				double bottom, double right) {
+			this.top = top;
+			this.left = left;
+			this.bottom = bottom;
+			this.right = right;
+		}
+
+		@Override
+		public String toString() {
+			return String.format(Locale.US,
+				"%s[top=%f, left=%f, bottom=%f, right=%f]", //$NON-NLS-1$
+				getClass().getName(), top, left, bottom, right);
+		}
+
+		@Override
+		public boolean equals(Object obj) {
+			if (!(obj instanceof Insets2D)) {
+				return false;
+			}
+			Insets2D insets = (Insets2D) obj;
+			return (getTop() == insets.getTop())
+				&& (getLeft() == insets.getLeft())
+				&& (getBottom() == insets.getBottom())
+				&& (getRight() == insets.getRight());
+		}
+
+		@Override
+		public int hashCode() {
+			long bits = java.lang.Double.doubleToLongBits(getTop());
+			bits += java.lang.Double.doubleToLongBits(getLeft()) * 37;
+			bits += java.lang.Double.doubleToLongBits(getBottom()) * 43;
+			bits += java.lang.Double.doubleToLongBits(getRight()) * 47;
+			return ((int) bits) ^ ((int) (bits >> 32));
+		}
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Label.java

@@ -0,0 +1,409 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.util.Objects;
+
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+
+/**
+ * Class that draws a label to a specific location.
+ * A Label is able to manage its settings and to set and get the
+ * displayed text, as well as calculating its bounds.
+ */
+public class Label extends AbstractDrawable {
+
+	/** Text for this label. */
+	private String text;
+	/** Horizontal label alignment. */
+	private double alignmentX;
+	/** Vertical label alignment. */
+	private double alignmentY;
+	/** Font used to display the text of this label. */
+	private Font font;
+	/** Rotation angle in degrees. */
+	private double rotation;
+	/** Paint used to draw the shape. */
+	private Paint color;
+	/** Relative text alignment. */
+	private double textAlignment;
+	/** Decides whether the text should be wrapped. */
+	private boolean wordWrapEnabled;
+	/** Paint used to display the background. */
+	private Paint background;
+
+	/** Cached outline of the label text with word wrapping. */
+	private transient Shape outlineWrapped;
+	/** Cached outline of the label text without word wrapping. */
+	private transient Shape outlineUnwrapped;
+
+	/**
+	 * Initializes a new empty {@code Label} instance.
+	 */
+	public Label() {
+		this(""); //$NON-NLS-1$
+	}
+
+	/**
+	 * Initializes a new {@code Label} instance with the specified text.
+	 * @param text Text to be displayed.
+	 */
+	public Label(String text) {
+		this.text = text;
+
+		alignmentX = 0.5;
+		alignmentY = 0.5;
+		font = Font.decode(null);
+		rotation = 0.0;
+		color = Color.BLACK;
+		textAlignment = 0.5;
+		wordWrapEnabled = false;
+	}
+
+	/**
+	 * Draws the object with the specified drawing context.
+	 * @param context Environment used for drawing
+	 */
+	public void draw(DrawingContext context) {
+		boolean wordWrap = isWordWrapEnabled();
+		Shape labelShape = getCachedOutline(wordWrap);
+
+		if (labelShape == null) {
+			return;
+		}
+
+		Rectangle2D textBounds = labelShape.getBounds2D();
+
+		// Rotate label text around its center point
+		double rotation = getRotation();
+		if (MathUtils.isCalculatable(rotation) && rotation != 0.0) {
+			AffineTransform txLabelText =
+				AffineTransform.getRotateInstance(
+					Math.toRadians(-rotation),
+					textBounds.getCenterX(),
+					textBounds.getCenterY()
+				);
+			labelShape = txLabelText.createTransformedShape(labelShape);
+			textBounds = labelShape.getBounds2D();
+		}
+
+		// Get graphics instance and store state information
+		Graphics2D graphics = context.getGraphics();
+		AffineTransform txOld = graphics.getTransform();
+
+		// Draw background
+		Paint background = getBackground();
+		if (background != null) {
+			GraphicsUtils.fillPaintedShape(graphics, getBounds(), background, null);
+		}
+
+		// Calculate absolute text position:
+		// First, move the text to the upper left of the bounding rectangle
+		double shapePosX = getX() - textBounds.getX();
+		double shapePosY = getY() - textBounds.getY();
+		// Position the text inside the bounding rectangle using the alignment
+		// settings
+		double alignmentX = getAlignmentX();
+		double alignmentY = getAlignmentY();
+		shapePosX += alignmentX*(getWidth() - textBounds.getWidth());
+		shapePosY += alignmentY*(getHeight() - textBounds.getHeight());
+		// Apply positioning
+		graphics.translate(shapePosX, shapePosY);
+
+		// Paint the shape with the color from settings
+		Paint paint = getColor();
+		GraphicsUtils.fillPaintedShape(graphics, labelShape, paint, null);
+
+
+		// Restore previous state
+		graphics.setTransform(txOld);
+	}
+
+	@Override
+	public Dimension2D getPreferredSize() {
+		Dimension2D d = super.getPreferredSize();
+		if (getCachedOutline(false) != null) {
+			Shape shape = getTextRectangle();
+			Rectangle2D bounds = shape.getBounds2D();
+			double rotation = getRotation();
+			if (MathUtils.isCalculatable(rotation) && rotation != 0.0) {
+				AffineTransform txLabelText =
+					AffineTransform.getRotateInstance(
+						Math.toRadians(-rotation),
+						bounds.getCenterX(),
+						bounds.getCenterY()
+					);
+				shape = txLabelText.createTransformedShape(shape);
+			}
+			d.setSize(
+				shape.getBounds2D().getWidth(),
+				shape.getBounds2D().getHeight()
+			);
+		}
+		return d;
+	}
+
+	/**
+	 * Returns an outline shape for this label.
+	 * @param wordWrap Wrap the words of the text to fit the current size.
+	 * @return Outline for this label.
+	 */
+	protected Shape getOutline(boolean wordWrap) {
+		Font font = getFont();
+		float wrappingWidth = 0f;
+		if (wordWrap) {
+			double rotation = Math.toRadians(getRotation());
+			wrappingWidth = (float) (
+				Math.abs(Math.cos(rotation))*getWidth() +
+				Math.abs(Math.sin(rotation))*getHeight());
+		}
+		double alignment = getTextAlignment();
+		return GraphicsUtils.getOutline(
+			getText(), font, wrappingWidth, alignment);
+	}
+
+	/**
+	 * Returns a cached instance of the outline shape for this label.
+	 * @param wordWrap Flag, whether to wrap lines to fit the current size.
+	 * @return An instance of the outline shape for this label.
+	 */
+	protected Shape getCachedOutline(boolean wordWrap) {
+		if (!isValid() && getText() != null && !getText().isEmpty()) {
+			outlineWrapped = getOutline(true);
+			outlineUnwrapped = getOutline(false);
+		}
+		if (wordWrap) {
+			return outlineWrapped;
+		} else {
+			return outlineUnwrapped;
+		}
+	}
+
+	/**
+	 * Returns the bounding rectangle of the text without rotation or word
+	 * wrapping.
+	 * @return Bounding rectangle.
+	 */
+	public Rectangle2D getTextRectangle() {
+		return getCachedOutline(false).getBounds();
+	}
+
+	/**
+	 * Returns the text of this label.
+	 * @return Text.
+	 */
+	public String getText() {
+		return text;
+	}
+
+	/**
+	 * Sets the displayed text to the specified value.
+	 * @param text Text to be displayed.
+	 */
+	public void setText(String text) {
+		this.text = text;
+		invalidate();
+	}
+
+	/**
+	 * Marks the text layout as invalid. It has to be refreshed the next time.
+	 */
+	protected void invalidate() {
+		outlineWrapped = null;
+		outlineUnwrapped = null;
+	}
+
+	/**
+	 * Returns whether the cached values in this label are valid.
+	 * @return {@code true} if all cached values are valid,
+	 *         otherwise {@code false}.
+	 */
+	protected boolean isValid() {
+		boolean wordWrap = isWordWrapEnabled();
+		if (wordWrap) {
+			return outlineWrapped != null;
+		} else {
+			return outlineUnwrapped != null;
+		}
+	}
+
+	@Override
+	public void setBounds(double x, double y, double width, double height) {
+		double widthOld = getWidth();
+		double heightOld = getHeight();
+		super.setBounds(x, y, width, height);
+		if (width != widthOld || height != heightOld) {
+			invalidate();
+		}
+	}
+
+	/**
+	 * Returns the horizontal alignment within the bounding rectangle.
+	 * 0.0 means left, 1.0 means right.
+	 * @return Horizontal label alignment.
+	 */
+	public double getAlignmentX() {
+		return alignmentX;
+	}
+
+	/**
+	 * Sets the horizontal alignment within the bounding rectangle.
+	 * 0.0 means left, 1.0 means right.
+	 * @param alignmentX Horizontal label alignment.
+	 */
+	public void setAlignmentX(double alignmentX) {
+		this.alignmentX = alignmentX;
+	}
+
+	/**
+	 * Returns the vertical alignment within the bounding rectangle.
+	 * 0.0 means top, 1.0 means bottom.
+	 * @return Vertical label alignment.
+	 */
+	public double getAlignmentY() {
+		return alignmentY;
+	}
+
+	/**
+	 * Sets the vertical alignment within the bounding rectangle.
+	 * 0.0 means top, 1.0 means bottom.
+	 * @param alignmentY Vertical label alignment.
+	 */
+	public void setAlignmentY(double alignmentY) {
+		this.alignmentY = alignmentY;
+	}
+
+	/**
+	 * Returns the font used to display the text of this label.
+	 * @return Font used for text display.
+	 */
+	public Font getFont() {
+		return font;
+	}
+
+	/**
+	 * Sets the font used to display the text of this label.
+	 * @param font Font used for text display.
+	 */
+	public void setFont(Font font) {
+		this.font = font;
+		invalidate();
+	}
+
+	/**
+	 * Returns the rotation of this label.
+	 * The rotation will be counterclockwise.
+	 * @return Rotation in degrees.
+	 */
+	public double getRotation() {
+		return rotation;
+	}
+
+	/**
+	 * Sets the rotation of this label.
+	 * The rotation will be counterclockwise.
+	 * @param angle Rotation in degrees.
+	 */
+	public void setRotation(double angle) {
+		this.rotation = angle;
+		invalidate();
+	}
+
+	/**
+	 * Returns the paint used to draw the label shape.
+	 * @return Paint for shape drawing.
+	 */
+	public Paint getColor() {
+		return color;
+	}
+
+	/**
+	 * Sets the paint used to draw the label shape.
+	 * @param color Paint for shape drawing.
+	 */
+	public void setColor(Paint color) {
+		this.color = color;
+	}
+
+	/**
+	 * Returns the alignment of text with multiple lines.
+	 * 0.0 means left, 1.0 means right.
+	 * @return Relative text alignment.
+	 */
+	public double getTextAlignment() {
+		return textAlignment;
+	}
+
+	/**
+	 * Sets the alignment of text with multiple lines.
+	 * 0.0 means left, 1.0 means right.
+	 * @param textAlignment Relative text alignment.
+	 */
+	public void setTextAlignment(double textAlignment) {
+		this.textAlignment = textAlignment;
+		invalidate();
+	}
+
+	/**
+	 * Returns whether words of the text should be wrapped to fit the size of the label.
+	 * @return {@code true} if the text should be wrapped, {@code false} otherwise.
+	 */
+	public boolean isWordWrapEnabled() {
+		return wordWrapEnabled;
+	}
+
+	/**
+	 * Sets whether words of the text should be wrapped to fit the size of the label.
+	 * @param wordWrapEnabled {@code true} if the text should be wrapped, {@code false} otherwise.
+	 */
+	public void setWordWrapEnabled(boolean wordWrapEnabled) {
+		this.wordWrapEnabled = wordWrapEnabled;
+		invalidate();
+	}
+
+	/**
+	 * Returns the background color.
+	 * @return Background color or {@code null}, if no background is defined.
+	 */
+	public Paint getBackground() {
+		return background;
+	}
+
+	/**
+	 * Sets the background color to the specified value.
+	 * @param background Background color.
+	 */
+	public void setBackground(Paint background) {
+		this.background = background;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (!(obj instanceof Label)) {
+			return false;
+		}
+		Label label = (Label) obj;
+		return ((getText() == null && label.getText() == null) || getText().equals(label.getText()))
+				&& (getAlignmentX() == label.getAlignmentX())
+				&& (getAlignmentY() == label.getAlignmentY())
+				&& ((getFont() == null && label.getFont() == null) || getFont().equals(label.getFont()))
+				&& (getRotation() == label.getRotation())
+				&& ((getColor() == null && label.getColor() == null) || getColor().equals(label.getColor()))
+				&& (getTextAlignment() == label.getTextAlignment())
+				&& (isWordWrapEnabled() == label.isWordWrapEnabled())
+				&& ((getBackground() == null && label.getBackground() == null) || getBackground().equals(label.getBackground()));
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(text, alignmentX, alignmentY, font, rotation, color, textAlignment, wordWrapEnabled, background);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Location.java

@@ -0,0 +1,55 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+/**
+ * Indicates the location of components.
+ */
+public enum Location {
+	/** Central location. */
+	CENTER(0.5, 0.5),
+	/** Northern location. */
+	NORTH(0.5, 0.0),
+	/** North-eastern location. */
+	NORTH_EAST(1.0, 0.0),
+	/** Eastern location. */
+	EAST(1.0, 0.5),
+	/** South-eastern location. */
+	SOUTH_EAST(1.0, 1.0),
+	/** Southern location. */
+	SOUTH(0.5, 1.0),
+	/** South-western location. */
+	SOUTH_WEST(0.0, 1.0),
+	/** Western location. */
+	WEST(0.0,  0.5),
+	/** North-western location. */
+	NORTH_WEST(0.0, 0.0);
+
+	/** Horizontal alignment. */
+	private final double alignH;
+	/** Vertical alignment. */
+	private final double alignV;
+
+	/**
+	 * Constructor that initializes a new location.
+	 * @param alignH Horizontal alignment.
+	 * @param alignV Vertical alignment.
+	 */
+	Location(double alignH, double alignV) {
+		this.alignH = alignH;
+		this.alignV = alignV;
+	}
+
+	/**
+	 * Returns the horizontal alignment as a double value.
+	 * @return horizontal alignment
+	 */
+	public double getAlignmentH() {
+		return alignH;
+	}
+	/**
+	 * Returns the vertical alignment as a double value.
+	 * @return vertical alignment
+	 */
+	public double getAlignmentV() {
+		return alignV;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/Orientation.java

@@ -0,0 +1,11 @@
+package org.xbib.graphics.graph.gral.graphics;
+
+/**
+ * Enumeration type to describe the orientation of a arbitrary elements.
+ */
+public enum Orientation {
+	/** Horizontal orientation. */
+	HORIZONTAL,
+	/** Vertical orientation. */
+	VERTICAL
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/AbstractLayout.java

@@ -0,0 +1,34 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+public abstract class AbstractLayout implements Layout {
+
+	/** Horizontal spacing of components. */
+	private double gapX;
+	/** Vertical spacing of components. */
+	private double gapY;
+
+	public AbstractLayout(double gapX, double gapY) {
+		this.gapX = gapX;
+		this.gapY = gapY;
+	}
+
+	@Override
+	public double getGapX() {
+		return gapX;
+	}
+
+	@Override
+	public void setGapX(double gapX) {
+		this.gapX = gapX;
+	}
+
+	@Override
+	public double getGapY() {
+		return gapY;
+	}
+
+	@Override
+	public void setGapY(double gapY) {
+		this.gapY = gapY;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/AbstractOrientedLayout.java

@@ -0,0 +1,24 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import org.xbib.graphics.graph.gral.graphics.Orientation;
+
+public abstract class AbstractOrientedLayout extends AbstractLayout implements
+		OrientedLayout {
+	/** Orientation in which elements should be laid out. */
+	private Orientation orientation;
+
+	public AbstractOrientedLayout(Orientation orientation, double gapX, double gapY) {
+		super(gapX, gapY);
+		this.orientation = orientation;
+	}
+
+	@Override
+	public Orientation getOrientation() {
+		return orientation;
+	}
+
+	@Override
+	public void setOrientation(Orientation orientation) {
+		this.orientation = orientation;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/EdgeLayout.java

@@ -0,0 +1,257 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Insets2D;
+import org.xbib.graphics.graph.gral.graphics.Location;
+
+/**
+ * Implementation of Layout that arranges a {@link Container}'s components
+ * according to a certain grid. This is similar to Java's
+ * {@link java.awt.BorderLayout}, but also allows components to be placed in
+ * each of the corners.
+ */
+public class EdgeLayout extends AbstractLayout {
+
+	/**
+	 * Initializes a layout manager object with the specified space between the
+	 * components.
+	 * @param gapH Horizontal gap.
+	 * @param gapV Vertical gap.
+	 */
+	public EdgeLayout(double gapH, double gapV) {
+		super(gapH, gapV);
+	}
+
+	/**
+	 * Initializes a layout manager object without space between the
+	 * components.
+	 */
+	public EdgeLayout() {
+		this(0.0, 0.0);
+	}
+
+	/**
+	 * Arranges the components of the specified container according to this
+	 * layout.
+	 * @param container Container to be laid out.
+	 */
+	public void layout(Container container) {
+		// Fetch components
+		Map<Location, Drawable> comps = getComponentsByLocation(container);
+		Drawable north = comps.get(Location.NORTH);
+		Drawable northEast = comps.get(Location.NORTH_EAST);
+		Drawable east = comps.get(Location.EAST);
+		Drawable southEast = comps.get(Location.SOUTH_EAST);
+		Drawable south = comps.get(Location.SOUTH);
+		Drawable southWest = comps.get(Location.SOUTH_WEST);
+		Drawable west = comps.get(Location.WEST);
+		Drawable northWest = comps.get(Location.NORTH_WEST);
+		Drawable center = comps.get(Location.CENTER);
+
+		// Calculate maximum widths and heights
+		double widthWest   = getMaxWidth(northWest,  west,   southWest);
+		double widthEast   = getMaxWidth(northEast,  east,   southEast);
+		double heightNorth = getMaxHeight(northWest, north,  northEast);
+		double heightSouth = getMaxHeight(southWest, south,  southEast);
+
+		double gapWest  = (widthWest > 0.0 && center != null) ? getGapX() : 0.0;
+		double gapEast  = (widthEast > 0.0 && center != null) ? getGapX() : 0.0;
+		double gapNorth = (heightNorth > 0.0 && center != null) ? getGapY() : 0.0;
+		double gapSouth = (heightSouth > 0.0 && center != null) ? getGapY() : 0.0;
+
+		Rectangle2D bounds = container.getBounds();
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+
+		double xWest   = bounds.getMinX() + insets.getLeft();
+		double xCenter = xWest + widthWest + gapWest;
+		double xEast   = bounds.getMaxX() - insets.getRight() - widthEast;
+		double yNorth  = bounds.getMinY() + insets.getTop();
+		double yCenter = yNorth + heightNorth + gapNorth;
+		double ySouth  = bounds.getMaxY() - insets.getBottom() - heightSouth;
+
+		double widthAll = widthWest + widthEast;
+		double heightAll = heightNorth + heightSouth;
+		double gapHAll = gapWest + gapEast;
+		double gapVAll = gapNorth - gapSouth;
+
+		layoutComponent(northWest,
+			xWest, yNorth,
+			widthWest, heightNorth
+		);
+
+		layoutComponent(north,
+			xCenter, yNorth,
+			bounds.getWidth() - insets.getHorizontal() - widthAll - gapHAll,
+			heightNorth
+		);
+
+		layoutComponent(northEast,
+			xEast, yNorth,
+			widthEast, heightNorth
+		);
+
+		layoutComponent(east,
+			xEast, yCenter,
+			widthEast,
+			bounds.getHeight() - insets.getVertical() - heightAll - gapVAll
+		);
+
+		layoutComponent(southEast,
+			xEast, ySouth,
+			widthEast,
+			heightSouth
+		);
+
+		layoutComponent(south,
+			xCenter, ySouth,
+			bounds.getWidth() - insets.getHorizontal() - widthAll - gapHAll,
+			heightSouth
+		);
+
+		layoutComponent(southWest,
+			xWest, ySouth,
+			widthWest,
+			heightSouth
+		);
+
+		layoutComponent(west,
+			xWest, yCenter,
+			widthWest,
+			bounds.getHeight() - insets.getVertical() - heightAll - gapVAll
+		);
+
+		layoutComponent(center,
+			xCenter, yCenter,
+				bounds.getWidth()
+					- insets.getLeft() - widthAll
+					- insets.getRight() - gapHAll,
+				bounds.getHeight()
+					- insets.getTop() - heightAll
+					- insets.getBottom() - gapVAll
+		);
+	}
+
+	/**
+	 * Returns the preferred size of the specified container using this layout.
+	 * @param container Container whose preferred size is to be returned.
+	 * @return Preferred extent of the specified container.
+	 */
+	public Dimension2D getPreferredSize(Container container) {
+		// Fetch components
+		Map<Location, Drawable> comps = getComponentsByLocation(container);
+		Drawable north = comps.get(Location.NORTH);
+		Drawable northEast = comps.get(Location.NORTH_EAST);
+		Drawable east = comps.get(Location.EAST);
+		Drawable southEast = comps.get(Location.SOUTH_EAST);
+		Drawable south = comps.get(Location.SOUTH);
+		Drawable southWest = comps.get(Location.SOUTH_WEST);
+		Drawable west = comps.get(Location.WEST);
+		Drawable northWest = comps.get(Location.NORTH_WEST);
+		Drawable center = comps.get(Location.CENTER);
+
+		// Calculate maximum widths and heights
+		double widthWest    = getMaxWidth(northWest,  west,   southWest);
+		double widthCenter  = getMaxWidth(north,      center, south);
+		double widthEast    = getMaxWidth(northEast,  east,   southEast);
+		double heightNorth  = getMaxHeight(northWest, north,  northEast);
+		double heightCenter = getMaxHeight(west,      center, east);
+		double heightSouth  = getMaxHeight(southWest, south,  southEast);
+
+		double gapEast  = (widthEast > 0.0 && center != null) ? getGapX() : 0.0;
+		double gapWest  = (widthWest > 0.0 && center != null) ? getGapX() : 0.0;
+		double gapNorth = (heightNorth > 0.0 && center != null) ? getGapY() : 0.0;
+		double gapSouth = (heightSouth > 0.0 && center != null) ? getGapY() : 0.0;
+
+		// Calculate preferred dimensions
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+		double width = insets.getLeft() + widthEast + gapEast + widthCenter +
+			gapWest + widthWest + insets.getRight();
+		double height = insets.getTop() + heightNorth + gapNorth + heightCenter +
+			gapSouth + heightSouth + insets.getBottom();
+
+		return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(
+			width, height
+		);
+	}
+
+	/**
+	 * Returns a map all components which are stored with a {@code Location}
+	 * constraint in the specified container.
+	 * @param container Container which stores the components
+	 * @return A map of all components (values) and their constraints (keys) in
+	 *         the specified container.
+	 */
+	private static Map<Location, Drawable> getComponentsByLocation(Container container) {
+		Map<Location, Drawable> drawablesByLocation = new HashMap<>();
+		for (Drawable d: container) {
+			Object constraints = container.getConstraints(d);
+			if (constraints instanceof Location) {
+				drawablesByLocation.put((Location) constraints, d);
+			}
+		}
+		return drawablesByLocation;
+	}
+
+	/**
+	 * Returns the maximum width of an array of Drawables.
+	 * @param drawables Drawables to be measured.
+	 * @return Maximum horizontal extent.
+	 */
+	private static double getMaxWidth(Drawable... drawables) {
+		double width = 0.0;
+		for (Drawable d : drawables) {
+			if (d == null) {
+				continue;
+			}
+			width = Math.max(width, d.getPreferredSize().getWidth());
+		}
+
+		return width;
+	}
+
+	/**
+	 * Returns the maximum height of an array of Drawables.
+	 * @param drawables Drawables to be measured.
+	 * @return Maximum vertical extent.
+	 */
+	private static double getMaxHeight(Drawable... drawables) {
+		double height = 0.0;
+		for (Drawable d : drawables) {
+			if (d == null) {
+				continue;
+			}
+			height = Math.max(height, d.getPreferredSize().getHeight());
+		}
+
+		return height;
+	}
+
+	/**
+	 * Sets the bounds of the specified {@code Drawable} to the specified
+	 * values.
+	 * @param component {@code Drawable} that should be resized.
+	 * @param x X coordinate.
+	 * @param y Y coordinate.
+	 * @param w Width.
+	 * @param h Height.
+	 */
+	private static void layoutComponent(Drawable component,
+			double x, double y, double w, double h) {
+		if (component == null) {
+			return;
+		}
+		component.setBounds(x, y, w, h);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/Layout.java

@@ -0,0 +1,51 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import java.awt.geom.Dimension2D;
+
+import org.xbib.graphics.graph.gral.graphics.Container;
+
+/**
+ * Interface that provides basic functions for arranging a layout.
+ * Functionality includes the arrangement of components and returning the
+ * preferred size of a specified container using this layout.
+ */
+public interface Layout {
+
+	/**
+	 * Returns the amount of horizontal space between two layed out components.
+	 * @return Space in pixels.
+	 */
+	double getGapX();
+
+	/**
+	 * Sets the amount of horizontal space between two layed out components.
+	 * @param gapX Space in pixels.
+	 */
+	void setGapX(double gapX);
+
+	/**
+	 * Returns the amount of vertical space between two layed out components.
+	 * @return Space in pixels.
+	 */
+	double getGapY();
+
+	/**
+	 * Sets the amount of horizontal space between two layed out components.
+	 * @param gapY Space in pixels.
+	 */
+	void setGapY(double gapY);
+
+	/**
+	 * Arranges the components of the specified container according to this
+	 * layout.
+	 * @param container Container to be laid out.
+	 */
+	void layout(Container container);
+
+	/**
+	 * Returns the preferred size of the specified container using this layout.
+	 * @param container Container whose preferred size is to be returned.
+	 * @return Preferred extent of the specified container.
+	 */
+	Dimension2D getPreferredSize(Container container);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/OrientedLayout.java

@@ -0,0 +1,21 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import org.xbib.graphics.graph.gral.graphics.Orientation;
+
+/**
+ * Represents a layout with a specific orientation.
+ * @see Orientation
+ */
+public interface OrientedLayout extends Layout {
+	/**
+	 * Returns the layout direction.
+	 * @return Layout orientation.
+	 */
+	Orientation getOrientation();
+
+	/**
+	 * Sets the layout direction.
+	 * @param orientation Layout orientation.
+	 */
+	void setOrientation(Orientation orientation);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/OuterEdgeLayout.java

@@ -0,0 +1,226 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Insets2D;
+import org.xbib.graphics.graph.gral.graphics.Location;
+
+/**
+ * Implementation of Layout that arranges a {@link Container}'s components
+ * inside or in the regions outside of the container. This is similar to
+ * {@link EdgeLayout}, but also allows components to be placed outside the
+ * container.
+ */
+public class OuterEdgeLayout extends AbstractLayout {
+
+	/**
+	 * Initializes a layout manager object with the specified space between the
+	 * container's edges and the components.
+	 * @param gap Spacing between the container's edges and the components.
+	 */
+	public OuterEdgeLayout(double gap) {
+		super(gap, gap);
+	}
+
+	/**
+	 * Initializes a layout manager object without space between the
+	 * components.
+	 */
+	public OuterEdgeLayout() {
+		this(0.0);
+	}
+
+	/**
+	 * Arranges the components of the specified container according to this
+	 * layout.
+	 * @param container Container to be laid out.
+	 */
+	public void layout(Container container) {
+		// Fetch components
+		Map<Location, Drawable> comps = getComponentsByLocation(container);
+		Drawable north = comps.get(Location.NORTH);
+		Drawable northEast = comps.get(Location.NORTH_EAST);
+		Drawable east = comps.get(Location.EAST);
+		Drawable southEast = comps.get(Location.SOUTH_EAST);
+		Drawable south = comps.get(Location.SOUTH);
+		Drawable southWest = comps.get(Location.SOUTH_WEST);
+		Drawable west = comps.get(Location.WEST);
+		Drawable northWest = comps.get(Location.NORTH_WEST);
+		Drawable center = comps.get(Location.CENTER);
+
+		// Calculate maximum widths and heights
+		double widthWest   = getMaxWidth(northWest,  west,   southWest);
+		double widthEast   = getMaxWidth(northEast,  east,   southEast);
+		double heightNorth = getMaxHeight(northWest, north,  northEast);
+		double heightSouth = getMaxHeight(southWest, south,  southEast);
+
+		double gapEast  = (widthEast > 0.0) ? getGapX() : 0.0;
+		double gapWest  = (widthWest > 0.0) ? getGapX() : 0.0;
+		double gapNorth = (heightNorth > 0.0) ? getGapY() : 0.0;
+		double gapSouth = (heightSouth > 0.0) ? getGapY() : 0.0;
+
+		Rectangle2D bounds = container.getBounds();
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+
+		double xWest   = bounds.getMinX() + insets.getLeft() - gapWest - widthWest;
+		double xCenter = bounds.getMinX() + insets.getLeft();
+		double xEast   = bounds.getMaxX() - insets.getRight() + gapEast;
+		double yNorth  = bounds.getMinY() + insets.getTop() - gapNorth - heightNorth;
+		double yCenter = bounds.getMinY() + insets.getTop();
+		double ySouth  = bounds.getMaxY() - insets.getBottom() + gapSouth;
+
+		layoutComponent(northWest,
+			xWest, yNorth,
+			widthWest, heightNorth
+		);
+
+		layoutComponent(north,
+			xCenter, yNorth,
+			bounds.getWidth() - insets.getHorizontal(),
+			heightNorth
+		);
+
+		layoutComponent(northEast,
+			xEast, yNorth,
+			widthEast, heightNorth
+		);
+
+		layoutComponent(east,
+			xEast, yCenter,
+			widthEast,
+			bounds.getHeight() - insets.getVertical()
+		);
+
+		layoutComponent(southEast,
+			xEast, ySouth,
+			widthEast,
+			heightSouth
+		);
+
+		layoutComponent(south,
+			xCenter, ySouth,
+			bounds.getWidth() - insets.getHorizontal(),
+			heightSouth
+		);
+
+		layoutComponent(southWest,
+			xWest, ySouth,
+			widthWest,
+			heightSouth
+		);
+
+		layoutComponent(west,
+			xWest, yCenter,
+			widthWest,
+			bounds.getHeight() - insets.getVertical()
+		);
+
+		layoutComponent(center,
+			xCenter + getGapX(), yCenter + getGapY(),
+				bounds.getWidth() - insets.getHorizontal() - 2*getGapX(),
+				bounds.getHeight() - insets.getVertical() - 2*getGapY()
+		);
+	}
+
+	/**
+	 * Returns the preferred size of the specified container using this layout.
+	 * @param container Container whose preferred size is to be returned.
+	 * @return Preferred extent of the specified container.
+	 */
+	public Dimension2D getPreferredSize(Container container) {
+		// Fetch components
+		Map<Location, Drawable> comps = getComponentsByLocation(container);
+		Drawable center = comps.get(Location.CENTER);
+
+
+		// Calculate preferred dimensions
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+
+		double width = center.getWidth() + insets.getHorizontal() + 2*getGapX();
+		double height = center.getHeight() + insets.getVertical() + 2*getGapY();
+
+		return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(
+			width, height
+		);
+	}
+
+	/**
+	 * Returns a map all components which are stored with a {@code Location}
+	 * constraint in the specified container.
+	 * @param container Container which stores the components
+	 * @return A map of all components (values) and their constraints (keys) in
+	 *         the specified container.
+	 */
+	private static Map<Location, Drawable> getComponentsByLocation(Container container) {
+		Map<Location, Drawable> drawablesByLocation = new HashMap<>();
+		for (Drawable d: container) {
+			Object constraints = container.getConstraints(d);
+			if (constraints instanceof Location) {
+				drawablesByLocation.put((Location) constraints, d);
+			}
+		}
+		return drawablesByLocation;
+	}
+
+	/**
+	 * Returns the maximum width of an array of Drawables.
+	 * @param drawables Drawables to be measured.
+	 * @return Maximum horizontal extent.
+	 */
+	private static double getMaxWidth(Drawable... drawables) {
+		double width = 0.0;
+		for (Drawable d : drawables) {
+			if (d == null) {
+				continue;
+			}
+			width = Math.max(width, d.getPreferredSize().getWidth());
+		}
+
+		return width;
+	}
+
+	/**
+	 * Returns the maximum height of an array of Drawables.
+	 * @param drawables Drawables to be measured.
+	 * @return Maximum vertical extent.
+	 */
+	private static double getMaxHeight(Drawable... drawables) {
+		double height = 0.0;
+		for (Drawable d : drawables) {
+			if (d == null) {
+				continue;
+			}
+			height = Math.max(height, d.getPreferredSize().getHeight());
+		}
+
+		return height;
+	}
+
+	/**
+	 * Sets the bounds of the specified {@code Drawable} to the specified
+	 * values.
+	 * @param component {@code Drawable} that should be resized.
+	 * @param x X coordinate.
+	 * @param y Y coordinate.
+	 * @param w Width.
+	 * @param h Height.
+	 */
+	private static void layoutComponent(Drawable component,
+			double x, double y, double w, double h) {
+		if (component == null) {
+			return;
+		}
+		component.setBounds(x, y, w, h);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/StackedLayout.java

@@ -0,0 +1,192 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.io.Serializable;
+
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Insets2D;
+import org.xbib.graphics.graph.gral.graphics.Orientation;
+
+/**
+ * Class that represents a layout manager which arranges its components
+ * as horizontal or vertical stacks.
+ */
+public class StackedLayout extends AbstractOrientedLayout {
+
+	/** Default layout behaviour for components. */
+	private final Constraints defaultConstraints;
+
+	public static class Constraints {
+		/**
+		 * Whether the component is stretched to the container's width (vertical layout)
+		 * or height (horizontal layout).
+		 */
+		private final boolean stretched;
+		/** Horizontal alignment of the component. */
+		private final double alignmentX;
+		/** Vertical alignment of the component. */
+		private final double alignmentY;
+
+		public Constraints(boolean stretched, double alignmentX, double alignmentY) {
+			this.stretched = stretched;
+			this.alignmentX = alignmentX;
+			this.alignmentY = alignmentY;
+		}
+
+		/**
+		 * Returns whether the component is stretched to the container's width (vertical layout)
+		 * or height (horizontal orientation).
+		 * @return {@code true} if the layed out component should be stretched, {@code false} otherwise.
+		 */
+		public boolean isStretched() {
+			return stretched;
+		}
+
+		/**
+		 * Returns the relative horizontal position of the component within the container.
+		 * This value only has effect, if the components do not fill the width of the container.
+		 * @return Relative position of layed out components.
+		 */
+		public double getAlignmentX() {
+			return alignmentX;
+		}
+
+		/**
+		 * Returns the relative vertical position of the components within the container.
+		 * This value only has effect, if the components do not fill the height of the container.
+		 * @return Relative position of layed out components.
+		 */
+		public double getAlignmentY() {
+			return alignmentY;
+		}
+	}
+
+	/**
+	 * Creates a new StackedLayout object with the specified orientation
+	 * and default gap between the components.
+	 * @param orientation Orientation in which components are stacked.
+	 */
+	public StackedLayout(Orientation orientation) {
+		this(orientation, 0.0, 0.0);
+	}
+
+	/**
+	 * Creates a new StackedLayout object with the specified orientation
+	 * and gap between the components.
+	 * @param orientation Orientation in which components are stacked.
+	 * @param gapX Horizontal gap between the components.
+	 * @param gapY Vertical gap between the components.
+	 */
+	public StackedLayout(Orientation orientation, double gapX, double gapY) {
+		super(orientation, gapX, gapY);
+		defaultConstraints = new Constraints(true, 0.5, 0.5);
+	}
+
+	/**
+	 * Arranges the components of the specified container according to this
+	 * layout.
+	 * @param container Container to be laid out.
+	 */
+	public void layout(Container container) {
+		Dimension2D size = getPreferredSize(container);
+		Rectangle2D bounds = container.getBounds();
+		Insets2D insets = container.getInsets();
+
+		double xMin = bounds.getMinX() + insets.getLeft();
+		double yMin = bounds.getMinY() + insets.getTop();
+		double width = bounds.getWidth() - insets.getLeft() - insets.getRight();
+		double height = bounds.getHeight() - insets.getTop() - insets.getBottom();
+		int count = 0;
+		if (getOrientation() == Orientation.HORIZONTAL) {
+			xMin += Math.max(bounds.getWidth() - size.getWidth(), 0.0)*defaultConstraints.getAlignmentX();
+			for (Drawable component : container) {
+				if (count++ > 0) {
+					xMin += getGapX();
+				}
+				Dimension2D compBounds = component.getPreferredSize();
+				Constraints constraints = getConstraints(component, container);
+				double componentHeight;
+				double componentY;
+				if (constraints.isStretched()) {
+					componentHeight = height;
+					componentY = yMin;
+				} else {
+					componentHeight = Math.min(compBounds.getHeight(), height);
+					componentY = yMin + (height - componentHeight)*constraints.getAlignmentY();
+				}
+				component.setBounds(xMin, componentY, compBounds.getWidth(), componentHeight);
+				xMin += compBounds.getWidth();
+			}
+		} else if (getOrientation() == Orientation.VERTICAL) {
+			yMin += Math.max(bounds.getHeight() - size.getHeight(), 0.0)*defaultConstraints.getAlignmentY();
+			for (Drawable component : container) {
+				if (count++ > 0) {
+					yMin += getGapY();
+				}
+				Dimension2D compBounds = component.getPreferredSize();
+				Constraints constraints = getConstraints(component, container);
+				double componentWidth;
+				double componentX;
+				if (constraints.isStretched()) {
+					componentWidth = width;
+					componentX = xMin;
+				} else {
+					componentWidth = Math.min(compBounds.getWidth(), width);
+					componentX = xMin + (width - componentWidth)*constraints.getAlignmentX();
+				}
+				component.setBounds(componentX, yMin, componentWidth, compBounds.getHeight());
+				yMin += compBounds.getHeight();
+			}
+		}
+	}
+
+	/**
+	 * Returns the preferred size of the specified container using this layout.
+	 * @param container Container whose preferred size is to be returned.
+	 * @return Preferred extent of the specified container.
+	 */
+	public Dimension2D getPreferredSize(Container container) {
+		Insets2D insets = container.getInsets();
+
+		double width = insets.getLeft();
+		double height = insets.getTop();
+		int count = 0;
+		if (getOrientation() == Orientation.HORIZONTAL) {
+			double h = 0.0;
+			for (Drawable component : container) {
+				if (count++ > 0) {
+					width += getGapX();
+				}
+				Dimension2D itemBounds = component.getPreferredSize();
+				width += itemBounds.getWidth();
+				h = Math.max(height, itemBounds.getHeight());
+			}
+			height += h;
+		} else if (getOrientation() == Orientation.VERTICAL) {
+			double w = 0.0;
+			for (Drawable component : container) {
+				if (count++ > 0) {
+					height += getGapY();
+				}
+				Dimension2D itemBounds = component.getPreferredSize();
+				w = Math.max(w, itemBounds.getWidth());
+				height += itemBounds.getHeight();
+			}
+			width += w;
+		}
+		width += insets.getRight();
+		height += insets.getBottom();
+
+		return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(width, height);
+	}
+
+	private Constraints getConstraints(Drawable component, Container container) {
+		Object constraints = container.getConstraints(component);
+		if (constraints == null || !(constraints instanceof Constraints)) {
+			constraints = defaultConstraints;
+		}
+		return (Constraints) constraints;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/graphics/layout/TableLayout.java

@@ -0,0 +1,239 @@
+package org.xbib.graphics.graph.gral.graphics.layout;
+
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Insets2D;
+
+
+/**
+ * Implementation of Layout that arranges a {@link Container}'s components
+ * according to a tabular grid with a fixed number of columns. This is similar
+ * to Java's {@link java.awt.GridLayout}, but the cells in the grid may have
+ * different dimensions.
+ */
+public class TableLayout extends AbstractLayout {
+
+	/** Number of columns. */
+	private final int cols;
+
+	/** Index of the column values in the array that is returned by
+	{@link #getInfo(Container)}. */
+	private static final int COLS = 0;
+	/** Index of the row values in the array that is returned by
+	{@link #getInfo(Container)}. */
+	private static final int ROWS = 1;
+
+	/**
+	 * Internal data class to store layout related values.
+	 */
+	private static final class Info {
+		/** Map of column/row index and maximal preferred size. */
+		public final Map<Integer, Double> sizes;
+		/** Number of columns/rows */
+		public int size;
+		/** Sum of preferred sizes in horizontal/vertical direction. */
+		public double sizeSum;
+		/** Sum of insets in horizontal/vertical direction. */
+		public double insetsSum;
+		/** Sum of gaps in horizontal/vertical direction. */
+		public double gapSum;
+		/** Mean preferred size in horizontal/vertical direction. */
+		public double sizeMean;
+		/** Space in horizontal/vertical direction which couldn't be resized
+		because the size limits of some components have been reached. */
+		public double unsizeableSpace;
+
+		/**
+		 * Initializes a new instance for storing several variables.
+		 */
+		public Info() {
+			sizes = new HashMap<>();
+		}
+	}
+
+	/**
+	 * Initializes a layout manager object with the specified number of columns
+	 * and the distances between the components.
+	 * @param cols Number of columns
+	 * @param gapH Horizontal gap.
+	 * @param gapV Vertical gap.
+	 */
+	public TableLayout(int cols, double gapH, double gapV) {
+		super(gapH, gapV);
+		if (cols <= 0) {
+			throw new IllegalArgumentException("Invalid number of columns.");
+		}
+		this.cols = cols;
+	}
+
+	/**
+	 * Initializes a layout manager object with the specified number of columns
+	 * and no gap between the components.
+	 * @param cols Number of columns.
+	 */
+	public TableLayout(int cols) {
+		this(cols, 0.0, 0.0);
+	}
+
+	/**
+	 * Calculates the preferred dimensions for all columns and rows.
+	 * @param container The container for which the dimension should be
+	 *        calculated.
+	 * @see #COLS
+	 * @see #ROWS
+	 */
+	private Info[] getInfo(Container container) {
+		Info[] infos = new Info[2];
+		infos[COLS] = new Info();
+		infos[ROWS] = new Info();
+
+		infos[COLS].size = cols;
+		infos[ROWS].size = (int) Math.ceil(container.size() / (double) cols);
+
+		// Find out the preferred dimensions for each columns and row
+		int compIndex = 0;
+		for (Drawable component : container) {
+			Integer col = compIndex%infos[COLS].size;
+			Integer row = compIndex/infos[COLS].size;
+
+			Double colWidth = infos[COLS].sizes.get(col);
+			Double rowHeight = infos[ROWS].sizes.get(row);
+
+			Dimension2D size = component.getPreferredSize();
+
+			infos[COLS].sizes.put(col, max(size.getWidth(), colWidth));
+			infos[ROWS].sizes.put(row, max(size.getHeight(), rowHeight));
+
+			compIndex++;
+		}
+
+		// Calculate container specific variables
+		Rectangle2D bounds = container.getBounds();
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+		infos[COLS].insetsSum = insets.getLeft() + insets.getRight();
+		infos[ROWS].insetsSum = insets.getTop() + insets.getBottom();
+		infos[COLS].gapSum = Math.max((infos[COLS].size - 1)*getGapX(), 0.0);
+		infos[ROWS].gapSum = Math.max((infos[ROWS].size - 1)*getGapY(), 0.0);
+		double containerWidth =
+			Math.max(bounds.getWidth() - infos[COLS].insetsSum - infos[COLS].gapSum, 0.0);
+		double containerHeight =
+			Math.max(bounds.getHeight() - infos[ROWS].insetsSum - infos[ROWS].gapSum, 0.0);
+		infos[COLS].sizeMean = (infos[COLS].size > 0) ? containerWidth/infos[COLS].size : 0.0;
+		infos[ROWS].sizeMean = (infos[ROWS].size > 0) ? containerHeight/infos[ROWS].size : 0.0;
+
+		// Values for columns and rows
+		for (Info info : infos) {
+			info.sizeSum = 0.0;
+			info.unsizeableSpace = 0.0;
+			int sizeable = 0;
+			for (double size : info.sizes.values()) {
+				info.sizeSum += size;
+				if (size >= info.sizeMean) {
+					info.unsizeableSpace += size - info.sizeMean;
+				} else {
+					sizeable++;
+				}
+			}
+			if (sizeable > 0) {
+				info.unsizeableSpace /= sizeable;
+			}
+		}
+
+		return infos;
+	}
+
+	/**
+	 * Arranges the components of the specified container according to this
+	 * layout.
+	 * @param container Container to be laid out.
+	 */
+	public void layout(Container container) {
+		Info[] infos = getInfo(container);
+
+		Rectangle2D bounds = container.getBounds();
+		Insets2D insets = container.getInsets();
+		if (insets == null) {
+			insets = new Insets2D.Double();
+		}
+		Integer lastCol = infos[COLS].size - 1;
+
+		int compIndex = 0;
+		double x = bounds.getX() + insets.getLeft();
+		double y = bounds.getY() + insets.getTop();
+		for (Drawable component : container) {
+			Integer col = compIndex%infos[COLS].size;
+			Integer row = compIndex/infos[COLS].size;
+
+			double colWidth = infos[COLS].sizes.get(col);
+			double rowHeight = infos[ROWS].sizes.get(row);
+
+			double w = Math.max(infos[COLS].sizeMean - infos[COLS].unsizeableSpace, colWidth);
+			double h = Math.max(infos[ROWS].sizeMean - infos[ROWS].unsizeableSpace, rowHeight);
+
+			if (component != null) {
+				component.setBounds(x, y, w, h);
+			}
+
+			if (col.equals(lastCol)) {
+				x = bounds.getX() + insets.getLeft();
+				y += h + getGapY();
+			} else {
+				x += w + getGapX();
+			}
+
+			compIndex++;
+		}
+	}
+
+	/**
+	 * Returns the preferred size of the specified container using this layout.
+	 * @param container Container whose preferred size is to be returned.
+	 * @return Preferred extent of the specified container.
+	 */
+	public Dimension2D getPreferredSize(Container container) {
+		Info[] infos = getInfo(container);
+
+		return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(
+			infos[COLS].sizeSum + infos[COLS].gapSum + infos[COLS].insetsSum,
+			infos[ROWS].sizeSum + infos[ROWS].gapSum + infos[ROWS].insetsSum
+		);
+	}
+
+	/**
+	 * Returns the number of desired columns.
+	 * @return Number of desired columns.
+	 */
+	public int getColumns() {
+		return cols;
+	}
+
+	/**
+	 * Returns the value that is larger. If both are equal the first value will
+	 * be returned.
+	 * @param <T> Data type for the values.
+	 * @param a First value.
+	 * @param b Second value.
+	 * @return Larger value.
+	 */
+	private static <T extends Comparable<T>> T max(T a, T b) {
+		if (a == null || b == null) {
+			if (a == null) {
+				return b;
+			} else {
+				return a;
+			}
+		}
+		if (a.compareTo(b) >= 0) {
+			return a;
+		}
+		return b;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/AbstractIOFactory.java

@@ -0,0 +1,151 @@
+package org.xbib.graphics.graph.gral.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+
+/**
+ * Abstract implementation of {@code IOFactory} which provides basic
+ * functionality.
+ *
+ * @param <T> The type of objects which should be produced by this factory
+ */
+public abstract class AbstractIOFactory<T> implements IOFactory<T> {
+
+	private final Map<String, Class<? extends T>> entries;
+
+	/**
+	 * Constructor that creates a new instance and initializes it with the name
+	 * of the corresponding properties file(s).
+	 * @param propFileName File name of the properties file(s)
+	 * @throws IOException if reading the properties file(s) failed
+	 */
+	@SuppressWarnings("unchecked")
+	protected AbstractIOFactory(String propFileName) throws IOException {
+		entries = new HashMap<>();
+
+		// Retrieve property-files
+		Enumeration<URL> propFiles;
+		propFiles = getClass().getClassLoader().getResources(propFileName);
+		if (!propFiles.hasMoreElements()) {
+			throw new IOException(MessageFormat.format(
+				"Property file not found: {0}", propFileName)); //$NON-NLS-1$
+		}
+		Properties props = new Properties();
+		while (propFiles.hasMoreElements()) {
+			URL propURL = propFiles.nextElement();
+			InputStream stream = null;
+			try {
+				stream = propURL.openStream();
+				props.load(stream);
+			} finally {
+				if (stream != null) {
+					stream.close();
+				}
+			}
+			// Parse property files and register entries as items
+			for (Map.Entry<Object, Object> prop : props.entrySet()) {
+				String mimeType = (String) prop.getKey();
+				String className = (String) prop.getValue();
+				Class<?> clazz;
+				try {
+					clazz = Class.forName(className);
+				} catch (ClassNotFoundException e) {
+					throw new IOException(e);
+				}
+				// FIXME Missing type safety check
+				entries.put(mimeType, (Class<? extends T>) clazz);
+			}
+		}
+	}
+
+	/**
+	 * Returns the capabilities for a specific format.
+	 * @param mimeType MIME type of the format
+	 * @return Capabilities for the specified format.
+	 */
+	@SuppressWarnings("unchecked")
+	public IOCapabilities getCapabilities(String mimeType) {
+		Class<? extends T> clazz = entries.get(mimeType);
+		try {
+			Method capabilitiesGetter =
+				clazz.getMethod("getCapabilities"); //$NON-NLS-1$
+			Set<IOCapabilities> capabilities =
+				(Set<IOCapabilities>) capabilitiesGetter.invoke(clazz);
+			for (IOCapabilities c : capabilities) {
+				if (c.getMimeType().equals(mimeType)) {
+					return c;
+				}
+			}
+		} catch (SecurityException | InvocationTargetException | IllegalAccessException | IllegalArgumentException | NoSuchMethodException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+		return null;
+	}
+
+	/**
+	 * Returns a list of capabilities for all supported formats.
+	 * @return Supported capabilities.
+	 */
+	public List<IOCapabilities> getCapabilities() {
+		List<IOCapabilities> caps =
+				new ArrayList<>(entries.size());
+		for (String mimeType : entries.keySet()) {
+			IOCapabilities capability = getCapabilities(mimeType);
+			if (capability != null) {
+				caps.add(capability);
+			}
+		}
+		return caps;
+	}
+
+	/**
+	 * Returns an array of Strings containing all supported formats.
+	 * @return Supported formats.
+	 */
+	public String[] getSupportedFormats() {
+		String[] formats = new String[entries.size()];
+		entries.keySet().toArray(formats);
+		return formats;
+	}
+
+	/**
+	 * Returns whether the specified MIME type is supported.
+	 * @param mimeType MIME type.
+	 * @return {@code true} if supported, otherwise {@code false}.
+	 */
+	public boolean isFormatSupported(String mimeType) {
+		return entries.containsKey(mimeType);
+	}
+
+	/**
+	 * Returns the type of factory products for a specified format.
+	 * @param type Format.
+	 * @return Class type to create new instances.
+	 */
+	protected Class<? extends T> getTypeClass(String type) {
+		return entries.get(type);
+	}
+
+	/**
+	 * Returns an object for reading or writing the specified format.
+	 * @param mimeType MIME type.
+	 * @return Reader or writer for the specified MIME type.
+	 */
+	public T get(String mimeType) {
+		// TODO Auto-generated method stub
+		return null;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/IOCapabilities.java

@@ -0,0 +1,66 @@
+package org.xbib.graphics.graph.gral.io;
+
+/**
+ * Class that stores information on a <i>reader</i> or <i>writer</i>
+ * implementation.
+ */
+public class IOCapabilities {
+	/** Short format name. */
+	private final String format;
+	/** Long format name. */
+	private final String name;
+	/** MIME type of format. */
+	private final String mimeType;
+	/** File extensions commonly used for this format. */
+	private final String[] extensions;
+
+	/**
+	 * Creates a new {@code IOCapabilities} object with the specified
+	 * format, name, MIME-Type and filename extensions.
+	 * @param format Format.
+	 * @param name Name.
+	 * @param mimeType MIME-Type
+	 * @param extensions Extensions.
+	 */
+	public IOCapabilities(String format, String name, String mimeType,
+			String[] extensions) {
+		this.format = format;
+		this.name = name;
+		this.mimeType = mimeType;
+		// TODO Check that there is at least one filename extension
+		this.extensions = extensions;
+	}
+
+	/**
+	 * Returns the format.
+	 * @return Format.
+	 */
+	public String getFormat() {
+		return format;
+	}
+
+	/**
+	 * Returns the name of the format.
+	 * @return Name.
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Returns the MIME-Type of the format.
+	 * @return Format.
+	 */
+	public String getMimeType() {
+		return mimeType;
+	}
+
+	/**
+	 * Returns an array with Strings containing all possible filename
+	 * extensions.
+	 * @return Filename Extensions.
+	 */
+	public String[] getExtensions() {
+		return extensions;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/IOCapabilitiesStorage.java

@@ -0,0 +1,37 @@
+package org.xbib.graphics.graph.gral.io;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Abstract class that provides the basic functions to store capabilities of
+ * a reader or a writer implementation.
+ */
+public abstract class IOCapabilitiesStorage {
+	/** Set of all registered capabilities. */
+	private static final Set<IOCapabilities> capabilities
+		= new HashSet<>();
+
+	/**
+	 * Initializes a new storage instance.
+	 */
+	protected IOCapabilitiesStorage() {
+	}
+
+	/**
+	 * Returns a {@code Set} with capabilities for all supported formats.
+	 * @return Capabilities.
+	 */
+	public static Set<IOCapabilities> getCapabilities() {
+		return Collections.unmodifiableSet(capabilities);
+	}
+
+	/**
+	 * Adds the specified capabilities to the Set of supported formats.
+	 * @param capabilities Capabilities to be added.
+	 */
+	protected static void addCapabilities(IOCapabilities capabilities) {
+		IOCapabilitiesStorage.capabilities.add(capabilities);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/IOFactory.java

@@ -0,0 +1,44 @@
+package org.xbib.graphics.graph.gral.io;
+
+import java.util.List;
+
+/**
+ * Interface for factories producing input (reader) or output (writer) classes.
+ * This is be used to create a extensible plug-in system for reading or writing
+ * data.
+ * @param <T> Class of the objects produced by the factory.
+ */
+public interface IOFactory<T> {
+	/**
+	 * Returns an object for reading or writing the specified format.
+	 * @param mimeType MIME type.
+	 * @return Reader or writer for the specified MIME type.
+	 */
+	T get(String mimeType);
+
+	/**
+	 * Returns the capabilities for a specific format.
+	 * @param mimeType MIME type of the format
+	 * @return Capabilities for the specified format.
+	 */
+	IOCapabilities getCapabilities(String mimeType);
+
+	/**
+	 * Returns a list of capabilities for all supported formats.
+	 * @return Supported capabilities.
+	 */
+	List<IOCapabilities> getCapabilities();
+
+	/**
+	 * Returns an array of Strings containing all supported formats.
+	 * @return Supported formats.
+	 */
+	String[] getSupportedFormats();
+
+	/**
+	 * Returns whether the specified MIME type is supported.
+	 * @param mimeType MIME type.
+	 * @return {@code true} if supported, otherwise {@code false}.
+	 */
+	boolean isFormatSupported(String mimeType);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/AbstractDataReader.java

@@ -0,0 +1,72 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.io.IOCapabilitiesStorage;
+
+/**
+ * Base implementation for classes that read data sources from input streams.
+ */
+public abstract class AbstractDataReader extends IOCapabilitiesStorage
+		implements DataReader {
+	/** Settings stored as (key, value) pairs. */
+	private final Map<String, Object> settings;
+	/** Default settings. */
+	private final Map<String, Object> defaults;
+	/** Data format as MIME type string. */
+	private final String mimeType;
+
+	/**
+	 * Initializes a new reader with MIME type information.
+	 * @param mimeType MIME type
+	 */
+	public AbstractDataReader(String mimeType) {
+		settings = new HashMap<>();
+		defaults = new HashMap<>();
+		this.mimeType = mimeType;
+	}
+
+	/**
+	 * Returns the MIME type.
+	 * @return MIME type string.
+	 */
+	public String getMimeType() {
+		return mimeType;
+	}
+
+	/**
+	 * Returns the setting for the specified key.
+	 * @param <T> return type
+	 * @param key key of the setting
+	 * @return the value of the setting
+	 */
+	@SuppressWarnings("unchecked")
+	public <T> T getSetting(String key) {
+		if (!settings.containsKey(key)) {
+			return (T) defaults.get(key);
+		}
+		return (T) settings.get(key);
+	}
+
+	/**
+	 * Sets the setting for the specified key.
+	 * @param <T> value type
+	 * @param key key of the setting
+	 * @param value value of the setting
+	 */
+	public <T> void setSetting(String key, T value) {
+		settings.put(key, value);
+	}
+
+	/**
+	 * Defines a default value for the setting with the specified key.
+	 * @param <T> Data type of value.
+	 * @param key Setting key.
+	 * @param value Default value.
+	 */
+	protected <T> void setDefault(String key, T value) {
+		defaults.put(key, value);
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/AbstractDataWriter.java

@@ -0,0 +1,72 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.io.IOCapabilitiesStorage;
+
+/**
+ * Base implementation for classes that write data sources to output streams.
+ */
+public abstract class AbstractDataWriter extends IOCapabilitiesStorage
+		implements DataWriter {
+	/** Settings stored as (key, value) pairs. */
+	private final Map<String, Object> settings;
+	/** Default settings. */
+	private final Map<String, Object> defaults;
+	/** Data format as MIME type string. */
+	private final String mimeType;
+
+	/**
+	 * Initializes a new writer with MIME type information.
+	 * @param mimeType MIME type
+	 */
+	public AbstractDataWriter(String mimeType) {
+		settings = new HashMap<>();
+		defaults = new HashMap<>();
+		this.mimeType = mimeType;
+	}
+
+	/**
+	 * Returns the MIME type.
+	 * @return MIME type string.
+	 */
+	public String getMimeType() {
+		return mimeType;
+	}
+
+	/**
+	 * Returns the setting for the specified key.
+	 * @param <T> return type
+	 * @param key key of the setting
+	 * @return the value of the setting
+	 */
+	@SuppressWarnings("unchecked")
+	public <T> T getSetting(String key) {
+		if (!settings.containsKey(key)) {
+			return (T) defaults.get(key);
+		}
+		return (T) settings.get(key);
+	}
+
+	/**
+	 * Sets the setting for the specified key.
+	 * @param <T> value type
+	 * @param key key of the setting
+	 * @param value value of the setting
+	 */
+	public <T> void setSetting(String key, T value) {
+		settings.put(key, value);
+	}
+
+	/**
+	 * Defines a default value for the setting with the specified key.
+	 * @param <T> Data type of value
+	 * @param key Setting key
+	 * @param value Default value
+	 */
+	protected <T> void setDefault(String key, T value) {
+		defaults.put(key, value);
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/CSVReader.java

@@ -0,0 +1,269 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.text.MessageFormat;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Scanner;
+import java.util.regex.Pattern;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.DataTable;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.util.Messages;
+import org.xbib.graphics.graph.gral.util.StatefulTokenizer;
+import org.xbib.graphics.graph.gral.util.StatefulTokenizer.Token;
+
+/**
+ * <p>Class that creates a {@code DataSource} from file contents which are
+ * separated by a certain delimiter character. The delimiter is chosen based on
+ * the file type but can also be set manually. By default the comma character
+ * will be used as a delimiter for separating columns.</p>
+ * <p>{@code CSVReader} instances should be obtained by the
+ * {@link DataReaderFactory} rather than being created manually:</p>
+ * <pre>
+ * DataReaderFactory factory = DataReaderFactory.getInstance();
+ * DataReader reader = factory.get("text/csv");
+ * reader.read(new FileInputStream(filename), Integer.class, Double.class);
+ * </pre>
+ * @see <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>
+ */
+public class CSVReader extends AbstractDataReader {
+	/** Key for specifying a {@link Character} value that defines the
+	delimiting character used to separate columns. */
+	public static final String SEPARATOR_CHAR = "separator"; //$NON-NLS-1$
+
+	static {
+		addCapabilities(new IOCapabilities(
+			"CSV", //$NON-NLS-1$
+			Messages.getString("DataIO.csvDescription"), //$NON-NLS-1$
+			"text/csv", //$NON-NLS-1$
+			new String[] {"csv", "txt"} //$NON-NLS-1$ //$NON-NLS-2$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"TSV", //$NON-NLS-1$
+			Messages.getString("DataIO.tsvDescription"), //$NON-NLS-1$
+			"text/tab-separated-values", //$NON-NLS-1$
+			new String[] {
+				"tsv", "tab", "txt"} //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+		));
+	}
+
+	/**
+	 * Token types for analyzing CSV or TSV input.
+	 */
+	private enum CSVTokenType {
+		/** Type for text tokens containing empty content. */
+		EMPTY_SPACE,
+		/** Type for text tokens containing value content. */
+		TEXT,
+		/** Type for quotes that may wrap value content. */
+		QUOTE,
+		/** Type for row separators. */
+		ROW_SEPARATOR,
+		/** Type for column separators. */
+		COLUMN_SEPARATOR,
+	}
+
+	/**
+	 *
+	 */
+	private static final class CSVTokenizer extends StatefulTokenizer {
+		/**
+		 * Initializes a new tokenizer instance with a grammar to analyze CSV
+		 * or TSV content. The character that separates columns must be
+		 * provided.
+		 * @param separator Column separator character.
+		 */
+		public CSVTokenizer(char separator) {
+			addJoinedType(CSVTokenType.TEXT);
+			addIgnoredType(CSVTokenType.QUOTE);
+
+			// Basic Set of rules for analyzing CSV content
+			putRules(
+				new Rule("\n|\r\n|\r", CSVTokenType.ROW_SEPARATOR),
+				new Rule(Pattern.quote(String.valueOf(separator)),
+						CSVTokenType.COLUMN_SEPARATOR),
+				new Rule("\"", CSVTokenType.QUOTE, "quoted"),
+				new Rule("[ \t]+", CSVTokenType.EMPTY_SPACE),
+				new Rule(".", CSVTokenType.TEXT)
+			);
+			// Set of rules that is valid inside quoted content
+			putRules("quoted",
+				new Rule("(\")\"", CSVTokenType.TEXT),
+				new Rule("\"", CSVTokenType.QUOTE, "#pop"),
+				new Rule(".", CSVTokenType.TEXT)
+			);
+		}
+	}
+
+	/**
+	 * Creates a new instance with the specified MIME type. The delimiter is
+	 * set depending on the MIME type parameter. By default a comma is used as
+	 * a delimiter.
+	 * @param mimeType MIME type of the file format to be read.
+	 */
+	public CSVReader(String mimeType) {
+		super(mimeType);
+		if ("text/tab-separated-values".equals(mimeType)) { //$NON-NLS-1$
+			setDefault(SEPARATOR_CHAR, '\t');
+		} else {
+			setDefault(SEPARATOR_CHAR, ',');
+		}
+	}
+
+	/**
+	 * Returns a DataSource that was imported.
+	 * @param input Input to be read.
+	 * @param types Number types for the columns of the DataSource.
+	 * @return DataSource Imported data.
+	 * @throws IOException when the file format is not valid or when
+	 *         experiencing an error during file operations.
+	 */
+	@SuppressWarnings("unchecked")
+	public DataSource read(InputStream input, Class<? extends Comparable<?>>... types)
+			throws IOException {
+		// Read all contents from the input stream
+		Scanner scanner = new Scanner(input).useDelimiter("\\Z");
+		String content = scanner.next();
+
+		// Tokenize the string
+		Character separator = getSetting(SEPARATOR_CHAR);
+		CSVTokenizer tokenizer = new CSVTokenizer(separator);
+		List<Token> tokens = tokenizer.tokenize(content);
+
+		// Add row token if there was no trailing line break
+		Token lastToken = tokens.get(tokens.size() - 1);
+		if (lastToken.getType() != CSVTokenType.ROW_SEPARATOR) {
+			Token eof = new Token(lastToken.getEnd(), lastToken.getEnd(),
+				CSVTokenType.ROW_SEPARATOR, "");
+			tokens.add(eof);
+		}
+
+		// Find methods for all column data types that can be used to convert
+		// the text to the column data type
+		Map<Class<? extends Comparable<?>>, Method> parseMethods =
+				new HashMap<>();
+		for (Class<? extends Comparable<?>> type : types) {
+			if (parseMethods.containsKey(type)) {
+				continue;
+			}
+			Method parseMethod = getParseMethod(type);
+			if (parseMethod != null) {
+				parseMethods.put(type, parseMethod);
+			}
+		}
+
+		// Process the data and store the data.
+		DataTable data = new DataTable(types);
+		List<Comparable<?>> row = new LinkedList<>();
+		int rowIndex = 0;
+		int colIndex = 0;
+		StringBuilder cellContent = new StringBuilder();
+		for (Token token : tokens) {
+			if (token.getType() == CSVTokenType.TEXT ||
+					token.getType() == CSVTokenType.EMPTY_SPACE) {
+				// Store the token text
+				cellContent.append(token.getContent());
+			} else if (token.getType() == CSVTokenType.COLUMN_SEPARATOR ||
+					token.getType() == CSVTokenType.ROW_SEPARATOR) {
+				// Check for a valid number of columns
+				if (colIndex >= types.length) {
+					throw new IllegalArgumentException(MessageFormat.format(
+						"Too many columns in line {0,number,integer}: got {1,number,integer}, but expected {2,number,integer}.", //$NON-NLS-1$
+						rowIndex + 1, colIndex + 1, types.length));
+				}
+
+				// We need to add the cell to the row in both cases because
+				// rows don't have a trailing column token
+				Class<? extends Comparable<?>> colType = types[colIndex];
+				Method parseMethod = parseMethods.get(colType);
+				Comparable<?> cell = null;
+				try {
+					cell = (Comparable<?>) parseMethod.invoke(
+						null, cellContent.toString().trim());
+
+				} catch (IllegalArgumentException e) {
+					throw new RuntimeException(MessageFormat.format(
+						"Could not invoke method for parsing data type {0} in column {1,number,integer}.", //$NON-NLS-1$
+						types[colIndex].getSimpleName(), colIndex));
+				} catch (IllegalAccessException e) {
+					throw new RuntimeException(MessageFormat.format(
+						"Could not access method for parsing data type {0} in column {1,number,integer}.", //$NON-NLS-1$
+						types[colIndex].getSimpleName(), colIndex));
+				} catch (InvocationTargetException e) {
+					if (cellContent.length() > 0) {
+						throw new IOException(MessageFormat.format(
+							"Type mismatch in line {0,number,integer}, column {1,number,integer}: got \"{2}\", but expected {3} value.", //$NON-NLS-1$
+							rowIndex + 1, colIndex + 1, cellContent.toString(), colType.getSimpleName()));
+					}
+				}
+				row.add(cell);
+				colIndex++;
+
+				if (token.getType() == CSVTokenType.ROW_SEPARATOR) {
+					// Check for a valid number of columns
+					if (row.size() < types.length) {
+						throw new IllegalArgumentException(MessageFormat.format(
+							"Not enough columns in line {0,number,integer}: got {1,number,integer}, but expected {2,number,integer}.", //$NON-NLS-1$
+							rowIndex + 1, row.size(), types.length));
+					}
+
+					// Add the row to the table
+					data.add(row);
+					rowIndex++;
+
+					// Start a new row
+					row.clear();
+					colIndex = 0;
+				}
+				cellContent = new StringBuilder();
+			}
+		}
+
+		return data;
+	}
+
+	/**
+	 * Returns a method that can return a parsed value of the specified type.
+	 * @param c Desired type.
+	 * @return Method that parses a data type.
+	 */
+	private static Method getParseMethod(Class<?> c) {
+		Method parse = null;
+
+		if (String.class.isAssignableFrom(c)) {
+			try {
+				parse = String.class.getMethod("valueOf", Object.class);
+			} catch (NoSuchMethodException e) {
+			}
+		} else {
+			for (Method m : c.getMethods()) {
+				boolean isStatic = m.toString().contains("static"); //$NON-NLS-1$
+				if (!isStatic) {
+					continue;
+				}
+				Class<?>[] types = m.getParameterTypes();
+				boolean hasStringParameter =
+					(types.length == 1) && String.class.equals(types[0]);
+				if (!hasStringParameter) {
+					continue;
+				}
+				// Check method name for a pattern like "parseInt*" for Integer or
+				// "parseSho*" for Short to avoid collisions
+				if (!m.getName().startsWith("parse" + c.getSimpleName().substring(0, 3))) {  //$NON-NLS-1$
+					continue;
+				}
+				parse = m;
+			}
+		}
+
+		return parse;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/CSVWriter.java

@@ -0,0 +1,91 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.util.Messages;
+
+/**
+ * <p>Class that writes all values of a {@code DataSource} to a character
+ * separated file. The file then stores the values separated by a certain
+ * delimiter character. The delimiter is chosen based on the file type but can
+ * also be set manually. By default the comma character will be used as a
+ * delimiter for separating columns. Lines end with a carriage return and a
+ * line feed character.</p>
+ * <p>{@code CSVWriter} instances should be obtained by the
+ * {@link DataWriterFactory} rather than being created manually:</p>
+ * <pre>
+ * DataWriterFactory factory = DataWriterFactory.getInstance();
+ * DataWriter writer = factory.get("text/csv");
+ * writer.write(data, new FileOutputStream(filename));
+ * </pre>
+ * @see <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>
+ */
+public class CSVWriter extends AbstractDataWriter {
+	/** Key for specifying a {@link Character} value that defines the
+	delimiting character used to separate columns. */
+	public static final String SEPARATOR_CHAR = CSVReader.SEPARATOR_CHAR;
+
+	static {
+		addCapabilities(new IOCapabilities(
+			"CSV", //$NON-NLS-1$
+			Messages.getString("DataIO.csvDescription"), //$NON-NLS-1$
+			"text/csv", //$NON-NLS-1$
+			new String[] {"csv", "txt"} //$NON-NLS-1$ //$NON-NLS-2$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"TSV", //$NON-NLS-1$
+			Messages.getString("DataIO.tsvDescription"), //$NON-NLS-1$
+			"text/tab-separated-values", //$NON-NLS-1$
+			new String[] {
+				"tsv", "tab", "txt"} //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+		));
+	}
+
+	/**
+	 * Creates a new instance with the specified MIME-Type. The delimiter is
+	 * set depending on the MIME type parameter. By default a comma is used as
+	 * a delimiter.
+	 * @param mimeType MIME-Type of the output file.
+	 */
+	public CSVWriter(String mimeType) {
+		super(mimeType);
+		if ("text/tab-separated-values".equals(mimeType)) { //$NON-NLS-1$
+			setDefault(SEPARATOR_CHAR, '\t'); //$NON-NLS-1$
+		} else {
+			setDefault(SEPARATOR_CHAR, ','); //$NON-NLS-1$
+		}
+	}
+
+	/**
+	 * Stores the specified data source.
+	 * @param data DataSource to be stored.
+	 * @param output OutputStream to be written to.
+	 * @throws IOException if writing the data failed
+	 */
+	public void write(DataSource data, OutputStream output) throws IOException {
+		Character separator = getSetting(SEPARATOR_CHAR);
+		OutputStreamWriter writer = new OutputStreamWriter(output);
+
+		int i = 0;
+		int colCount = data.getColumnCount();
+		for (Comparable<?> cell : data) {
+			writer.write(String.valueOf(cell));
+
+			int col = i % colCount;
+			if (col < colCount - 1) {
+				writer.write(separator);
+			} else {
+				writer.write("\r\n"); //$NON-NLS-1$
+			}
+			i++;
+		}
+
+		writer.close();
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/DataReader.java

@@ -0,0 +1,40 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+
+/**
+ * Interface that provides a function to retrieve a data source.
+ */
+public interface DataReader {
+	/**
+	 * Returns a data source that contains the imported data.
+	 * @param input Input to be read.
+	 * @param types Types for the columns of the data source.
+	 * @return Imported data.
+	 * @throws IOException when the file format is not valid or when
+	 *         experiencing an error during file operations.
+	 */
+	@SuppressWarnings("unchecked")
+	DataSource read(InputStream input, Class<? extends Comparable<?>>... types)
+		throws IOException;
+
+	/**
+	 * Returns the setting for the specified key.
+	 * @param <T> return type
+	 * @param key key of the setting
+	 * @return the value of the setting
+	 */
+	<T> T getSetting(String key);
+
+	/**
+	 * Sets the setting for the specified key.
+	 * @param <T> value type
+	 * @param key key of the setting
+	 * @param value value of the setting
+	 */
+	<T> void setSetting(String key, T value);
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/DataReaderFactory.java

@@ -0,0 +1,71 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.text.MessageFormat;
+
+import org.xbib.graphics.graph.gral.io.AbstractIOFactory;
+
+/**
+ * <p>A factory class that produces {@code DataReader} instances for a
+ * specified format. The produced readers can be used to retrieve data from
+ * an {@code InputStream} and to get a {@code DataSource} instance.</p>
+ * <p>Example usage:</p>
+ * <pre>
+ * DataReaderFactory factory = DataReaderFactory.getInstance();
+ * DataReader reader = factory.get("text/csv");
+ * DataSource = reader.read(new FileInputStream(filename), Double.class);
+ * </pre>
+ */
+public final class DataReaderFactory extends AbstractIOFactory<DataReader> {
+	/** Singleton instance. */
+	private static DataReaderFactory instance;
+
+	/**
+	 * Constructor that initializes the factory.
+	 * @throws IOException if the properties file could not be found.
+	 */
+	private DataReaderFactory() throws IOException {
+		super("datareaders.properties"); //$NON-NLS-1$
+	}
+
+	/**
+	 * Returns the instance of the factory.
+	 * @return Instance of the factory.
+	 */
+	public static DataReaderFactory getInstance() {
+		if (instance == null) {
+			try {
+				instance = new DataReaderFactory();
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+		return instance;
+	}
+
+	@Override
+	public DataReader get(String mimeType) {
+		DataReader reader = null;
+		Class<? extends DataReader> clazz = getTypeClass(mimeType);
+		//IOCapabilities capabilities = getCapabilities(mimeType);
+		try {
+			if (clazz != null) {
+				Constructor<? extends DataReader> constructor =
+					clazz.getDeclaredConstructor(String.class);
+				reader = constructor.newInstance(mimeType);
+			}
+		} catch (SecurityException | InvocationTargetException | IllegalAccessException | InstantiationException | IllegalArgumentException | NoSuchMethodException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+		if (reader == null) {
+			throw new IllegalArgumentException(MessageFormat.format(
+					"Unsupported MIME type: {0}", mimeType)); //$NON-NLS-1$
+		}
+
+		return reader;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/DataWriter.java

@@ -0,0 +1,36 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+
+/**
+ * Interface that provides a function to store a data source.
+ */
+public interface DataWriter {
+	/**
+	 * Stores the specified data source.
+	 * @param data DataSource to be stored.
+	 * @param output OutputStream to be written to.
+	 * @throws IOException if writing the data failed
+	 */
+	void write(DataSource data, OutputStream output) throws IOException;
+
+	/**
+	 * Returns the setting for the specified key.
+	 * @param <T> return type
+	 * @param key key of the setting
+	 * @return the value of the setting
+	 */
+	<T> T getSetting(String key);
+
+	/**
+	 * Sets the setting for the specified key.
+	 * @param <T> value type
+	 * @param key key of the setting
+	 * @param value value of the setting
+	 */
+	<T> void setSetting(String key, T value);
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/DataWriterFactory.java

@@ -0,0 +1,71 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.text.MessageFormat;
+
+import org.xbib.graphics.graph.gral.io.AbstractIOFactory;
+
+/**
+ * <p>A factory class that produces {@code DataWriter} instances for a
+ * specified format. The produced writers can be used to output a
+ * {@code DataSource} to a data sink.</p>
+ * <p>Example usage:</p>
+ * <pre>
+ * DataWriterFactory factory = DataWriterFactory.getInstance();
+ * DataWriter writer = factory.get("image/png");
+ * writer.write(data);
+ * </pre>
+ */
+public final class DataWriterFactory extends AbstractIOFactory<DataWriter> {
+	/** Singleton instance. */
+	private static DataWriterFactory instance;
+
+	/**
+	 * Constructor that initializes the factory.
+	 * @throws IOException if the properties file could not be found.
+	 */
+	private DataWriterFactory() throws IOException {
+		super("datawriters.properties");
+	}
+
+	/**
+	 * Returns the instance of the factory.
+	 * @return Instance of the factory.
+	 */
+	public static DataWriterFactory getInstance() {
+		if (instance == null) {
+			try {
+				instance = new DataWriterFactory();
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+		return instance;
+	}
+
+	@Override
+	public DataWriter get(String mimeType) {
+		DataWriter writer = null;
+		Class<? extends DataWriter> clazz = getTypeClass(mimeType);
+		//IOCapabilities capabilities = getCapabilities(mimeType);
+		try {
+			if (clazz != null) {
+				Constructor<? extends DataWriter> constructor =
+					clazz.getDeclaredConstructor(String.class);
+				writer = constructor.newInstance(mimeType);
+			}
+		} catch (SecurityException | InvocationTargetException | IllegalAccessException | InstantiationException | IllegalArgumentException | NoSuchMethodException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+		if (writer == null) {
+			throw new IllegalArgumentException(MessageFormat.format(
+					"Unsupported MIME type: {0}", mimeType)); //$NON-NLS-1$
+		}
+
+		return writer;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/ImageReader.java

@@ -0,0 +1,109 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+
+import javax.imageio.ImageIO;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.DataTable;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.util.Messages;
+
+/**
+ * Class that reads a data source from a binary image file. This class
+ * shouldn't be used directly but using the {@link DataReaderFactory}.
+ */
+public class ImageReader extends AbstractDataReader {
+	static {
+		addCapabilities(new IOCapabilities(
+			"BMP",
+			Messages.getString("ImageIO.bmpDescription"),
+			"image/bmp",
+			new String[] {"bmp", "dib"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"GIF",
+			Messages.getString("ImageIO.gifDescription"),
+			"image/gif",
+			new String[] {"gif"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"JPEG/JFIF",
+			Messages.getString("ImageIO.jpegDescription"),
+			"image/jpeg",
+			new String[] {
+				"jpg", "jpeg", "jpe",
+				"jif", "jfif", "jfi"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"PNG",
+			Messages.getString("ImageIO.pngDescription"),
+			"image/png",
+			new String[] {"png"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"WBMP",
+			Messages.getString("ImageIO.wbmpDescription"),
+			"image/vnd.wap.wbmp",
+			new String[] {"wbmp"}
+		));
+	}
+
+	/**
+	 * Creates a new instance with the specified MIME type.
+	 * @param mimeType MIME type of the file format to be read.
+	 */
+	public ImageReader(String mimeType) {
+		super(mimeType);
+		setDefault("factor", 1.0);
+		setDefault("offset", 0.0);
+	}
+
+	/**
+	 * Returns a data source that was imported.
+	 * @param input Input to be read.
+	 * @param types Number types for the columns of the data source.
+	 * @return DataSource Imported data.
+	 * @throws IOException when the file format is not valid or when
+	 *         experiencing an error during file operations.
+	 */
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	public DataSource read(InputStream input, Class<? extends Comparable<?>>... types)
+			throws IOException {
+		BufferedImage image = ImageIO.read(input);
+
+		int w = image.getWidth();
+		int h = image.getHeight();
+
+		Class[] colTypes = new Class[w];
+		Arrays.fill(colTypes, Double.class);
+		DataTable data = new DataTable(colTypes);
+
+		double factor = this.<Number>getSetting("factor").doubleValue();
+		double offset = this.<Number>getSetting("offset").doubleValue();
+
+		int[] pixelData = new int[w];
+		Double[] rowData = new Double[w];
+		for (int y = 0; y < h; y++) {
+			image.getRGB(0, y, pixelData.length, 1, pixelData, 0, 0);
+			for (int x = 0; x < pixelData.length; x++) {
+				//double a = (pixelData[x] >> 24) & 0xFF;
+				double r = (pixelData[x] >> 16) & 0xFF;
+				//double g = (pixelData[x] >>  8) & 0xFF;
+				//double b = (pixelData[x] >>  0) & 0xFF;
+				rowData[x] = r*factor + offset;
+			}
+			data.add(rowData);
+		}
+
+		return data;
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/data/ImageWriter.java

@@ -0,0 +1,115 @@
+package org.xbib.graphics.graph.gral.io.data;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.text.MessageFormat;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import javax.imageio.ImageIO;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.Messages;
+
+/**
+ * Class that writes a data source to a binary image file. This class
+ * shouldn't be used directly but using the {@link DataWriterFactory}.
+ */
+public class ImageWriter extends AbstractDataWriter {
+	static {
+		addCapabilities(new IOCapabilities(
+			"BMP",
+			Messages.getString("ImageIO.bmpDescription"),
+			"image/bmp",
+			new String[] {"bmp", "dib"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"GIF",
+			Messages.getString("ImageIO.gifDescription"),
+			"image/gif",
+			new String[] {"gif"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"JPEG/JFIF",
+			Messages.getString("ImageIO.jpegDescription"),
+			"image/jpeg",
+			new String[] {
+				"jpg", "jpeg", "jpe",
+				"jif", "jfif", "jfi"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"PNG",
+			Messages.getString("ImageIO.pngDescription"),
+			"image/png",
+			new String[] {"png"}
+		));
+
+		addCapabilities(new IOCapabilities(
+			"WBMP",
+			Messages.getString("ImageIO.wbmpDescription"),
+			"image/vnd.wap.wbmp",
+			new String[] {"wbmp"}
+		));
+	}
+
+	/**
+	 * Creates a new instance with the specified MIME type.
+	 * @param mimeType MIME type of the file format to be read.
+	 */
+	public ImageWriter(String mimeType) {
+		super(mimeType);
+		setDefault("factor", 1.0); //$NON-NLS-1$
+		setDefault("offset", 0.0); //$NON-NLS-1$
+	}
+
+	/**
+	 * Stores the specified data source.
+	 * @param data DataSource to be stored.
+	 * @param output OutputStream to be written to.
+	 * @throws IOException if writing the data failed
+	 */
+	public void write(DataSource data, OutputStream output) throws IOException {
+		int w = data.getColumnCount();
+		int h = data.getRowCount();
+
+		double factor = this.<Number>getSetting("factor").doubleValue(); //$NON-NLS-1$
+		double offset = this.<Number>getSetting("offset").doubleValue(); //$NON-NLS-1$
+
+		byte[] pixelData = new byte[w*h];
+		int pos = 0;
+		for (int y = 0; y < h; y++) {
+			for (int x = 0; x < w; x++) {
+				Comparable<?> cell = data.get(x, y);
+				if (!(cell instanceof Number)) {
+					continue;
+				}
+				Number numericCell = (Number) cell;
+				double value = numericCell.doubleValue()*factor + offset;
+				byte v = (byte) Math.round(MathUtils.limit(value, 0.0, 255.0));
+				pixelData[pos++] = v;
+			}
+		}
+
+        BufferedImage image =
+        	new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
+        image.getRaster().setDataElements(0, 0, w, h, pixelData);
+
+        Iterator<javax.imageio.ImageWriter> writers =
+        	ImageIO.getImageWritersByMIMEType(getMimeType());
+        try {
+        	javax.imageio.ImageWriter writer = writers.next();
+        	writer.setOutput(ImageIO.createImageOutputStream(output));
+        	writer.write(image);
+        } catch (NoSuchElementException e) {
+        	throw new IOException(MessageFormat.format(
+        			"No writer found for MIME type {0}.", getMimeType())); //$NON-NLS-1$
+        }
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/plots/BitmapWriter.java

@@ -0,0 +1,177 @@
+package org.xbib.graphics.graph.gral.io.plots;
+
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.Iterator;
+
+import javax.imageio.ImageIO;
+import javax.imageio.ImageWriter;
+import javax.imageio.stream.ImageOutputStream;
+
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.io.IOCapabilitiesStorage;
+import org.xbib.graphics.graph.gral.util.Messages;
+
+
+/**
+ * Class that stores {@code Drawable} instances as bitmap graphics.
+ * Supported formats:
+ * <ul>
+ *   <li>Windows Bitmap (BMP)</li>
+ *   <li>Graphics Interchange Format (GIF)</li>
+ *   <li>JPEG File Interchange Format (JPEG)</li>
+ *   <li>Portable Network Graphics (PNG)</li>
+ *   <li>Wireless Application Protocol Bitmap (WBMP)</li>
+ * </ul>
+ * <p>This class shouldn't be used directly but using the
+ * {@link DrawableWriterFactory}.</p>
+ */
+public class BitmapWriter extends IOCapabilitiesStorage
+		implements DrawableWriter {
+	static {
+		addCapabilities(new IOCapabilities(
+			"BMP", //$NON-NLS-1$
+			Messages.getString("ImageIO.bmpDescription"), //$NON-NLS-1$
+			"image/bmp", //$NON-NLS-1$
+			new String[] {"bmp", "dib"} //$NON-NLS-1$ //$NON-NLS-2$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"GIF", //$NON-NLS-1$
+			Messages.getString("ImageIO.gifDescription"), //$NON-NLS-1$
+			"image/gif", //$NON-NLS-1$
+			new String[] {"gif"} //$NON-NLS-1$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"JPEG/JFIF", //$NON-NLS-1$
+			Messages.getString("ImageIO.jpegDescription"), //$NON-NLS-1$
+			"image/jpeg", //$NON-NLS-1$
+			new String[] {
+				"jpg", "jpeg", "jpe", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+				"jif", "jfif", "jfi"} //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"PNG", //$NON-NLS-1$
+			Messages.getString("ImageIO.pngDescription"), //$NON-NLS-1$
+			"image/png", //$NON-NLS-1$
+			new String[] {"png"} //$NON-NLS-1$
+		));
+
+		addCapabilities(new IOCapabilities(
+			"WBMP", //$NON-NLS-1$
+			Messages.getString("ImageIO.wbmpDescription"), //$NON-NLS-1$
+			"image/vnd.wap.wbmp", //$NON-NLS-1$
+			new String[] {"wbmp"} //$NON-NLS-1$
+		));
+	}
+
+	/** Data format as MIME type string. */
+	private final String mimeType;
+	/** Bitmap raster format. */
+	private final int rasterFormat;
+
+	/**
+	 * Creates a new {@code BitmapWriter} object with the specified
+	 * MIME-Type.
+	 * @param mimeType Output MIME-Type.
+	 */
+	protected BitmapWriter(String mimeType) {
+		this.mimeType = mimeType;
+
+		boolean isAlphaSupported =
+			"image/png".equals(mimeType); //$NON-NLS-1$
+		boolean isColorSupported =
+			!"image/vnd.wap.wbmp".equals(mimeType); //$NON-NLS-1$
+		boolean isGrayscaleSupported =
+			!"image/vnd.wap.wbmp".equals(mimeType); //$NON-NLS-1$
+
+		if (isColorSupported) {
+			if (isAlphaSupported) {
+				rasterFormat = BufferedImage.TYPE_INT_ARGB;
+			} else {
+				rasterFormat = BufferedImage.TYPE_INT_RGB;
+			}
+		} else {
+			if (isGrayscaleSupported) {
+				rasterFormat = BufferedImage.TYPE_BYTE_GRAY;
+			} else {
+				rasterFormat = BufferedImage.TYPE_BYTE_BINARY;
+			}
+		}
+
+		// TODO Option to set transparency
+		// TODO Possibility to choose a background color
+	}
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	public void write(Drawable d, OutputStream destination,
+			double width, double height) throws IOException {
+		write(d, destination, 0.0, 0.0, width, height);
+	}
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param x Horizontal position.
+	 * @param y Vertical position.
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	public void write(Drawable d, OutputStream destination,
+			double x, double y, double width, double height)
+			throws IOException {
+		BufferedImage image = new BufferedImage(
+				(int)Math.ceil(width), (int)Math.ceil(height), rasterFormat);
+		Graphics2D imageGraphics = image.createGraphics();
+		imageGraphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+		imageGraphics.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
+		imageGraphics.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
+		imageGraphics.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
+
+		DrawingContext context =
+			new DrawingContext(imageGraphics);
+
+		Iterator<ImageWriter> writers =
+			ImageIO.getImageWritersByMIMEType(getMimeType());
+		if (writers.hasNext()) {
+			ImageWriter writer = writers.next();
+			ImageOutputStream ios =
+				ImageIO.createImageOutputStream(destination);
+			writer.setOutput(ios);
+			Rectangle2D boundsOld = d.getBounds();
+			d.setBounds(x, y, width, height);
+			try {
+				d.draw(context);
+				writer.write(image);
+			} finally {
+				d.setBounds(boundsOld);
+				ios.close();
+			}
+		}
+	}
+
+	/**
+	 * Returns the output format of this writer.
+	 * @return String representing the MIME-Type.
+	 */
+	public String getMimeType() {
+		return this.mimeType;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/plots/DrawableWriter.java

@@ -0,0 +1,44 @@
+package org.xbib.graphics.graph.gral.io.plots;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+
+/**
+ * Interface providing functions for rendering {@code Drawable}
+ * instances and writing them to an output stream. As an example: a plot
+ * can be saved into a bitmap file.
+ * @see DrawableWriterFactory
+ */
+public interface DrawableWriter {
+	/**
+	 * Returns the output format of this writer.
+	 * @return String representing the MIME-Type.
+	 */
+	String getMimeType();
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	void write(Drawable d, OutputStream destination,
+			   double width, double height) throws IOException;
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param x Horizontal position.
+	 * @param y Vertical position.
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	void write(Drawable d, OutputStream destination,
+			   double x, double y, double width, double height) throws IOException;
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/plots/DrawableWriterFactory.java

@@ -0,0 +1,73 @@
+package org.xbib.graphics.graph.gral.io.plots;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.text.MessageFormat;
+
+import org.xbib.graphics.graph.gral.io.AbstractIOFactory;
+
+/**
+ * <p>Class that provides {@code DrawableWriter} implementations for
+ * different file formats.</p>
+ *
+ * <p>Example Usage:</p>
+ * <pre>
+ * DrawableWriterFactory factory = DrawableWriterFactory.getInstance();
+ * DrawableWriter writer = factory.get("application/pdf");
+ * writer.write(plot, new FileOutputStream(filename));
+ * </pre>
+ *
+ * @see DrawableWriter
+ */
+public final class DrawableWriterFactory extends AbstractIOFactory<DrawableWriter> {
+	/** Singleton instance. */
+	private static DrawableWriterFactory instance;
+
+	/**
+	 * Constructor that initializes the factory.
+	 * @throws IOException if the properties file could not be found.
+	 */
+	private DrawableWriterFactory() throws IOException {
+		super("drawablewriters.properties"); //$NON-NLS-1$
+	}
+
+	/**
+	 * Returns an instance of this DrawableWriterFactory.
+	 * @return Instance.
+	 */
+	public static DrawableWriterFactory getInstance() {
+		if (instance == null) {
+			try {
+				instance = new DrawableWriterFactory();
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+		}
+		return instance;
+	}
+
+	@Override
+	public DrawableWriter get(String mimeType) {
+		DrawableWriter writer = null;
+		Class<? extends DrawableWriter> clazz = getTypeClass(mimeType);
+		//IOCapabilities capabilities = getCapabilities(mimeType);
+		try {
+			if (clazz != null) {
+				Constructor<? extends DrawableWriter> constructor =
+					clazz.getDeclaredConstructor(String.class);
+				writer = constructor.newInstance(mimeType);
+			}
+		} catch (SecurityException | InvocationTargetException | IllegalAccessException | InstantiationException | IllegalArgumentException | NoSuchMethodException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+
+		if (writer == null) {
+			throw new IllegalArgumentException(MessageFormat.format(
+					"Unsupported MIME type: {0}", mimeType)); //$NON-NLS-1$
+		}
+
+		return writer;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/io/plots/VectorWriter.java

@@ -0,0 +1,166 @@
+package org.xbib.graphics.graph.gral.io.plots;
+
+import java.awt.Graphics2D;
+import java.awt.geom.Rectangle2D;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.reflect.InvocationTargetException;
+import java.text.MessageFormat;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext.Quality;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext.Target;
+import org.xbib.graphics.graph.gral.io.IOCapabilities;
+import org.xbib.graphics.graph.gral.io.IOCapabilitiesStorage;
+import org.xbib.graphics.graph.gral.util.Messages;
+
+/**
+ * <p>Class that stores {@code Drawable} instances as vector graphics.
+ * This implementation requires the <i>VectorGraphics2D</i> library to provide
+ * support for the following file formats:</p>
+ * <ul>
+ *   <li>Encapsulated PostScript (EPS)</li>
+ *   <li>Portable Document Format (PDF)</li>
+ *   <li>Scalable Vector Graphics (SVG)</li>
+ * </ul>
+ *
+ * <p>If the <i>VectorGraphics2D</i> library isn't available the file formats
+ * aren't registered in the plug-in system. This class shouldn't be used directly
+ * but using the {@link DrawableWriterFactory}.</p>
+ */
+public class VectorWriter extends IOCapabilitiesStorage
+		implements DrawableWriter {
+	/** Mapping of MIME type string to {@code Processor} implementation. */
+	private static final Map<String, String> processors;
+	/** Java package that contains the VecorGraphics2D package. */
+	private static final String VECTORGRAPHICS2D_PACKAGE =
+		"de.erichseifert.vectorgraphics2d"; //$NON-NLS-1$
+
+	static {
+		processors = new HashMap<>();
+
+		addCapabilities(new IOCapabilities(
+			"EPS", //$NON-NLS-1$
+			Messages.getString("ImageIO.epsDescription"), //$NON-NLS-1$
+			"application/postscript", //$NON-NLS-1$
+			new String[] {"eps", "epsf", "epsi"} //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+		));
+		processors.put("application/postscript", "eps"); //$NON-NLS-1$ //$NON-NLS-2$
+
+		addCapabilities(new IOCapabilities(
+			"PDF", //$NON-NLS-1$
+			Messages.getString("ImageIO.pdfDescription"), //$NON-NLS-1$
+			"application/pdf", //$NON-NLS-1$
+			new String[] {"pdf"} //$NON-NLS-1$
+		));
+		processors.put("application/pdf", "pdf"); //$NON-NLS-1$ //$NON-NLS-2$
+
+		addCapabilities(new IOCapabilities(
+			"SVG", //$NON-NLS-1$
+			Messages.getString("ImageIO.svgDescription"), //$NON-NLS-1$
+			"image/svg+xml", //$NON-NLS-1$
+			new String[] {"svg", "svgz"} //$NON-NLS-1$ //$NON-NLS-2$
+		));
+		processors.put("image/svg+xml", "svg"); //$NON-NLS-1$ //$NON-NLS-2$
+	}
+
+	/** Current data format as MIME type string. */
+	private final String mimeType;
+
+	/**
+	 * Creates a new {@code VectorWriter} object with the specified
+	 * MIME-Type.
+	 * @param mimeType Output MIME-Type.
+	 */
+	@SuppressWarnings("unchecked")
+	protected VectorWriter(String mimeType) {
+		this.mimeType = mimeType;
+		if (!processors.containsKey(mimeType)) {
+			throw new IllegalArgumentException(MessageFormat.format(
+				"Unsupported file format: {0}", mimeType)); //$NON-NLS-1$
+		}
+	}
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	public void write(Drawable d, OutputStream destination,
+			double width, double height) throws IOException {
+		write(d, destination, 0.0, 0.0, width, height);
+	}
+
+	/**
+	 * Stores the specified {@code Drawable} instance.
+	 * @param d {@code Drawable} to be written.
+	 * @param destination Stream to write to
+	 * @param x Horizontal position.
+	 * @param y Vertical position.
+	 * @param width Width of the image.
+	 * @param height Height of the image.
+	 * @throws IOException if writing to stream fails
+	 */
+	public void write(Drawable d, OutputStream destination,
+			double x, double y, double width, double height)
+			throws IOException {
+		// Temporary change size of drawable
+		Rectangle2D boundsOld = d.getBounds();
+		d.setBounds(x, y, width, height);
+
+		try {
+			// Create an instance of Graphics2D implementation
+			Class<?> vg2dClass = Class.forName(VECTORGRAPHICS2D_PACKAGE +
+					".VectorGraphics2D"); //$NON-NLS-1$
+			Graphics2D g = (Graphics2D) vg2dClass.getDeclaredConstructor().newInstance();
+			// Paint the Drawable instance
+			d.draw(new DrawingContext(g, Quality.QUALITY, Target.VECTOR));
+			// Get sequence of commands
+			Class<?> commandSequenceClass = Class.forName(VECTORGRAPHICS2D_PACKAGE +
+					".intermediate.CommandSequence");  //$NON-NLS-1$
+			Object commands = vg2dClass.getMethod("getCommands").invoke(g); //$NON-NLS-1$
+			// Define page size
+			Class<?> pageSizeClass = Class.forName(VECTORGRAPHICS2D_PACKAGE +
+					".util.PageSize"); //$NON-NLS-1$
+			Object pageSize = pageSizeClass
+					.getConstructor(Double.TYPE, Double.TYPE, Double.TYPE, Double.TYPE)
+					.newInstance(x, y, width, height);
+			// Get the corresponding VectorGraphics2D processor instance
+			Class<?> processorsClass = Class.forName(VECTORGRAPHICS2D_PACKAGE +
+					".Processors");  //$NON-NLS-1$
+			Object processor = processorsClass.getMethod("get", String.class) //$NON-NLS-1$
+					.invoke(null, processors.get(mimeType));
+			Class<?> processorClass = processor.getClass();
+			// Get document from commands with defined page size
+			Object document = processorClass
+					.getMethod("getDocument", commandSequenceClass, pageSizeClass) //$NON-NLS-1$
+					.invoke(processor, commands, pageSize);
+			// Write document to destination stream
+			Class<?> documentClass = Class.forName(VECTORGRAPHICS2D_PACKAGE +
+					".Document"); //$NON-NLS-1$
+			documentClass.getMethod("writeTo", OutputStream.class) //$NON-NLS-1$
+					.invoke(document, destination);
+		} catch (ClassNotFoundException | SecurityException | InvocationTargetException |
+				IllegalAccessException | InstantiationException | IllegalArgumentException |
+				NoSuchMethodException e) {
+			throw new IllegalStateException(e);
+		} finally {
+			d.setBounds(boundsOld);
+		}
+	}
+
+	/**
+	 * Returns the output format of this writer.
+	 * @return String representing the MIME-Type.
+	 */
+	public String getMimeType() {
+		return mimeType;
+	}
+
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/AbstractNavigator.java

@@ -0,0 +1,290 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * Abstract base class that can be used to control the zoom and panning of an
+ * object. The navigator translates actions to operations on the object.
+ * The class provides implementations for zooming using a zoom factor,
+ * management of listeners, getting and setting a main direction for actions,
+ * and synchronizing actions with another navigator.
+ *
+ * Derived classes must use the methods
+ * {@link #fireCenterChanged(NavigationEvent)} and
+ * {@link #fireZoomChanged(NavigationEvent)} to notify listeners of changes to
+ * the center or zoom level. To avoid loop states these methods must only be
+ * called if a value has really been changed.
+ */
+public abstract class AbstractNavigator implements Navigator {
+	/** Default zoom factor. */
+	public static final double DEFAULT_ZOOM_FACTOR = 1.25;
+	/** Default minimum of zoom factor. */
+	public static final double DEFAULT_ZOOM_MIN = 1e-2;
+	/** Default maximum of zoom factor. */
+	public static final double DEFAULT_ZOOM_MAX = 1e+2;
+
+	/** Object that will be notified on navigation actions. */
+	private final Set<NavigationListener> navigationListeners;
+
+	/** Zoom factor used for zoom in and zoom out actions. */
+	private double zoomFactor;
+	/** Minimum allowed zoom level. */
+	private double zoomMin;
+	/** Maximum allowed zoom level. */
+	private double zoomMax;
+
+	/** A flag that tells whether to zoom the associated object. */
+	private boolean zoomable;
+	/** A flag that tells whether to pan the associated object. */
+	private boolean pannable;
+	/** The current navigation direction. */
+	private NavigationDirection direction;
+
+	/**
+	 * Initializes a new instance that is responsible for zooming and panning
+	 * the axes with the specified names of the specified plot.
+	 */
+	public AbstractNavigator() {
+		navigationListeners = new HashSet<>();
+		zoomFactor = DEFAULT_ZOOM_FACTOR;
+		zoomMin = DEFAULT_ZOOM_MIN;
+		zoomMax = DEFAULT_ZOOM_MAX;
+		zoomable = true;
+		pannable = true;
+	}
+
+	/**
+	 * Returns whether the associated object can be zoomed.
+	 * @return {@code true} if the object can be zoomed,
+	 *         {@code false} otherwise.
+	 */
+	public boolean isZoomable() {
+		return zoomable;
+	}
+
+	/**
+	 * Sets whether the associated object can be zoomed.
+	 * @param zoomable A value that tells whether it should be possible to zoom
+	 *        the associated object.
+	 */
+	public void setZoomable(boolean zoomable) {
+		this.zoomable = zoomable;
+	}
+
+	/**
+	 * Increases the current zoom level by the specified zoom factor.
+	 */
+	public void zoomIn() {
+		zoomInAt(null);
+	}
+
+	/**
+	 * Decreases the current zoom level by the specified zoom factor.
+	 */
+	public void zoomOut() {
+		zoomOutAt(null);
+	}
+
+	@Override
+	public void zoomAt(double zoom, PointND<? extends Number> zoomPoint) {
+		if (!isZoomable()) {
+			return;
+		}
+		boolean pan = isPannable() && zoomPoint != null;
+
+		PointND<? extends Number> center = null;
+		if (pan) {
+			center = getCenter();
+			setCenter(zoomPoint);
+		}
+		setZoom(zoom);
+		if (pan) {
+			setCenter(center);
+		}
+	}
+
+	@Override
+	public void zoomInAt(PointND<? extends Number> zoomPoint) {
+		double zoom = getZoom();
+		zoomAt(zoom*getZoomFactor(), zoomPoint);
+	}
+
+	@Override
+	public void zoomOutAt(PointND<? extends Number> zoomPoint) {
+		double zoom = getZoom();
+		zoomAt(zoom/getZoomFactor(), zoomPoint);
+	}
+
+	/**
+	 * Returns whether the associated object can be panned.
+	 * @return {@code true} if the object can be panned,
+	 *         {@code false} otherwise.
+	 */
+	public boolean isPannable() {
+		return pannable;
+	}
+
+	/**
+	 * Sets whether the associated object can be panned.
+	 * @param pannable A value that tells whether it should be possible to pan
+	 *        the associated object.
+	 */
+	public void setPannable(boolean pannable) {
+		this.pannable = pannable;
+	}
+
+	/**
+	 * Returns the factor which is used to change the zoom level on
+	 * zoom in/out actions.
+	 * @return The current zoom factor.
+	 */
+	public double getZoomFactor() {
+		return zoomFactor;
+	}
+	/**
+	 * Sets the factor which should be used to change the zoom level on
+	 * zoom in/out actions.
+	 * @param factor The new zoom factor.
+	 */
+	public void setZoomFactor(double factor) {
+		zoomFactor = factor;
+	}
+
+	/**
+	 * Returns the minimal zoom factor.
+	 * @return Minimal zoom factor.
+	 */
+	public double getZoomMin() {
+		return zoomMin;
+	}
+	/**
+	 * Sets the minimal zoom factor.
+	 * @param min New minimal zoom factor.
+	 */
+	public void setZoomMin(double min) {
+		this.zoomMin = min;
+	}
+
+	/**
+	 * Returns the minimal zoom factor.
+	 * @return Maximal zoom factor.
+	 */
+	public double getZoomMax() {
+		return zoomMax;
+	}
+	/**
+	 * Sets the maximal zoom factor.
+	 * @param max New maximal zoom factor.
+	 */
+	public void setZoomMax(double max) {
+		this.zoomMax = max;
+	}
+
+	/**
+	 * Adds the specified listener object that gets notified on changes to
+	 * navigation information like panning or zooming.
+	 * @param l Listener object
+	 */
+	public void addNavigationListener(NavigationListener l) {
+		navigationListeners.add(l);
+	}
+
+	/**
+	 * Removes the specified listener object, i.e. it doesn't get notified on
+	 * changes to navigation information like panning or zooming.
+	 * @param l Listener object
+	 */
+	public void removeNavigationListener(NavigationListener l) {
+		navigationListeners.remove(l);
+	}
+
+	/**
+	 * Returns the current direction of the components that will be taken into
+	 * account for zooming and panning.
+	 * @return Direction.
+	 */
+	public NavigationDirection getDirection() {
+		return direction;
+	}
+
+	/**
+	 * Sets the direction of the components that will be taken into account for
+	 * zooming and panning.
+	 * @param direction Direction.
+	 */
+	public void setDirection(NavigationDirection direction) {
+		this.direction = direction;
+	}
+
+	/**
+	 * Couples the actions of the current and the specified navigator. All
+	 * actions applied to this navigator will be also applied to the specified
+	 * navigator and vice versa.
+	 * @param navigator Navigator which should be bound to this instance.
+	 */
+	public void connect(Navigator navigator) {
+		if (navigator != null && navigator != this) {
+			addNavigationListener(navigator);
+			navigator.addNavigationListener(this);
+		}
+	}
+
+	/**
+	 * Decouples the actions of the current and the connected specified
+	 * navigator. All actions will be applied separately to each navigator.
+	 * @param navigator Navigator to be bound to this instance.
+	 */
+	public void disconnect(Navigator navigator) {
+		if (navigator != null && navigator != this) {
+			removeNavigationListener(navigator);
+			navigator.removeNavigationListener(this);
+		}
+	}
+
+	/**
+	 * A method that gets called after the center of an object in a connected
+	 * {@code PlotNavigator} has changed.
+	 * @param event An object describing the change event.
+	 */
+	public void centerChanged(NavigationEvent<PointND<? extends Number>> event) {
+		if (event.getSource() != this) {
+			setCenter(event.getValueNew());
+		}
+	}
+
+	/**
+	 * A method that gets called after the zoom level of an object in a
+	 * connected {@code PlotNavigator} has changed.
+	 * @param event An object describing the change event.
+	 */
+	public void zoomChanged(NavigationEvent<Double> event) {
+		if (event.getSource() != this) {
+			setZoom(event.getValueNew());
+		}
+	}
+
+	/**
+	 * Notifies all navigation listeners that the center of one or more
+	 * components have been changed.
+	 * @param event An object describing the change event.
+	 */
+	protected void fireCenterChanged(NavigationEvent<PointND<? extends Number>> event) {
+		for (NavigationListener l : navigationListeners) {
+			l.centerChanged(event);
+		}
+	}
+
+	/**
+	 * Notifies all navigation listeners that the zoom level of all components
+	 * has been changed.
+	 * @param event An object describing the change event.
+	 */
+	protected void fireZoomChanged(NavigationEvent<Double> event) {
+		for (NavigationListener l : navigationListeners) {
+			l.zoomChanged(event);
+		}
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/Navigable.java

@@ -0,0 +1,13 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+/**
+ * Interface for classes that can provide a {@code Navigator} which translates
+ * navigational actions.
+ */
+public interface Navigable {
+	/**
+	 * Returns a navigator instance that can control the current object.
+	 * @return A navigator instance.
+	 */
+	Navigator getNavigator();
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/NavigationDirection.java

@@ -0,0 +1,8 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+/**
+ * Marker interface for implementation specific navigation direction,
+ * such as horizontal, vertical for two dimensional objects.
+ */
+public interface NavigationDirection {
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/NavigationEvent.java

@@ -0,0 +1,51 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+/**
+ * Data class that describes a navigational event, like zooming or panning.
+ *
+ * @param <T> Data type of the value that has been changed.
+ */
+public class NavigationEvent<T> {
+	/** Object that has caused the change. */
+	private final Navigator source;
+	/** Value before the change. */
+	private final T valueOld;
+	/** Value after the change. */
+	private final T valueNew;
+
+	/**
+	 * Initializes a new instance.
+	 * @param source Navigator object that has caused the change.
+	 * @param valueOld Value before the change
+	 * @param valueNew Value after the change.
+	 */
+	public NavigationEvent(Navigator source, T valueOld, T valueNew) {
+		this.source = source;
+		this.valueOld = valueOld;
+		this.valueNew = valueNew;
+	}
+
+	/**
+	 * Returns the navigator that has caused the change.
+	 * @return Navigator object that has caused the change.
+	 */
+	public Navigator getSource() {
+		return source;
+	}
+
+	/**
+	 * Returns the value before the change.
+	 * @return Value before the change.
+	 */
+	public T getValueOld() {
+		return valueOld;
+	}
+
+	/**
+	 * Returns the value after the change.
+	 * @return Value after the change.
+	 */
+	public T getValueNew() {
+		return valueNew;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/NavigationListener.java

@@ -0,0 +1,25 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * An interface for classes that want to be notified on navigation changes like
+ * panning or zooming.
+ *
+ * @see Navigator
+ */
+public interface NavigationListener {
+	/**
+	 * A method that gets called after the center of an object in the
+	 * {@code PlotNavigator} has changed.
+	 * @param event An object describing the change event.
+	 */
+	void centerChanged(NavigationEvent<PointND<? extends Number>> event);
+
+	/**
+	 * A method that gets called after the zoom level of an object in the
+	 * {@code PlotNavigator} has changed.
+	 * @param event An object describing the change event.
+	 */
+	void zoomChanged(NavigationEvent<Double> event);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/navigation/Navigator.java

@@ -0,0 +1,227 @@
+package org.xbib.graphics.graph.gral.navigation;
+
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * An interface for translating navigational interactions, such as zooming
+ * panning to control the associated {@link Navigable} object. At the moment
+ * the only supported operations are zooming and panning.
+ *
+ * A navigator stores an default state of the object that can be used to reset
+ * the object's state after actions have been performed. This must be
+ * implemented with the methods {@link #setDefaultState()} and
+ * {@link #reset()}.
+ *
+ * Zooming and panning may be activated and deactivated using the methods
+ * {@link #setZoomable(boolean)} and {@link #setPannable(boolean)}.
+ *
+ * Additionally, the actions can also be bound to a certain direction—like
+ * horizontal or vertical—by the convenience methods {@link #getDirection()}
+ * and {@link #setDirection(NavigationDirection)}. The data type, e.g. an enum
+ * type, for directions must implement the interface
+ * {@link NavigationDirection}.
+ *
+ * Sometimes, actions performed on an object should be applied to another
+ * object synchronously. The methods {@link #connect(Navigator)} and
+ * {@link #disconnect(Navigator)} may be implemented to provide functionality
+ * for this use case.
+ */
+public interface Navigator extends NavigationListener {
+	/**
+	 * Returns whether the associated object can be zoomed.
+	 * @return {@code true} if the object can be zoomed,
+	 *         {@code false} otherwise.
+	 */
+	boolean isZoomable();
+
+	/**
+	 * Sets whether the associated object can be zoomed.
+	 * @param zoomable A value that tells whether it should be possible to zoom
+	 *        the associated object.
+	 */
+	void setZoomable(boolean zoomable);
+
+	/**
+	 * Returns the current zoom level of the associated object.
+	 * @return Current zoom level.
+	 */
+	double getZoom();
+
+	/**
+	 * Sets the zoom level of the associated object to the specified value.
+	 * @param zoom New zoom level.
+	 */
+	void setZoom(double zoom);
+
+	/**
+	 * Increases the current zoom level by the specified zoom factor.
+	 * The zoom will only be changed if the navigator is zoomable.
+	 *
+	 * @see #isZoomable()
+	 * @see #setZoomable(boolean)
+	 */
+	void zoomIn();
+
+	/**
+	 * Decreases the current zoom level by the specified zoom factor.
+	 * The zoom will only be changed if the navigator is zoomable.
+	 *
+	 * @see #isZoomable()
+	 * @see #setZoomable(boolean)
+	 */
+	void zoomOut();
+
+	/**
+	 * Scale the associated object at the specified point. If zooming is disabled nothing will be done. If panning is
+	 * disabled zooming will be applied around the current center.
+	 * @param zoom New zoom level.
+	 * @param zoomPoint Center point for zooming in world units.
+	 */
+	void zoomAt(double zoom, PointND<? extends Number> zoomPoint);
+
+	/**
+	 * Increases the current zoom level by the specified zoom factor and scales
+	 * the associated object at the specified point.
+	 * @param zoomPoint Center point for zooming in world units.
+	 */
+	void zoomInAt(PointND<? extends Number> zoomPoint);
+
+	/**
+	 * Decreases the current zoom level by the specified zoom factor and scales
+	 * the associated object at the specified point.
+	 * @param zoomPoint Center point for zooming in world units.
+	 */
+	void zoomOutAt(PointND<? extends Number> zoomPoint);
+
+	/**
+	 * Returns whether the associated object can be panned.
+	 * @return {@code true} if the object can be panned,
+	 *         {@code false} otherwise.
+	 */
+	boolean isPannable();
+
+	/**
+	 * Sets whether the associated object can be panned.
+	 * @param pannable A value that tells whether it should be possible to pan
+	 *        the associated object.
+	 */
+	void setPannable(boolean pannable);
+
+	/**
+	 * Returns the current center point. The returned point contains value in
+	 * world units.
+	 * @return Center point in world units.
+	 */
+	PointND<? extends Number> getCenter();
+
+	/**
+	 * Sets a new center point. The values of the point are in world units.
+	 * The center point will only be changed if the navigator is pannable.
+	 * @param center New center point in world units.
+	 * @see #isPannable()
+	 * @see #setPannable(boolean)
+	 */
+	void setCenter(PointND<? extends Number> center);
+
+	/**
+	 * Moves the center by the relative values of the specified point.
+	 * The values of the point are in screen units.
+	 * The center point will only be changed if the navigator is pannable.
+	 * @param deltas Relative values to use for panning.
+	 * @see #isPannable()
+	 * @see #setPannable(boolean)
+	 */
+	void pan(PointND<? extends Number> deltas);
+
+	/**
+	 * Sets the current state as the default state of the object.
+	 * Resetting the navigator will then return to the default state.
+	 */
+	void setDefaultState();
+
+	/**
+	 * Sets the object's position and zoom level to the default state.
+	 */
+	void reset();
+
+	/**
+	 * Returns the factor which is used to change the zoom level on
+	 * zoom in/out actions.
+	 * @return The current zoom factor.
+	 */
+	double getZoomFactor();
+
+	/**
+	 * Sets the factor which should be used to change the zoom level on
+	 * zoom in/out actions.
+	 * @param factor The new zoom factor.
+	 */
+	void setZoomFactor(double factor);
+
+	/**
+	 * Returns the minimal zoom factor.
+	 * @return Minimal zoom factor.
+	 */
+	double getZoomMin();
+
+	/**
+	 * Sets the minimal zoom factor.
+	 * @param min New minimal zoom factor.
+	 */
+	void setZoomMin(double min);
+
+	/**
+	 * Returns the minimal zoom factor.
+	 * @return Maximal zoom factor.
+	 */
+	double getZoomMax();
+
+	/**
+	 * Sets the maximal zoom factor.
+	 * @param max New maximal zoom factor.
+	 */
+	void setZoomMax(double max);
+
+	/**
+	 * Adds the specified listener object that gets notified on changes to
+	 * navigation information like panning or zooming.
+	 * @param l Listener object
+	 */
+	void addNavigationListener(NavigationListener l);
+
+	/**
+	 * Removes the specified listener object, i.e. it doesn't get notified on
+	 * changes to navigation information like panning or zooming.
+	 * @param l Listener object
+	 */
+	void removeNavigationListener(NavigationListener l);
+
+	/**
+	 * Returns the current direction of the components that will be taken into
+	 * account for zooming and panning.
+	 * @return Direction.
+	 */
+	NavigationDirection getDirection();
+
+	/**
+	 * Sets the direction of the components that will be taken into account for
+	 * zooming and panning.
+	 * @param direction Direction.
+	 */
+	void setDirection(NavigationDirection direction);
+
+	/**
+	 * Couples the actions of the current and the specified navigator. All
+	 * actions applied to this navigator will be also applied to the specified
+	 * navigator and vice versa.
+	 * @param navigator Navigator which should be bound to this instance.
+	 */
+	void connect(Navigator navigator);
+
+	/**
+	 * Decouples the actions of the current and the connected specified
+	 * navigator. All actions will be applied separately to each navigator.
+	 * @param navigator Navigator to be unbound from this instance.
+	 */
+	void disconnect(Navigator navigator);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/AbstractPlot.java

@@ -0,0 +1,835 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Stroke;
+import java.awt.geom.Rectangle2D;
+import java.text.MessageFormat;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+import org.xbib.graphics.graph.gral.data.Column;
+import org.xbib.graphics.graph.gral.data.DataChangeEvent;
+import org.xbib.graphics.graph.gral.data.DataListener;
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawableContainer;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.graphics.layout.EdgeLayout;
+import org.xbib.graphics.graph.gral.graphics.Label;
+import org.xbib.graphics.graph.gral.graphics.layout.OuterEdgeLayout;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.plots.legends.Legend;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.graphics.Location;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+/**
+ * Basic implementation of a plot that can listen to changes of data sources
+ * and settings.
+ */
+public abstract class AbstractPlot extends DrawableContainer
+		implements Plot, DataListener {
+
+	/** Default size of the plot title relative to the size of the base font. */
+	private static final float DEFAULT_TITLE_FONT_SIZE = 1.5f;
+	/** Default space between layout components relative to the size of the base font. */
+	private static final float DEFAULT_LAYOUT_GAP = 2f;
+
+	/** Data sources. */
+	private final List<DataSource> data;
+	/** Set of all data sources that are visible (not hidden). */
+	private final Set<DataSource> dataVisible;
+
+	/** Mapping of axis names to axis objects. */
+	private final Map<String, Axis> axes;
+	/** Mapping of axis names to axis renderer objects. */
+	private final Map<String, AxisRenderer> axisRenderers;
+	/** Mapping of axis names to drawable objects. */
+	private final Map<String, Drawable> axisDrawables;
+
+	/** Mapping of data source columns to axes. **/
+	private final Map<DataSource, Map<Integer, String>> columnToAxisMappingByDataSource;
+	/** Minimum values of axes. **/
+	private final Map<String, Double> axisMin;
+	/** Maximum values of axes. **/
+	private final Map<String, Double> axisMax;
+
+	/** Title text of the plot. */
+	private final Label title;
+	/** AbstractPlot area used to render the data. */
+	private PlotArea plotArea;
+	/** Container that will store and layout the plot legend. */
+	private final Container legendContainer;
+	/** AbstractPlot legend. */
+	private Legend legend;
+
+	/** Paint to fill the plot background. */
+	private Paint background;
+	/** Stroke to draw the plot border. */
+	private transient Stroke borderStroke;
+	/** Paint to fill the plot border. */
+	private Paint borderColor;
+
+	/** Base font which is used as default for other elements of the plot and
+	for calculation of relative sizes. */
+	private Font font;
+
+	/** Decides whether a legend will be shown. */
+	private boolean legendVisible;
+	/** Positioning of the legend. */
+	private Location legendLocation;
+	/** Distance of the legend to the plot area. */
+	private double legendDistance;
+
+	/**
+	 * Initializes a new {@code AbstractPlot} instance with the specified data series.
+	 * The series will be visible by default.
+	 * @param series Initial data series to be displayed.
+	 */
+	public AbstractPlot(DataSource... series) {
+		super(new EdgeLayout());
+
+		dataVisible = new HashSet<>();
+
+		axes = new HashMap<>();
+		axisRenderers = new HashMap<>();
+		axisDrawables = new HashMap<>();
+
+		columnToAxisMappingByDataSource = new HashMap<>();
+		axisMin = new HashMap<>();
+		axisMax = new HashMap<>();
+
+		data = new LinkedList<>();
+		for (DataSource source : series) {
+			add(source);
+		}
+
+		// No background or border by default
+		background = null;
+		borderStroke = null;
+		borderColor = Color.BLACK;
+
+		// Use system standard font as base font
+		font = Font.decode(null);
+		updateBaseFont();
+
+		// Create title
+		title = new Label();
+		title.setFont(font.deriveFont(DEFAULT_TITLE_FONT_SIZE*font.getSize2D()));
+		add(title, Location.NORTH);
+
+		// Create legend, but don't show it by default
+		legendContainer = new DrawableContainer(new OuterEdgeLayout(0.0));
+		legendLocation = Location.CENTER;
+		legendDistance = 2.0;
+		legendVisible = false;
+		refreshLegendLayout();
+	}
+
+	/**
+	 * Draws the {@code Drawable} with the specified drawing context.
+	 * @param context Environment used for drawing
+	 */
+	@Override
+	public void draw(DrawingContext context) {
+		Graphics2D graphics = context.getGraphics();
+
+		Paint bg = getBackground();
+		if (bg != null) {
+			GraphicsUtils.fillPaintedShape(graphics, getBounds(), bg, null);
+		}
+
+		Stroke stroke = getBorderStroke();
+		if (stroke != null) {
+			Paint fg = getBorderColor();
+			GraphicsUtils.drawPaintedShape(
+					graphics, getBounds(), fg, null, stroke);
+		}
+
+		drawComponents(context);
+	}
+
+	/**
+	 * Draws the plot's axes into the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	protected void drawAxes(DrawingContext context) {
+		for (Drawable d : axisDrawables.values()) {
+			if (d != null) {
+				d.draw(context);
+			}
+		}
+	}
+
+	/**
+	 * Draws the plot's legend into the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	protected void drawLegend(DrawingContext context) {
+		if (!isLegendVisible() || getLegend() == null) {
+			return;
+		}
+		getLegend().draw(context);
+	}
+
+	@Override
+	public void layout() {
+		super.layout();
+		layoutAxes();
+		layoutLegend();
+	}
+
+	/**
+	 * Calculates the bounds of the axes.
+	 */
+	protected void layoutAxes() {
+	}
+
+	/**
+	 * Calculates the bounds of the legend component.
+	 */
+	protected void layoutLegend() {
+		if (getPlotArea() == null) {
+			return;
+		}
+		Container legendContainer = getLegendContainer();
+		Rectangle2D plotBounds = getPlotArea().getBounds();
+		legendContainer.setBounds(plotBounds);
+	}
+
+	/**
+	 * Returns the axis with the specified name.
+	 * @param name Name of the axis.
+	 * @return Axis.
+	 */
+	public Axis getAxis(String name) {
+		return axes.get(name);
+	}
+
+	/**
+	 * Sets the axis with the specified name and the associated
+	 * {@code AxisRenderer}.
+	 * @param name Name of the axis.
+	 * @param axis Axis.
+	 */
+	public void setAxis(String name, Axis axis) {
+		if (axis == null) {
+			removeAxis(name);
+		} else {
+			axes.put(name, axis);
+		}
+	}
+
+	/**
+	 * Removes the axis with the specified name.
+	 * @param name Name of the axis to be removed.
+	 */
+	public void removeAxis(String name) {
+		axes.remove(name);
+		axisRenderers.remove(name);
+		axisDrawables.remove(name);
+	}
+
+	/**
+	 * Returns a collection of all names of the axes stored in this plot.
+	 * @return The names of all axes stored in this plot.
+	 */
+	public Collection<String> getAxesNames() {
+		return axes.keySet();
+	}
+
+	/**
+	 * Creates all axes that are defined by the current plot type.
+	 */
+	protected void createDefaultAxes() {
+	}
+
+	/**
+	 * Creates all axis renderers that are defined by the current plot type.
+	 */
+	protected void createDefaultAxisRenderers() {
+	}
+
+	/**
+	 * Tries to automatically set the ranges of all axes that are set to auto-scale.
+	 * @see Axis#setAutoscaled(boolean)
+	 */
+	protected void autoscaleAxes() {
+		if (data.isEmpty()) {
+			return;
+		}
+		for (String axisName : getAxesNames()) {
+			autoscaleAxis(axisName);
+		}
+	}
+
+	/**
+	 * Tries to automatically set the ranges of the axes specified by the name
+	 * if it is set to auto-scale.
+	 * @param axisName Name of the axis that should be scaled.
+	 * @see Axis#setAutoscaled(boolean)
+	 */
+	public void autoscaleAxis(String axisName) {
+		Axis axis = getAxis(axisName);
+		if (axis == null || !axis.isAutoscaled()) {
+			return;
+		}
+		double min = getAxisMin(axisName);
+		double max = getAxisMax(axisName);
+		double margin = 0.0*(max - min);
+		axis.setRange(min - margin, max + margin);
+	}
+
+	/**
+	 * Returns the renderer for the axis with the specified name.
+	 * @param axisName Axis name.
+	 * @return Instance that renders the axis.
+	 */
+	public AxisRenderer getAxisRenderer(String axisName) {
+		return axisRenderers.get(axisName);
+	}
+
+	/**
+	 * Sets the renderer for the axis with the specified name.
+	 * @param axisName Name of the axis to be rendered.
+	 * @param renderer Instance to render the axis.
+	 */
+	public void setAxisRenderer(String axisName, AxisRenderer renderer) {
+		Drawable comp = null;
+		if (renderer == null) {
+			axisRenderers.remove(axisName);
+		} else {
+			axisRenderers.put(axisName, renderer);
+			Axis axis = getAxis(axisName);
+			comp = renderer.getRendererComponent(axis);
+		}
+		setAxisComponent(axisName, comp);
+		layout();
+	}
+
+	/**
+	 * Returns the component that is used to draw the specified axis.
+	 * @param axisName Name of the axis.
+	 * @return Instance that draws the axis.
+	 */
+	protected Drawable getAxisComponent(String axisName) {
+		return axisDrawables.get(axisName);
+	}
+
+	/**
+	 * Sets the component that should be used for drawing the specified axis.
+	 * @param axisName Name of the axis.
+	 * @param comp Instance that draws the axis.
+	 */
+	private void setAxisComponent(String axisName, Drawable comp) {
+		if (comp == null) {
+			axisDrawables.remove(axisName);
+		} else {
+			axisDrawables.put(axisName, comp);
+		}
+	}
+
+	/**
+	 * Returns the drawing area of this plot.
+	 * @return {@code PlotArea2D}.
+	 */
+	public PlotArea getPlotArea() {
+		return plotArea;
+	}
+
+	/**
+	 * Sets the drawing area to the specified value.
+	 * @param plotArea {@code PlotArea2D} to be set.
+	 */
+	protected void setPlotArea(PlotArea plotArea) {
+		if (this.plotArea != null) {
+			remove(this.plotArea);
+			this.plotArea.setBaseFont(null);
+		}
+		this.plotArea = plotArea;
+		if (this.plotArea != null) {
+			this.plotArea.setBaseFont(font);
+			add(this.plotArea, Location.CENTER);
+		}
+	}
+
+	/**
+	 * Returns the title component of this plot.
+	 * @return Label representing the title.
+	 */
+	public Label getTitle() {
+		return title;
+	}
+
+	/**
+	 * Returns the object containing the Legend.
+	 * @return Container.
+	 */
+	protected Container getLegendContainer() {
+		return legendContainer;
+	}
+
+	/**
+	 * Returns the legend component.
+	 * @return Legend.
+	 */
+	public Legend getLegend() {
+		return legend;
+	}
+
+	/**
+	 * Sets the legend to the specified value.
+	 * @param legend Legend to be set.
+	 */
+	protected void setLegend(Legend legend) {
+		if (this.legend != null) {
+			legendContainer.remove(this.legend);
+			this.legend.clear();
+			this.legend.setBaseFont(null);
+		}
+		this.legend = legend;
+		if (this.legend != null) {
+			this.legend.setBaseFont(font);
+			Location constraints = getLegendLocation();
+			legendContainer.add(legend, constraints);
+			for (DataSource source : getVisibleData()) {
+				legend.add(source);
+			}
+		}
+	}
+
+	/**
+	 * Refreshes the positioning and spacing of the legend.
+	 */
+	protected void refreshLegendLayout() {
+		double absoluteLegendDistance = 0.0;
+		if (MathUtils.isCalculatable(legendDistance)) {
+			absoluteLegendDistance = legendDistance*font.getSize2D();
+		}
+
+		OuterEdgeLayout layout = new OuterEdgeLayout(absoluteLegendDistance);
+		legendContainer.setLayout(layout);
+	}
+
+	@Override
+	public Paint getBackground() {
+		return background;
+	}
+
+	@Override
+	public void setBackground(Paint background) {
+		this.background = background;
+	}
+
+	@Override
+	public Stroke getBorderStroke() {
+		return borderStroke;
+	}
+
+	@Override
+	public void setBorderStroke(Stroke border) {
+		this.borderStroke = border;
+	}
+
+	@Override
+	public Paint getBorderColor() {
+		return borderColor;
+	}
+
+	@Override
+	public void setBorderColor(Paint color) {
+		this.borderColor = color;
+	}
+
+	@Override
+	public Font getFont() {
+		return font;
+	}
+
+	@Override
+	public void setFont(Font font) {
+		this.font = font;
+		updateBaseFont();
+	}
+
+	private void updateBaseFont() {
+		// Update layout
+		float gap = DEFAULT_LAYOUT_GAP*font.getSize2D();
+		getLayout().setGapX(gap);
+		getLayout().setGapY(gap);
+
+		// Update plot area
+		if (plotArea != null) {
+			plotArea.setBaseFont(font);
+		}
+
+		// Update legend
+		if (legend != null) {
+			legend.setBaseFont(font);
+		}
+	}
+
+	@Override
+	public boolean isLegendVisible() {
+		return legendVisible;
+	}
+
+	@Override
+	public void setLegendVisible(boolean legendVisible) {
+		this.legendVisible = legendVisible;
+	}
+
+	@Override
+	public Location getLegendLocation() {
+		return legendLocation;
+	}
+
+	@Override
+	public void setLegendLocation(Location location) {
+		legendLocation = location;
+		if (legend != null) {
+			legendContainer.remove(legend);
+			legendContainer.add(legend, legendLocation);
+		}
+	}
+
+	@Override
+	public double getLegendDistance() {
+		return legendDistance;
+	}
+
+	@Override
+	public void setLegendDistance(double distance) {
+		legendDistance = distance;
+		refreshLegendLayout();
+	}
+
+	/**
+	 * Adds a new data series to the plot which is visible by default.
+	 * @param source Data series.
+	 */
+	public void add(DataSource source) {
+		add(source, true);
+	}
+
+	/**
+	 * Adds a new data series to the plot.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be displayed,
+	 *        {@code false} otherwise.
+	 */
+	public void add(DataSource source, boolean visible) {
+		add(data.size(), source, visible);
+	}
+
+	/**
+	 * Inserts the specified data series to the plot at a specified position.
+	 * @param index Position.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be displayed,
+	 *        {@code false} otherwise.
+	 */
+	public void add(int index, DataSource source, boolean visible) {
+		data.add(index, source);
+		if (visible) {
+			dataVisible.add(source);
+		}
+		autoscaleAxes();
+		if (getLegend() != null) {
+			getLegend().add(source);
+		}
+		source.addDataListener(this);
+		invalidateAxisExtrema();
+	}
+
+	/**
+	 * Returns whether the plot contains the specified data series.
+	 * @param source Data series.
+	 * @return {@code true} if the specified element is stored in the
+	 *         plot, otherwise {@code false}
+	 */
+	public boolean contains(DataSource source) {
+		return data.contains(source);
+	}
+
+	/**
+	 * Returns the data series at a specified index.
+	 * @param index Position of the data series.
+	 * @return Instance of the data series.
+	 */
+	public DataSource get(int index) {
+		return data.get(index);
+	}
+
+	/**
+	 * Deletes the specified data series from the plot.
+	 * @param source Data series.
+	 * @return {@code true} if the series existed,
+	 *         otherwise {@code false}.
+	 */
+	public boolean remove(DataSource source) {
+		source.removeDataListener(this);
+		dataVisible.remove(source);
+		if (getLegend() != null) {
+			getLegend().remove(source);
+		}
+		boolean existed = data.remove(source);
+		invalidateAxisExtrema();
+		return existed;
+	}
+
+	/**
+	 * Removes all data series from this plot.
+	 */
+	public void clear() {
+		for (DataSource source : data) {
+			source.removeDataListener(this);
+		}
+		dataVisible.clear();
+		if (getLegend() != null) {
+			getLegend().clear();
+		}
+		data.clear();
+		invalidateAxisExtrema();
+	}
+
+	/**
+	 * Returns the mapping of a data source column to an axis name. If no
+	 * mapping exists {@code null} will be returned.
+	 * @param source Data source.
+	 * @param col Column index.
+	 * @return Axis name or {@code null} if no mapping exists.
+	 */
+	private String getMapping(DataSource source, int col) {
+		Map<Integer, String> columnToAxisMapping = columnToAxisMappingByDataSource.get(source);
+		return columnToAxisMapping != null ? columnToAxisMapping.get(col) : null;
+	}
+
+	/**
+	 * Returns the mapping of data source columns to axis names. The elements
+	 * of returned array equal the column indexes, i.e. the first element (axis
+	 * name) matches the first column of {@code source}. If no mapping exists
+	 * {@code null} will be stored in the array.
+	 * @param source Data source.
+	 * @return Array containing axis names in the order of the columns,
+	 *         or {@code null} if no mapping exists for the column.
+	 */
+	public String[] getMapping(DataSource source) {
+		String[] mapping = new String[source.getColumnCount()];
+		for (int col = 0; col < mapping.length; col++) {
+			mapping[col] = getMapping(source, col);
+		}
+		return mapping;
+	}
+
+	/**
+	 * Sets the mapping of data source columns to axis names. The column index
+	 * is taken from the order of the axis names, i.e. the first column of
+	 * {@code source} will be mapped to first element of {@code axisNames}.
+	 * Axis names with value {@code null} will be ignored.
+	 * @param source Data source.
+	 * @param axisNames Sequence of axis names in the order of the columns.
+	 */
+	public void setMapping(DataSource source, String... axisNames) {
+		if (!contains(source)) {
+			throw new IllegalArgumentException(
+				"Data source does not exist in plot."); //$NON-NLS-1$
+		}
+		if (axisNames.length > source.getColumnCount()) {
+			throw new IllegalArgumentException(MessageFormat.format(
+				"Data source only has {0,number,integer} column, {1,number,integer} values given.", //$NON-NLS-1$
+				source.getColumnCount(), axisNames.length));
+		}
+		Map<Integer, String> columnToAxisMapping = new HashMap<>();
+		for (int col = 0; col < axisNames.length; col++) {
+			String axisName = axisNames[col];
+			if (axisName != null) {
+				columnToAxisMapping.put(col, axisName);
+			}
+		}
+		columnToAxisMappingByDataSource.put(source, columnToAxisMapping);
+		invalidateAxisExtrema();
+	}
+
+	/**
+	 * Returns the minimum value of the axis specified by {@code axisName}.
+	 * @param axisName Name of the axis.
+	 * @return Minimum value for the specified axis, or {@code 0.0} if no
+	 *         minimum value can be determined.
+	 */
+	protected Double getAxisMin(String axisName) {
+		Double min = axisMin.get(axisName);
+		if (min == null) {
+			revalidateAxisExtrema();
+			min = axisMin.get(axisName);
+		}
+		if (min == null) {
+			min = 0.0;
+		}
+		return min;
+	}
+	/**
+	 * Returns the maximum value of the axis specified by {@code axisName}.
+	 * @param axisName Name of the axis.
+	 * @return Maximum value for the specified axis, or {@code 0.0} if no
+	 *         maximum value can be determined.
+	 */
+	protected Double getAxisMax(String axisName) {
+		Double max = axisMax.get(axisName);
+		if (max == null) {
+			revalidateAxisExtrema();
+			max = axisMax.get(axisName);
+		}
+		if (max == null) {
+			return 0.0;
+		}
+		return max;
+	}
+
+	/**
+	 * Returns a list of all data series stored in the plot.
+	 * @return List of all data series.
+	 */
+	public List<DataSource> getData() {
+		return Collections.unmodifiableList(data);
+	}
+
+	/**
+	 * Returns a list of all visible data series stored in the plot.
+	 * @return List of all visible data series.
+	 */
+	public List<DataSource> getVisibleData() {
+		List<DataSource> visible = new LinkedList<>();
+		for (DataSource s : data) {
+			if (dataVisible.contains(s)) {
+				visible.add(s);
+			}
+		}
+		return visible;
+	}
+
+	/**
+	 * Returns whether the specified data series is drawn.
+	 * @param source Data series.
+	 * @return {@code true} if visible, {@code false} otherwise.
+	 */
+	public boolean isVisible(DataSource source) {
+		return dataVisible.contains(source);
+	}
+
+	/**
+	 * Changes the visibility of the specified data series.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be visible,
+	 *        {@code false} otherwise.
+	 */
+	public void setVisible(DataSource source, boolean visible) {
+		if (visible) {
+			if (dataVisible.add(source)) {
+				invalidateAxisExtrema();
+			}
+		} else {
+			if (dataVisible.remove(source)) {
+				invalidateAxisExtrema();
+			}
+		}
+	}
+
+	/**
+	 * Method that is invoked when data has been added.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been added.
+	 */
+	public void dataAdded(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+	}
+
+	/**
+	 * Method that is invoked when data has been updated.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been updated.
+	 */
+	public void dataUpdated(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+	}
+
+	/**
+	 * Method that is invoked when data has been removed.
+	 * This method is invoked by objects that provide support for
+	 * {@code DataListener}s and should not be called manually.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been removed.
+	 */
+	public void dataRemoved(DataSource source, DataChangeEvent... events) {
+		dataChanged(source, events);
+	}
+
+	/**
+	 * Method that is invoked when data has been added, updated, or removed.
+	 * @param source Data source that has been changed.
+	 * @param events Optional event object describing the data values that
+	 *        have been changed.
+	 */
+	protected void dataChanged(DataSource source, DataChangeEvent... events) {
+		invalidateAxisExtrema();
+		autoscaleAxes();
+		layout();
+	}
+
+	/**
+	 * Causes cached plot data to be be updated.
+	 */
+	private void invalidateAxisExtrema() {
+		axisMin.clear();
+		axisMax.clear();
+	}
+
+	/**
+	 * Rebuilds cached plot data.
+	 */
+	private void revalidateAxisExtrema() {
+		synchronized (this) {
+			for (Entry<DataSource, Map<Integer, String>> entryByDataSource : columnToAxisMappingByDataSource.entrySet()) {
+				DataSource dataSource = entryByDataSource.getKey();
+				Map<Integer, String> columnToAxisMapping = entryByDataSource.getValue();
+				for (Entry<Integer, String> entry : columnToAxisMapping.entrySet()) {
+					Integer colIndex = entry.getKey();
+					String axisName = entry.getValue();
+
+					Column<?> col = dataSource.getColumn(colIndex);
+					Double min = axisMin.get(axisName);
+					Double max = axisMax.get(axisName);
+					if (min == null || max == null) {
+						min = col.getStatistics(Statistics.MIN);
+						max = col.getStatistics(Statistics.MAX);
+					} else {
+						min = Math.min(min, col.getStatistics(Statistics.MIN));
+						max = Math.max(max, col.getStatistics(Statistics.MAX));
+					}
+					axisMin.put(axisName, min);
+					axisMax.put(axisName, max);
+				}
+			}
+		}
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/BarPlot.java

@@ -0,0 +1,452 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Rectangle2D;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.Row;
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.graphics.Location;
+import org.xbib.graphics.graph.gral.plots.areas.AreaRenderer;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.plots.colors.ColorMapper;
+import org.xbib.graphics.graph.gral.plots.legends.AbstractLegend;
+import org.xbib.graphics.graph.gral.plots.legends.Legend;
+import org.xbib.graphics.graph.gral.plots.legends.ValueLegend;
+import org.xbib.graphics.graph.gral.plots.lines.LineRenderer;
+import org.xbib.graphics.graph.gral.plots.points.DefaultPointRenderer2D;
+import org.xbib.graphics.graph.gral.plots.points.PointData;
+import org.xbib.graphics.graph.gral.plots.points.PointRenderer;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * <p>Class that displays data in a bar plot.</p>
+ * <p>To create a new {@code BarPlot} simply create a new instance
+ * using one or more data sources. Example:</p>
+ * <pre>
+ * DataTable data = new DataTable(Integer.class, Double.class);
+ * data.add(2010, -5.00);
+ * data.add(2011,  3.25);
+ * data.add(2012, -0.50);
+ * data.add(2012,  4.00);
+ *
+ * BarPlot plot = new BarPlot(data);
+ * </pre>
+ */
+public class BarPlot extends XYPlot {
+
+	/** Relative width of the bars. 1.0 means the bars touch each other
+	 * without gap. */
+	private double barWidth;
+	/** Minimal height of the bars in pixels. */
+	private double barHeightMin;
+	/** Decides whether the bars should be filled as a whole, or each bar on
+	 * its own. This can e.g. be important for gradients. */
+	private boolean paintAllBars;
+
+	/**
+	 * Class that renders a bar in a bar plot.
+	 */
+	public static class BarRenderer extends DefaultPointRenderer2D {
+
+		/** Plot that contains settings and renderers. */
+		private final BarPlot plot;
+
+		/** Stroke to draw the border of the bar. */
+		// Custom serialization will be done with a wrapper object
+		private transient Stroke borderStroke;
+		/** Color to fill the border of the bar. */
+		private Paint borderColor;
+
+		/**
+		 * Constructor that creates a new instance and initializes it with a
+		 * plot as data provider.
+		 * @param plot The associated plot.
+		 */
+		public BarRenderer(BarPlot plot) {
+			this.plot = plot;
+			setValueLocation(Location.NORTH);
+			borderStroke = null;
+			borderColor = Color.BLACK;
+		}
+
+		/**
+		 * Returns the stroke used to paint the outline of the point shape.
+		 * @return Stroke used to paint the outline of the point shape.
+		 */
+		public Stroke getBorderStroke() {
+			return borderStroke;
+		}
+
+		/**
+		 * Sets the stroke used to paint the outline of the point shape.
+		 * @param stroke Stroke used to paint the outline of the point shape.
+		 */
+		public void setBorderStroke(Stroke stroke) {
+			this.borderStroke = stroke;
+		}
+
+		/**
+		 * Returns the paint which is used to fill the point shape.
+		 * @return Paint which is used to fill the point shape.
+		 */
+		public Paint getBorderColor() {
+			return borderColor;
+		}
+
+		/**
+		 * Sets the paint which will be used to fill the point shape.
+		 * @param color Paint which will be used to fill the point shape.
+		 */
+		public void setBorderColor(Paint color) {
+			this.borderColor = color;
+		}
+
+		@Override
+		public Drawable getPoint(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+				/** Version id for serialization. */
+				private static final long serialVersionUID = -3145112034673683520L;
+
+				public void draw(DrawingContext context) {
+					BarRenderer renderer = BarRenderer.this;
+
+					Rectangle2D paintBoundaries = null;
+					Graphics2D graphics = context.getGraphics();
+
+					ColorMapper colors = renderer.getColor();
+					Paint paint = colors.get(data.index);
+
+					if (plot.isPaintAllBars()) {
+						AffineTransform txOld = graphics.getTransform();
+						Rectangle2D shapeBounds = shape.getBounds2D();
+						paintBoundaries = new Rectangle2D.Double();//plot.getPlotArea().getBounds();
+						paintBoundaries = new Rectangle2D.Double(
+							shapeBounds.getX(), paintBoundaries.getY() - txOld.getTranslateY(),
+							shapeBounds.getWidth(), paintBoundaries.getHeight()
+						);
+					}
+
+					GraphicsUtils.fillPaintedShape(
+						graphics, shape, paint, paintBoundaries);
+
+					Stroke stroke = renderer.getBorderStroke();
+					Paint strokePaint = renderer.getBorderColor();
+					if (stroke != null && strokePaint != null) {
+						GraphicsUtils.drawPaintedShape(
+							graphics, shape, strokePaint, null, stroke);
+					}
+				}
+			};
+		}
+
+		/**
+		 * Returns a {@code Shape} instance that can be used for further
+		 * calculations.
+		 * @param data Information on axes, renderers, and values.
+		 * @return Outline that describes the point's shape.
+		 */
+		@Override
+		public Shape getPointShape(PointData data) {
+			int colX = 0;
+			int colY = 1;
+
+			Axis axisX = data.axes.get(0);
+			Axis axisY = data.axes.get(1);
+			AxisRenderer axisXRenderer = data.axisRenderers.get(0);
+			AxisRenderer axisYRenderer = data.axisRenderers.get(1);
+			Row row = data.row;
+
+			if (!row.isColumnNumeric(colX) || !row.isColumnNumeric(colY)) {
+				return null;
+			}
+
+			double valueX = ((Number) row.get(colX)).doubleValue();
+			double valueY = ((Number) row.get(colY)).doubleValue();
+			double axisYOrigin = 0.0;
+
+			double barWidthRel = plot.getBarWidth();
+			barWidthRel = Math.max(barWidthRel, 0.0);
+			double barAlign = 0.5;
+
+			double barXMin = axisXRenderer
+				.getPosition(axisX, valueX - barWidthRel*barAlign, true, false)
+				.get(PointND.X);
+			double barXMax = axisXRenderer
+				.getPosition(axisX, valueX + barWidthRel*barAlign, true, false)
+				.get(PointND.X);
+
+			double barYVal = axisYRenderer.getPosition(
+					axisY, valueY, true, false).get(PointND.Y);
+			double barYOrigin = axisYRenderer.getPosition(
+					axisY, axisYOrigin, true, false).get(PointND.Y);
+			double barYMin = Math.min(barYVal, barYOrigin);
+			double barYMax = Math.max(barYVal, barYOrigin);
+
+			double barWidth = Math.abs(barXMax - barXMin);
+			double barHeight = Math.abs(barYMax - barYMin);
+
+			// position of the bar's left edge in screen coordinates
+			double barX = axisXRenderer.getPosition(
+				axisX, valueX, true, false).get(PointND.X);
+			// position of the bar's upper edge in screen coordinates
+			// (the origin of the screen y axis is at the top)
+			boolean barAboveAxis = barYMax == barYOrigin;
+			double barY = barAboveAxis ? 0.0 : -barHeight;
+
+			double barHeightMin = plot.getBarHeightMin();
+			if (MathUtils.isCalculatable(barHeightMin) && barHeightMin > 0.0 &&
+					barHeight < barHeightMin) {
+				if (barAboveAxis) {
+					barY += -barHeightMin + barHeight;
+				}
+				barHeight = barHeightMin;
+			}
+
+			return getBarShape(
+				barXMin - barX, barY, barWidth, barHeight);
+		}
+
+		/**
+		 * Returns the shape for a bar. The default shape is defined in the
+		 * settings, but more complex shapes may be implemented by overriding
+		 * this method.
+		 * @param x Distance from the left in view units (e.g. pixels).
+		 * @param y Distance from the top in view units (e.g. pixels).
+		 * @param width Width of the shape in view units (e.g. pixels).
+		 * @param height Height of the shape in view units (e.g. pixels).
+		 * @return A geometric shape for displaying a bar in bar plot.
+		 */
+		protected Shape getBarShape(double x, double y, double width, double height) {
+			Shape shape = getShape();
+			Rectangle2D shapeBounds = shape.getBounds2D();
+
+			AffineTransform tx = new AffineTransform();
+			tx.translate(x, y);
+			tx.scale(width/shapeBounds.getWidth(), height/shapeBounds.getHeight());
+			tx.translate(-shapeBounds.getMinX(), -shapeBounds.getMinY());
+
+			return tx.createTransformedShape(shape);
+		}
+
+		/**
+		 * Returns a graphical representation of the value label to be drawn for
+		 * the specified data value.
+		 * @param data Information on axes, renderers, and values.
+		 * @param shape Outline that describes the bounds for the value label.
+		 * @return Component that can be used to draw the value label.
+		 */
+		@Override
+		public Drawable getValue(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+				/** Version id for serialization. */
+				private static final long serialVersionUID1 = -1133369168849171793L;
+
+				public void draw(DrawingContext context) {
+					PointRenderer renderer = BarRenderer.this;
+					Row row = data.row;
+
+					if (renderer.isValueVisible()) {
+						int colValue = renderer.getValueColumn();
+						drawValueLabel(context, shape, row, data.index, colValue);
+					}
+				}
+			};
+		}
+	}
+
+	/**
+	 * A legend implementation for bar plots that displays all values of the
+	 * data source as items.
+	 */
+	public static class BarPlotLegend extends ValueLegend {
+		/** Version id for serialization. */
+		private static final long serialVersionUID = 4752278896167602641L;
+
+		/** Plot that contains settings and renderers. */
+		private final BarPlot plot;
+
+		/**
+		 * Constructor that initializes the instance with a plot acting as a
+		 * provider for settings and renderers.
+		 * @param plot Plot.
+		 */
+		public BarPlotLegend(BarPlot plot) {
+			this.plot = plot;
+		}
+
+		@Override
+		protected Drawable getSymbol(final Row row) {
+			List<PointRenderer> pointRenderers = plot.getPointRenderers(row.getSource());
+			BarRenderer barRenderer = (BarRenderer) pointRenderers.get(0);
+			return new LegendSymbol(row, barRenderer,
+					plot.getFont(), plot.getLegend().getSymbolSize());
+		}
+	}
+
+	private static class LegendSymbol extends AbstractLegend.AbstractSymbol {
+		private final Row row;
+		private final BarRenderer barRenderer;
+
+		public LegendSymbol(Row row, BarRenderer barRenderer, Font font, Dimension2D symbolSize) {
+			super(font, symbolSize);
+			this.row = row;
+			this.barRenderer = barRenderer;
+		}
+
+		@Override
+		public void draw(DrawingContext context) {
+			double width = getPreferredSize().getWidth();
+			double height = getPreferredSize().getHeight();
+			Shape shape = barRenderer.getBarShape(0.0, 0.0, width, height);
+
+			Graphics2D graphics = context.getGraphics();
+			AffineTransform txOrig = graphics.getTransform();
+			graphics.translate(getX(), getY());
+			GraphicsUtils.fillPaintedShape(
+					context.getGraphics(), shape, barRenderer.getColor().get(0), null);
+			GraphicsUtils.drawPaintedShape(
+					context.getGraphics(), shape, barRenderer.getBorderColor(), null, barRenderer.getBorderStroke());
+			graphics.setTransform(txOrig);
+		}
+	}
+
+	/**
+	 * Creates a new instance and initializes it with the specified
+	 * data sources.
+	 * @param data Data to be displayed.
+	 */
+	public BarPlot(DataSource... data) {
+		super(data);
+
+		((XYPlotArea2D) getPlotArea()).setMajorGridX(false);
+		barWidth = 1.0;
+		barHeightMin = 0.0;
+		paintAllBars = false;
+
+		Legend legend = new BarPlotLegend(this);
+		setLegend(legend);
+
+		autoscaleAxes();
+	}
+
+	@Override
+	public void autoscaleAxis(String axisName) {
+		if (!AXIS_X.equals(axisName) && !AXIS_Y.equals(axisName)) {
+			super.autoscaleAxis(axisName);
+		}
+		Axis axis = getAxis(axisName);
+		if (axis == null || !axis.isAutoscaled()) {
+			return;
+		}
+
+		List<DataSource> sources = getData();
+		if (sources.isEmpty()) {
+			return;
+		}
+
+		int rowCount = 0;
+		for (DataSource data : sources) {
+			rowCount = Math.max(rowCount, data.getRowCount());
+		}
+		if (rowCount == 0) {
+			return;
+		}
+
+		double min = getAxisMin(axisName);
+		double max = getAxisMax(axisName);
+		double spacing = 0.0;
+		if (AXIS_X.equals(axisName)) {
+			// Add margin
+			double barWidth = getBarWidth();
+			double margin = barWidth*(max - min)/rowCount;
+			spacing = margin/2.0;
+		} else {
+			// Make sure 0 is always visible for y axis
+			min = Math.min(min, 0.0);
+			max = Math.max(max, 0.0);
+		}
+		axis.setRange(min - spacing, max + spacing);
+	}
+
+	@Override
+	public void add(int index, DataSource source, boolean visible) {
+		super.add(index, source, visible);
+
+		// Assign default renderers
+		PointRenderer pointRendererDefault = new BarRenderer(this);
+		LineRenderer lineRendererDefault = null;
+		AreaRenderer areaRendererDefault = null;
+		// FIXME: Overwrites possible present point and line renderers
+		setPointRenderers(source, pointRendererDefault);
+		setLineRenderers(source, lineRendererDefault);
+		setAreaRenderers(source, areaRendererDefault);
+	}
+
+	/**
+	 * Returns the width of the bars in axis coordinates.
+	 * @return Width of the bars in axis coordinates.
+	 */
+	public double getBarWidth() {
+		return barWidth;
+	}
+
+	/**
+	 * Sets the width of the bars in axis coordinates.
+	 * @param barWidth Width of the bars in axis coordinates.
+	 */
+	public void setBarWidth(double barWidth) {
+		this.barWidth = barWidth;
+	}
+
+	/**
+	 * Returns the minimum height of the bars in view units
+	 * (e.g. pixels on screen).
+	 * @return Minimum height of the bars in view units.
+	 */
+	public double getBarHeightMin() {
+		return barHeightMin;
+	}
+
+	/**
+	 * Sets the minimum height of the bars in view units
+	 * (e.g. pixels on screen).
+	 * @param barHeightMin Minimum height of the bars in view units.
+	 */
+	public void setBarHeightMin(double barHeightMin) {
+		this.barHeightMin = barHeightMin;
+	}
+
+	/**
+	 * Returns whether all bars are filled as a whole, or if each bar is filled
+	 * independently.
+	 * @return {@code true} if all bars are filled as a whole, or
+	 * 		   {@code false} if each bar is filled independently.
+	 */
+	public boolean isPaintAllBars() {
+		return paintAllBars;
+	}
+
+	/**
+	 * Sets whether all bars will be filled as a whole, or if each bar will be
+	 * filled independently.
+	 * @param paintAllBars {@code true} to fill all bars as a whole, or
+	 * 		   {@code false} to fill each bar independently.
+	 */
+	public void setPaintAllBars(boolean paintAllBars) {
+		this.paintAllBars = paintAllBars;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/BoxPlot.java

@@ -0,0 +1,760 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.BasicStroke;
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Line2D;
+import java.awt.geom.Rectangle2D;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.data.Column;
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.DataTable;
+import org.xbib.graphics.graph.gral.data.Row;
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.plots.colors.ColorMapper;
+import org.xbib.graphics.graph.gral.plots.colors.ContinuousColorMapper;
+import org.xbib.graphics.graph.gral.plots.colors.SingleColor;
+import org.xbib.graphics.graph.gral.plots.legends.AbstractLegend;
+import org.xbib.graphics.graph.gral.plots.legends.ValueLegend;
+import org.xbib.graphics.graph.gral.plots.points.AbstractPointRenderer;
+import org.xbib.graphics.graph.gral.plots.points.PointData;
+import org.xbib.graphics.graph.gral.plots.points.PointRenderer;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * <p>Class that displays data as a box-and-whisker plot showing summaries of
+ * important statistical values. The data source must provide six columns to
+ * the {@code BoxPlot}:</p>
+ * <ul>
+ *   <li>Box position (for multiple boxes)</li>
+ *   <li>Position of the center bar (e.g. median)</li>
+ *   <li>Length of the lower whisker and position of the bottom bar
+ *   (e.g. minimum)</li>
+ *   <li>Position of the bottom edge of the box (e.g. first quartile)</li>
+ *   <li>Position of the top edge of the box (e.g. third quartile)</li>
+ *   <li>Length of the upper whisker and position of the top bar
+ *   (e.g. maximum)</li>
+ * </ul>
+ * <p>The utility method {@link #createBoxData(DataSource)} can be used to
+ * obtain common statistics for these properties from the each column of an
+ * existing data source.</p>
+ *
+ * <p>To create a new {@code BoxPlot} simply create a new instance using
+ * a data source. Example:</p>
+ * <pre>
+ * DataTable data = new DataTable(Double.class, Double.class);
+ * data.add(10.98, -12.34);
+ * data.add( 7.65,  45.67);
+ * data.add(43.21,  89.01);
+ * DataSource boxData = BoxPlot.createBoxData(data);
+ * BoxPlot plot = new BoxPlot(boxData);
+ * </pre>
+ */
+public class BoxPlot extends XYPlot {
+	/** Version id for serialization. */
+	private static final long serialVersionUID = -3069831535208696337L;
+
+	/**
+	 * Class that renders a box and its whiskers in a box-and-whisker plot.
+	 */
+	public static class BoxWhiskerRenderer extends AbstractPointRenderer {
+		/** Version id for serialization. */
+		private static final long serialVersionUID = 2944482729753981341L;
+
+		/** Index of the column for the horizontal position of a box. */
+		private int positionColumn;
+		/** Index of the column for the vertical center bar. */
+		private int centerBarColumn;
+		/** Index of the column for the lower vertical bar. */
+		private int bottomBarColumn;
+		/** Index of the column for the lower end of the box. */
+		private int boxBottomColumn;
+		/** Index of the column for the upper end of the box. */
+		private int boxTopColumn;
+		/** Index of the column for the upper vertical bar. */
+		private int topBarColumn;
+
+		/** Relative width of each box. 1.0 means boxes touch each other. */
+		private double boxWidth;
+		/** Color mapping to fill the background of the boxes. */
+		private ColorMapper boxBackground;
+		/** Paint to fill the border of the boxes. */
+		private Paint boxBorderColor;
+		/** Stroke to draw the border of the boxes. */
+		private transient Stroke boxBorderStroke;
+
+		/** Paint to fill the border of the whiskers. */
+		private Paint whiskerColor;
+		/** Stroke to draw the border of the whiskers. */
+		private transient Stroke whiskerStroke;
+
+		/** Relative width of the vertical bars. */
+		private double barWidth;
+		/** Paint to fill the center bar. */
+		private Paint centerBarColor;
+		/** Stroke to draw the center bar. */
+		private transient Stroke centerBarStroke;
+
+		/**
+		 * Constructor that creates a new instance and initializes it with a
+		 * plot as data provider.
+		 */
+		public BoxWhiskerRenderer() {
+			positionColumn = 0;
+			centerBarColumn = 1;
+			bottomBarColumn = 2;
+			boxBottomColumn = 3;
+			boxTopColumn = 4;
+			topBarColumn = 5;
+			boxWidth = 0.75;
+			boxBackground = new SingleColor(Color.WHITE);
+			boxBorderColor = Color.BLACK;
+			boxBorderStroke = new BasicStroke(1f);
+			whiskerColor = Color.BLACK;
+			whiskerStroke = new BasicStroke(1f);
+			barWidth = 0.75;
+			centerBarColor = Color.BLACK;
+			centerBarStroke = new BasicStroke(
+				2f, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER);
+		}
+
+		/**
+		 * Returns the index of the column which is used for the horizontal
+		 * position of a box.
+		 * @return Index of the column that is used for the horizontal position
+		 * of a box.
+		 */
+		public int getPositionColumn() {
+			return positionColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the horizontal
+		 * position of a box.
+		 * @param columnIndex Index of the column that is used for the
+		 * horizontal position of a box.
+		 */
+		public void setPositionColumn(int columnIndex) {
+			this.positionColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the center bar.
+		 * @return Index of the column which is used for the center bar.
+		 */
+		public int getCenterBarColumn() {
+			return centerBarColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the center bar.
+		 * @param columnIndex Index of the column which will be used for
+		 * the center bar.
+		 */
+		public void setCenterBarColumn(int columnIndex) {
+			this.centerBarColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the bottom bar.
+		 * @return Index of the column which is used for the bottom bar.
+		 */
+		public int getBottomBarColumn() {
+			return bottomBarColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the bottom bar.
+		 * @param columnIndex Index of the column which will be used for
+		 * the bottom bar.
+		 */
+		public void setBottomBarColumn(int columnIndex) {
+			this.bottomBarColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the bottom edge of
+		 * the box.
+		 * @return Index of the column which is used for the bottom edge of the
+		 * box.
+		 */
+		public int getBoxBottomColumn() {
+			return boxBottomColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the bottom edge
+		 * of the box.
+		 * @param columnIndex Index of the column which will be used for
+		 * the bottom edge of the box.
+		 */
+		public void setColumnBoxBottom(int columnIndex) {
+			this.boxBottomColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the top edge of
+		 * the box.
+		 * @return Index of the column which is used for the top edge of the
+		 * box.
+		 */
+		public int getBoxTopColumn() {
+			return boxTopColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the top edge of
+		 * the box.
+		 * @param columnIndex Index of the column which will be used for the
+		 * top edge of the box.
+		 */
+		public void setBoxTopColumn(int columnIndex) {
+			this.boxTopColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the top bar.
+		 * @return Index of the column which is used for the top bar.
+		 */
+		public int getTopBarColumn() {
+			return topBarColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the top bar.
+		 * @param columnIndex Index of the column which will be used for the
+		 * top bar.
+		 */
+		public void setTopBarColumn(int columnIndex) {
+			this.topBarColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the relative width of the box.
+		 * @return Relative width of the box.
+		 */
+		public double getBoxWidth() {
+			return boxWidth;
+		}
+
+		/**
+		 * Sets the relative width of the box.
+		 * @param boxWidth Relative width of the box.
+		 */
+		public void setBoxWidth(double boxWidth) {
+			this.boxWidth = boxWidth;
+		}
+
+		/**
+		 * Returns the mapping which is used to fill the background of a box.
+		 * @return {@code ColorMapper} instance which is used to fill the
+		 * background of a box.
+		 */
+		public ColorMapper getBoxBackground() {
+			return boxBackground;
+		}
+
+		/**
+		 * Sets the mapping which will be used to fill the background of a box.
+		 * @param color {@code ColorMapper} instance which will be used to fill
+		 * the background of a box.
+		 */
+		public void setBoxBackground(ColorMapper color) {
+			this.boxBackground = color;
+		}
+
+		/**
+		 * Sets the paint which will be used to fill the background of a box.
+		 * @param color {@code Paint} instance which will be used to fill the
+		 * background of a box.
+		 */
+		public void setBoxBackground(Paint color) {
+			setBoxBackground(new SingleColor(color));
+		}
+
+		/**
+		 * Returns the paint which is used to fill the border of a box and the
+		 * lines of bars.
+		 * @return Paint which is used to fill the border of a box and the
+		 * lines of bars.
+		 */
+		public Paint getBoxBorderColor() {
+			return boxBorderColor;
+		}
+
+		/**
+		 * Sets the paint which will be used to fill the border of a box and
+		 * the lines of bars.
+		 * @param color Paint which will be used to fill the border of a box
+		 * and the lines of bars.
+		 */
+		public void setBoxBorderColor(Paint color) {
+			this.boxBorderColor = color;
+		}
+
+		/**
+		 * Returns the stroke which is used to paint the border of a box and
+		 * the lines of the bars.
+		 * @return {@code Stroke} instance which is used to paint the border of
+		 * a box and the lines of the bars.
+		 */
+		public Stroke getBoxBorderStroke() {
+			return boxBorderStroke;
+		}
+
+		/**
+		 * Sets the stroke which will be used to paint the border of a box and
+		 * the lines of the bars.
+		 * @param stroke {@code Stroke} instance which will be used to paint
+		 * the border of a box and the lines of the bars.
+		 */
+		public void setBoxBorderStroke(Stroke stroke) {
+			this.boxBorderStroke = stroke;
+		}
+
+		/**
+		 * Returns the paint which is used to fill the lines of the whiskers.
+		 * @return Paint which is used to fill the lines of the whiskers.
+		 */
+		public Paint getWhiskerColor() {
+			return whiskerColor;
+		}
+
+		/**
+		 * Sets the paint which will be used to fill the lines of the whiskers.
+		 * @param color Paint which will be used to fill the lines of the
+		 * whiskers.
+		 */
+		public void setWhiskerColor(Paint color) {
+			this.whiskerColor = color;
+		}
+
+		/**
+		 * Returns the stroke which is used to paint the lines of the whiskers.
+		 * @return {@code Stroke} instance which is used to paint the lines of
+		 * the whiskers.
+		 */
+		public Stroke getWhiskerStroke() {
+			return whiskerStroke;
+		}
+
+		/**
+		 * Sets the stroke which will be used to paint the lines of the
+		 * whiskers.
+		 * @param stroke {@code Stroke} instance which will be used to paint
+		 * the lines of the whiskers.
+		 */
+		public void setWhiskerStroke(Stroke stroke) {
+			this.whiskerStroke = stroke;
+		}
+
+		/**
+		 * Returns the relative width of the bottom and top bars.
+		 * @return Relative width of the bottom and top bars.
+		 */
+		public double getBarWidth() {
+			return barWidth;
+		}
+
+		/**
+		 * Sets the relative width of the bottom and top bars.
+		 * @param width Relative width of the bottom and top bars.
+		 */
+		public void setBarWidth(double width) {
+			this.barWidth = width;
+		}
+
+		/**
+		 * Returns the paint which is used to fill the lines of the center bar.
+		 * @return Paint which is used to fill the lines of the center bar.
+		 */
+		public Paint getCenterBarColor() {
+			return centerBarColor;
+		}
+
+		/**
+		 * Sets the paint which will be used to fill the lines of the center
+		 * bar.
+		 * @param color Paint which will be used to fill the lines of the
+		 * center bar.
+		 */
+		public void setCenterBarColor(Paint color) {
+			this.centerBarColor = color;
+		}
+
+		/**
+		 * Returns the stroke which is used to paint the lines of the center
+		 * bar.
+		 * @return {@code Stroke} instance which is used to paint the lines of
+		 * the center bar.
+		 */
+		public Stroke getCenterBarStroke() {
+			return centerBarStroke;
+		}
+
+		/**
+		 * Sets the stroke which will be used to paint the lines of the
+		 * center bar.
+		 * @param stroke {@code Stroke} instance which will be used to paint
+		 * the lines of the center bar.
+		 */
+		public void setCenterBarStroke(Stroke stroke) {
+			this.centerBarStroke = stroke;
+		}
+
+		@Override
+		public Drawable getPoint(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+
+				public void draw(DrawingContext context) {
+					Axis axisX = data.axes.get(0);
+					Axis axisY = data.axes.get(1);
+					AxisRenderer axisXRenderer = data.axisRenderers.get(0);
+					AxisRenderer axisYRenderer = data.axisRenderers.get(1);
+					Row row = data.row;
+
+					// Get the values from data columns
+					BoxWhiskerRenderer renderer =  BoxWhiskerRenderer.this;
+					int colPos = renderer.getPositionColumn();
+					int colBarCenter = renderer.getCenterBarColumn();
+					int colBarBottom = renderer.getBottomBarColumn();
+					int colBoxBottom = renderer.getBoxBottomColumn();
+					int colBoxTop = renderer.getBoxTopColumn();
+					int colBarTop = renderer.getTopBarColumn();
+
+					if (!row.isColumnNumeric(colPos) ||
+							!row.isColumnNumeric(colBarCenter) ||
+							!row.isColumnNumeric(colBarBottom) ||
+							!row.isColumnNumeric(colBoxBottom) ||
+							!row.isColumnNumeric(colBoxTop) ||
+							!row.isColumnNumeric(colBarTop)) {
+						return;
+					}
+
+					double valueX = ((Number) row.get(colPos)).doubleValue();
+					double valueYBarBottom = ((Number) row.get(colBarBottom)).doubleValue();
+					double valueYBoxBottom = ((Number) row.get(colBoxBottom)).doubleValue();
+					double valueYBarCenter = ((Number) row.get(colBarCenter)).doubleValue();
+					double valueYBoxTop = ((Number) row.get(colBoxTop)).doubleValue();
+					double valueYBarTop = ((Number) row.get(colBarTop)).doubleValue();
+
+					// Calculate positions in screen units
+					double boxWidthRel = getBoxWidth();
+					double boxAlign = 0.5;
+					// Box X
+					double boxXMin = axisXRenderer
+						.getPosition(axisX, valueX - boxWidthRel*boxAlign, true, false)
+						.get(PointND.X);
+					double boxX = axisXRenderer.getPosition(
+						axisX, valueX, true, false).get(PointND.X);
+					double boxXMax = axisXRenderer
+						.getPosition(axisX, valueX + boxWidthRel*boxAlign, true, false)
+						.get(PointND.X);
+					// Box Y
+					double barYbottom = axisYRenderer.getPosition(
+						axisY, valueYBarBottom, true, false).get(PointND.Y);
+					double boxYBottom = axisYRenderer.getPosition(
+						axisY, valueYBoxBottom, true, false).get(PointND.Y);
+					double barYCenter = axisYRenderer.getPosition(
+						axisY, valueYBarCenter, true, false).get(PointND.Y);
+					double boxYTop = axisYRenderer.getPosition(
+						axisY, valueYBoxTop, true, false).get(PointND.Y);
+					double barYTop = axisYRenderer.getPosition(
+						axisY, valueYBarTop, true, false).get(PointND.Y);
+					double boxWidth = Math.abs(boxXMax - boxXMin);
+					// Bars
+					double barWidthRel = getBarWidth();
+					double barXMin = boxXMin + (1.0 - barWidthRel)*boxWidth/2.0;
+					double barXMax = boxXMax - (1.0 - barWidthRel)*boxWidth/2.0;
+
+					// Create shapes
+					// The origin of all shapes is (boxX, boxY)
+					Rectangle2D boxBounds = new Rectangle2D.Double(
+						boxXMin - boxX, boxYTop - barYCenter,
+						boxWidth, Math.abs(boxYTop - boxYBottom));
+					Rectangle2D shapeBounds = shape.getBounds2D();
+					AffineTransform tx = new AffineTransform();
+					tx.translate(boxBounds.getX(), boxBounds.getY());
+					tx.scale(boxBounds.getWidth()/shapeBounds.getWidth(),
+						boxBounds.getHeight()/shapeBounds.getHeight());
+					tx.translate(-shapeBounds.getMinX(), -shapeBounds.getMinY());
+					Shape box = tx.createTransformedShape(shape);
+
+					Line2D whiskerMax = new Line2D.Double(
+						0.0, boxYTop - barYCenter,
+						0.0, barYTop - barYCenter
+					);
+					Line2D whiskerMin = new Line2D.Double(
+						0.0, boxYBottom - barYCenter,
+						0.0, barYbottom - barYCenter
+					);
+					Line2D barMax = new Line2D.Double(
+						barXMin - boxX, barYTop - barYCenter,
+						barXMax - boxX, barYTop - barYCenter
+					);
+					Line2D barMin = new Line2D.Double(
+						barXMin - boxX, barYbottom - barYCenter,
+						barXMax - boxX, barYbottom - barYCenter
+					);
+					Line2D barCenter = new Line2D.Double(
+						boxXMin - boxX, 0.0,
+						boxXMax - boxX, 0.0
+					);
+
+					// Paint shapes
+					Graphics2D graphics = context.getGraphics();
+					ColorMapper paintBoxMapper = getBoxBackground();
+					Paint paintBox;
+					if (paintBoxMapper instanceof ContinuousColorMapper) {
+						paintBox = ((ContinuousColorMapper) paintBoxMapper)
+							.get(valueX);
+					} else {
+						int index = data.index;
+						paintBox = paintBoxMapper.get(index);
+					}
+					Paint paintStrokeBox = getBoxBorderColor();
+					Stroke strokeBox = getBoxBorderStroke();
+					Paint paintWhisker = getWhiskerColor();
+					Stroke strokeWhisker = getWhiskerStroke();
+					Paint paintBarCenter = getCenterBarColor();
+					Stroke strokeBarCenter = getCenterBarStroke();
+					// Fill box
+					GraphicsUtils.fillPaintedShape(
+						graphics, box, paintBox, box.getBounds2D());
+					// Save current graphics state
+					Paint paintOld = graphics.getPaint();
+					Stroke strokeOld = graphics.getStroke();
+					// Draw whiskers
+					graphics.setPaint(paintWhisker);
+					graphics.setStroke(strokeWhisker);
+					graphics.draw(whiskerMax);
+					graphics.draw(whiskerMin);
+					// Draw box and bars
+					graphics.setPaint(paintStrokeBox);
+					graphics.setStroke(strokeBox);
+					graphics.draw(box);
+					graphics.draw(barMax);
+					graphics.draw(barMin);
+					graphics.setPaint(paintBarCenter);
+					graphics.setStroke(strokeBarCenter);
+					graphics.draw(barCenter);
+					// Restore previous graphics state
+					graphics.setStroke(strokeOld);
+					graphics.setPaint(paintOld);
+				}
+			};
+		}
+
+		/**
+		 * Returns a {@code Shape} instance that can be used for further
+		 * calculations.
+		 * @param data Information on axes, renderers, and values.
+		 * @return Outline that describes the point's shape.
+		 */
+		public Shape getPointShape(PointData data) {
+			return getShape();
+		}
+
+		/**
+		 * Returns a graphical representation of the value label to be drawn for
+		 * the specified data value.
+		 * @param data Information on axes, renderers, and values.
+		 * @param shape Outline that describes the bounds for the value label.
+		 * @return Component that can be used to draw the value label.
+		 */
+		public Drawable getValue(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+				/** Version id for serialization. */
+				private static final long serialVersionUID1 = 6788431763837737592L;
+
+				public void draw(DrawingContext context) {
+					// TODO Implement rendering of value label
+				}
+			};
+		}
+	}
+
+	/**
+	 * A legend implementation for box-and-whisker plots that displays all
+	 * values of the data source as items.
+	 */
+	public static class BoxPlotLegend extends ValueLegend {
+		/** Version id for serialization. */
+		private static final long serialVersionUID = 1517792984459627757L;
+
+		/** Associated plot. */
+		private final BoxPlot plot;
+
+		/**
+		 * Initializes a new instance with the specified plot.
+		 * @param plot Associated plot.
+		 */
+		public BoxPlotLegend(BoxPlot plot) {
+			this.plot = plot;
+		}
+
+		@Override
+		protected Drawable getSymbol(final Row row) {
+			return new LegendSymbol(row, (BoxWhiskerRenderer) plot.getPointRenderers(row.getSource()).get(0),
+					plot.getFont(), plot.getLegend().getSymbolSize());
+		}
+	}
+
+	private static class LegendSymbol extends AbstractLegend.AbstractSymbol {
+		private final Row row;
+		private final BoxWhiskerRenderer boxWhiskerRenderer;
+
+		public LegendSymbol(Row row, BoxWhiskerRenderer boxWhiskerRenderer, Font font, Dimension2D symbolSize) {
+			super(font, symbolSize);
+			this.row = row;
+			this.boxWhiskerRenderer = boxWhiskerRenderer;
+		}
+
+		@Override
+		public void draw(DrawingContext context) {
+			Shape shape = new Rectangle2D.Double(0.0, 0.0, getBounds().getWidth(), getBounds().getHeight());
+
+			Graphics2D graphics = context.getGraphics();
+			AffineTransform txOrig = graphics.getTransform();
+			graphics.translate(getX(), getY());
+			GraphicsUtils.fillPaintedShape(context.getGraphics(), shape,
+					boxWhiskerRenderer.getBoxBackground().get(row.getIndex()), null);
+			GraphicsUtils.drawPaintedShape(context.getGraphics(), shape, boxWhiskerRenderer.getBoxBorderColor(),
+					null, boxWhiskerRenderer.getBoxBorderStroke());
+			graphics.setTransform(txOrig);
+		}
+	}
+
+	/**
+	 * Initializes a new box-and-whisker plot with the specified data source.
+	 * @param data Data to be displayed.
+	 */
+	public BoxPlot(DataSource data) {
+		setLegend(new BoxPlotLegend(this));
+
+		((XYPlotArea2D) getPlotArea()).setMajorGridX(false);
+		getAxisRenderer(AXIS_X).setTickSpacing(1.0);
+		getAxisRenderer(AXIS_X).setMinorTicksVisible(false);
+		getAxisRenderer(AXIS_X).setIntersection(-Double.MAX_VALUE);
+		getAxisRenderer(AXIS_Y).setIntersection(-Double.MAX_VALUE);
+
+		add(data);
+		autoscaleAxes();
+	}
+
+	/**
+	 * Extracts statistics from the columns of an data source that are commonly
+	 * used for box-and-whisker plots. The result is a new data source
+	 * containing <i>column index</i>, <i>median</i>, <i>mininum</i>, <i>first
+	 * quartile</i>, <i>third quartile</i>, and <i>maximum</i> for each column.
+	 * @param data Original data source
+	 * @return New data source with (columnIndex, median, min, quartile1,
+	 *         quartile3, max)
+	 */
+	@SuppressWarnings("unchecked")
+	public static DataSource createBoxData(DataSource data) {
+		if (data == null) {
+			throw new NullPointerException(
+				"Cannot extract statistics from null data source.");
+		}
+
+		DataTable stats = new DataTable(Integer.class, Double.class,
+			Double.class, Double.class, Double.class, Double.class);
+
+		// Generate statistical values for each column
+		for (int c = 0; c < data.getColumnCount(); c++) {
+			Column<?> col = data.getColumn(c);
+			if (!col.isNumeric()) {
+				continue;
+			}
+			stats.add(
+				c + 1,
+				col.getStatistics(Statistics.MEDIAN),
+				col.getStatistics(Statistics.MIN),
+				col.getStatistics(Statistics.QUARTILE_1),
+				col.getStatistics(Statistics.QUARTILE_3),
+				col.getStatistics(Statistics.MAX)
+			);
+		}
+		return stats;
+	}
+
+	@Override
+	public void add(int index, DataSource source, boolean visible) {
+		if (getData().size() > 0) {
+			throw new IllegalArgumentException(
+				"This plot type only supports a single data source."); //$NON-NLS-1$
+		}
+		// By the looks of it, some objects depend on a BoxWhiskerRenderer being present when super.add is called
+		// However, super.add overwrites renderers, so we have to create the BoxWhiskerRenderer twice.
+		BoxWhiskerRenderer renderer = new BoxWhiskerRenderer();
+		setPointRenderers(source, renderer);
+		super.add(index, source, visible);
+		// FIXME: Overwrites possible present point and line renderers
+		setLineRenderers(source, null);
+		setPointRenderers(source, renderer);
+	}
+
+	@Override
+	public void autoscaleAxis(String axisName) {
+		if (!AXIS_X.equals(axisName) && !AXIS_Y.equals(axisName)) {
+			super.autoscaleAxis(axisName);
+		}
+		Axis axis = getAxis(axisName);
+		if (axis == null || !axis.isAutoscaled()) {
+			return;
+		}
+
+		List<DataSource> sources = getData();
+		if (sources.isEmpty()) {
+			return;
+		}
+
+		boolean isXAxis = AXIS_X.equals(axisName);
+
+		double min = Double.MAX_VALUE;
+		double max = Double.MIN_VALUE;
+		for (DataSource data : sources) {
+			BoxWhiskerRenderer pointRenderer = null;
+			for (PointRenderer p : getPointRenderers(data)) {
+				if (p instanceof BoxWhiskerRenderer) {
+					pointRenderer = (BoxWhiskerRenderer) p;
+					break;
+				}
+			}
+
+			if (pointRenderer == null) {
+				continue;
+			}
+
+			int minColumnIndex, maxColumnIndex;
+			if (isXAxis) {
+				minColumnIndex = pointRenderer.getPositionColumn();
+				maxColumnIndex = pointRenderer.getPositionColumn();
+			} else {
+				minColumnIndex = pointRenderer.getBottomBarColumn();
+				maxColumnIndex = pointRenderer.getTopBarColumn();
+			}
+
+			min = Math.min(min, data.getColumn(minColumnIndex)
+					.getStatistics(Statistics.MIN));
+			max = Math.max(max, data.getColumn(maxColumnIndex)
+					.getStatistics(Statistics.MAX));
+		}
+		double spacing = (isXAxis) ? 0.5 : 0.05*(max - min);
+		axis.setRange(min - spacing, max + spacing);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/DataPoint.java

@@ -0,0 +1,26 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import org.xbib.graphics.graph.gral.plots.points.PointData;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+
+/**
+ * Class for storing points of a plot.
+ */
+public class DataPoint {
+	/** Axes and data values that were used to create the data point. */
+	public final PointData data;
+	/** Position of the data point (n-dimensional). */
+	public final PointND<Double> position;
+
+	/**
+	 * Creates a new {@code DataPoint} object with the specified position,
+	 * {@code Drawable}, and shape.
+	 * @param data Data that this point was created from.
+	 * @param position Coordinates in view/screen units.
+	 */
+	public DataPoint(PointData data, PointND<Double> position) {
+		this.data = data;
+		this.position = position;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/Plot.java

@@ -0,0 +1,284 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.Font;
+import java.awt.Paint;
+import java.awt.Stroke;
+import java.util.Collection;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.graphics.Container;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Label;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.plots.legends.Legend;
+import org.xbib.graphics.graph.gral.graphics.Location;
+
+/**
+ * <p>Interface for classes that display data in a plot.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Adding axes to the plot</li>
+ *   <li>Adding a title to the plot</li>
+ *   <li>Adding a legend to the plot</li>
+ *   <li>Administration of settings</li>
+ * </ul>
+ */
+public interface Plot extends Drawable, Container {
+	/**
+	 * Returns the axis with the specified name.
+	 * @param name Name of the axis.
+	 * @return Axis.
+	 */
+	Axis getAxis(String name);
+
+	/**
+	 * Sets the axis with the specified name and the associated
+	 * {@code AxisRenderer}.
+	 * @param name Name of the axis.
+	 * @param axis Axis.
+	 */
+	void setAxis(String name, Axis axis);
+
+	/**
+	 * Removes the axis with the specified name.
+	 * @param name Name of the axis to be removed.
+	 */
+	void removeAxis(String name);
+
+	/**
+	 * Returns a collection of all names of the axes stored in this plot.
+	 * @return The names of all axes stored in this plot.
+	 */
+	Collection<String> getAxesNames();
+
+	/**
+	 * Tries to automatically set the ranges of the axes specified by the name
+	 * if it is set to auto-scale.
+	 * @param axisName Name of the axis that should be scaled.
+	 * @see Axis#setAutoscaled(boolean)
+	 */
+	void autoscaleAxis(String axisName);
+
+	/**
+	 * Returns the renderer for the axis with the specified name.
+	 * @param axisName Axis name.
+	 * @return Instance that renders the axis.
+	 */
+	AxisRenderer getAxisRenderer(String axisName);
+
+	/**
+	 * Sets the renderer for the axis with the specified name.
+	 * @param axisName Name of the axis to be rendered.
+	 * @param renderer Instance to render the axis.
+	 */
+	void setAxisRenderer(String axisName, AxisRenderer renderer);
+
+	/**
+	 * Returns the drawing area of this plot.
+	 * @return {@code PlotArea2D}.
+	 */
+	PlotArea getPlotArea();
+
+	/**
+	 * Returns the title component of this plot.
+	 * @return Label representing the title.
+	 */
+	Label getTitle();
+
+	/**
+	 * Returns the legend component.
+	 * @return Legend.
+	 */
+	Legend getLegend();
+
+	/**
+	 * Adds a new data series to the plot which is visible by default.
+	 * @param source Data series.
+	 */
+	void add(DataSource source);
+
+	/**
+	 * Adds a new data series to the plot.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be displayed,
+	 *        {@code false} otherwise.
+	 */
+	void add(DataSource source, boolean visible);
+
+	/**
+	 * Inserts the specified data series to the plot at a specified position.
+	 * @param index Position.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be displayed,
+	 *        {@code false} otherwise.
+	 */
+	void add(int index, DataSource source, boolean visible);
+
+	/**
+	 * Returns whether the plot contains the specified data series.
+	 * @param source Data series.
+	 * @return {@code true} if the specified element is stored in the
+	 *         plot, otherwise {@code false}
+	 */
+	boolean contains(DataSource source);
+
+	/**
+	 * Returns the data series at a specified index.
+	 * @param index Position of the data series.
+	 * @return Instance of the data series.
+	 */
+	DataSource get(int index);
+
+	/**
+	 * Deletes the specified data series from the plot.
+	 * @param source Data series.
+	 * @return {@code true} if the series existed,
+	 *         otherwise {@code false}.
+	 */
+	boolean remove(DataSource source);
+
+	/**
+	 * Removes all data series from this plot.
+	 */
+	void clear();
+
+	/**
+	 * Returns the mapping of data source columns to axis names. The elements
+	 * of returned array equal the column indexes, i.e. the first element (axis
+	 * name) matches the first column of {@code source}. If no mapping exists
+	 * {@code null} will be stored in the array.
+	 * @param source Data source.
+	 * @return Array containing axis names in the order of the columns,
+	 *         or {@code null} if no mapping exists for the column.
+	 */
+	String[] getMapping(DataSource source);
+
+	/**
+	 * Sets the mapping of data source columns to axis names. The column index
+	 * is taken from the order of the axis names, i.e. the first column of
+	 * {@code source} will be mapped to first element of {@code axisNames}.
+	 * Axis names with value {@code null} will be ignored.
+	 * @param source Data source.
+	 * @param axisNames Sequence of axis names in the order of the columns.
+	 */
+	void setMapping(DataSource source, String... axisNames);
+
+	/**
+	 * Returns a list of all data series stored in the plot.
+	 * @return List of all data series.
+	 */
+	List<DataSource> getData();
+
+	/**
+	 * Returns a list of all visible data series stored in the plot.
+	 * @return List of all visible data series.
+	 */
+	List<DataSource> getVisibleData();
+
+	/**
+	 * Returns whether the specified data series is drawn.
+	 * @param source Data series.
+	 * @return {@code true} if visible, {@code false} otherwise.
+	 */
+	boolean isVisible(DataSource source);
+
+	/**
+	 * Changes the visibility of the specified data series.
+	 * @param source Data series.
+	 * @param visible {@code true} if the series should be visible,
+	 *        {@code false} otherwise.
+	 */
+	void setVisible(DataSource source, boolean visible);
+
+	/**
+	 * Returns the paint which is used to fill the background of the plot.
+	 * @return Paint which is used to fill the background of the plot.
+	 */
+	Paint getBackground();
+
+	/**
+	 * Sets the paint which will be used to fill the background of the plot.
+	 * @param background Paint which will be used to fill the background of the
+	 * plot.
+	 */
+	void setBackground(Paint background);
+
+	/**
+	 * Returns the stroke which is used to paint the border of the plot.
+	 * @return Stroke which is used to paint the border of the plot.
+	 */
+	Stroke getBorderStroke();
+
+	/**
+	 * Sets the stroke which will be used to paint the border of the plot.
+	 * @param border Stroke which will be used to paint the border of the plot.
+	 */
+	void setBorderStroke(Stroke border);
+
+	/**
+	 * Returns the paint which is used to fill the border of the plot.
+	 * @return Paint which is used to fill the border of the plot.
+	 */
+	Paint getBorderColor();
+
+	/**
+	 * Sets the paint which will be used to fill the border of the plot.
+	 * @param color Paint which will be used to fill the border of the plot.
+	 */
+	void setBorderColor(Paint color);
+
+	/**
+	 * Returns the base font used by the plot.
+	 * @return Font used by the plot.
+	 */
+	Font getFont();
+
+	/**
+	 * Sets the base font that will be used by the plot.
+	 * @param font Font that will used by the plot.
+	 */
+	void setFont(Font font);
+
+	/**
+	 * Returns whether the legend is shown.
+	 * @return {@code true} if the legend is shown,
+	 *         {@code false} if the legend is hidden.
+	 */
+	boolean isLegendVisible();
+
+	/**
+	 * Sets whether the legend will be shown.
+	 * @param legendVisible {@code true} if the legend should be shown,
+	 *         {@code false} if the legend should be hidden.
+	 */
+	void setLegendVisible(boolean legendVisible);
+
+	/**
+	 * Returns the current positioning of the legend inside the plot.
+	 * @return Current positioning of the legend inside the plot.
+	 */
+	Location getLegendLocation();
+
+	/**
+	 * Sets the positioning of the legend inside the plot.
+	 * @param location Positioning of the legend inside the plot.
+	 */
+	void setLegendLocation(Location location);
+
+	/**
+	 * Returns the spacing between the plot area and the legend.
+	 * @return Spacing between the plot area and the legend relative to font
+	 * height.
+	 */
+	double getLegendDistance();
+
+	/**
+	 * Sets the spacing between the plot area and the legend.
+	 * The distance is defined in font height.
+	 * @param distance Spacing between the plot area and the legend relative to font
+	 * height.
+	 */
+	void setLegendDistance(double distance);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/PlotArea.java

@@ -0,0 +1,170 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.BasicStroke;
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Paint;
+import java.awt.Stroke;
+
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.graphics.Insets2D;
+
+/**
+ * Abstract class that represents a canvas on which plot data will be drawn.
+ * It serves as base for specialized implementations for different plot types.
+ * Derived classes have to implement how the actual drawing is done.
+ */
+public abstract class PlotArea extends AbstractDrawable {
+
+	/** Default font used for sub-components and the calculation of relative
+	sizes. */
+	private Font baseFont;
+	/** Paint to fill the background. */
+	private Paint background;
+	/** Stroke to draw the border.
+	Property will be serialized using a wrapper. */
+	private transient Stroke borderStroke;
+	/** Paint to fill the border. */
+	private Paint borderColor;
+	/** Offset to clip plot graphics in pixels, specified relative to the
+	outline of the plot area. */
+	private Insets2D clippingOffset;
+
+	/**
+	 * Initializes a new instance with default background color and border.
+	 */
+	public PlotArea() {
+		baseFont = null;
+		background = Color.WHITE;
+		borderStroke = new BasicStroke(1f);
+		borderColor = Color.BLACK;
+		clippingOffset = new Insets2D.Double(0.0);
+	}
+
+	/**
+	 * Draws the background of this legend with the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	protected void drawBackground(DrawingContext context) {
+		// FIXME duplicate code! See de.erichseifert.gral.Legend
+		Paint paint = getBackground();
+		if (paint != null) {
+			GraphicsUtils.fillPaintedShape(context.getGraphics(),
+					getBounds(), paint, null);
+		}
+	}
+
+	/**
+	 * Draws the border of this Legend with the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	protected void drawBorder(DrawingContext context) {
+		// FIXME duplicate code! See de.erichseifert.gral.Legend
+		Stroke stroke = getBorderStroke();
+		if (stroke != null) {
+			Paint borderColor = getBorderColor();
+			GraphicsUtils.drawPaintedShape(context.getGraphics(),
+					getBounds(), borderColor, null, stroke);
+		}
+	}
+
+	/**
+	 * Draws the data using the specified drawing context.
+	 * @param context Environment used for drawing.
+	 */
+	protected abstract void drawPlot(DrawingContext context);
+
+	/**
+	 * Returns the current font used as a default for sub-components ans for
+	 * calculation of relative sizes.
+	 * @return Current base font.
+	 */
+	public Font getBaseFont() {
+		return baseFont;
+	}
+
+	/**
+	 * Sets the new font that will be used as a default for sub-components and
+	 * for calculation of relative sizes. This method is only used internally
+	 * to propagate the base font and shouldn't be used manually.
+	 * @param baseFont New base font.
+	 */
+	public void setBaseFont(Font baseFont) {
+		this.baseFont = baseFont;
+	}
+
+	/**
+	 * Returns the paint which is used to draw the background of the plot area.
+	 * @return Paint which is used to fill the background.
+	 */
+	public Paint getBackground() {
+		return background;
+	}
+
+	/**
+	 * Sets the paint which will be used to fill the background of the plot
+	 * area.
+	 * @param background Paint which should be used to fill the background.
+	 */
+	public void setBackground(Paint background) {
+		this.background = background;
+	}
+
+	/**
+	 * Returns the stroke which is used to draw the border of the plot area.
+	 * @return Stroke which is used to draw the border.
+	 */
+	public Stroke getBorderStroke() {
+		return borderStroke;
+	}
+
+	/**
+	 * Sets the stroke which will be used to draw the border of the plot area.
+	 * @param stroke Stroke which should be used to draw the border.
+	 */
+	public void setBorderStroke(Stroke stroke) {
+		this.borderStroke = stroke;
+	}
+
+	/**
+	 * Returns the paint which is used to fill the border of the plot area.
+	 * @return Paint which is used to fill the border.
+	 */
+	public Paint getBorderColor() {
+		return borderColor;
+	}
+
+	/**
+	 * Sets the paint which will be used to fill the border of the plot area.
+	 * @param color Paint which should be used to fill the border.
+	 */
+	public void setBorderColor(Paint color) {
+		this.borderColor = color;
+	}
+
+	/**
+	 * Returns the clipping offset of the plotted data relative to the plot
+	 * area. Positive inset values result in clipping inside the plot area,
+	 * negative values result in clipping outside the plot area.
+	 * Specifying a {@code null} values will turn off clipping.
+	 * @return Clipping offset in pixels relative to the outline of the plot
+	 * area.
+	 */
+	public Insets2D getClippingOffset() {
+		return clippingOffset;
+	}
+
+	/**
+	 * Sets the clipping offset of the plotted data relative to the plot area.
+	 * Positive inset values result in clipping inside the plot area,
+	 * negative values result in clipping outside the plot area.
+	 * Specifying a {@code null} values will turn off clipping.
+	 * @param offset Clipping offset in pixels relative to the outline of the
+	 * plot area.
+	 */
+	public void setClippingArea(Insets2D offset) {
+		this.clippingOffset = offset;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/PlotNavigator.java

@@ -0,0 +1,447 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.navigation.AbstractNavigator;
+import org.xbib.graphics.graph.gral.navigation.NavigationEvent;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * <p>Abstract base class that can be used to control the zoom and panning of a
+ * plot. The navigator translates the interaction to operations on a defined
+ * set of axes: Zooming is translated as scaling, panning is done by uniformly
+ * changing the minimum and maximum values of the axes.</p>
+ *
+ * <p>Additionally, the actions can also be bound to a certain direction by
+ * defining a more restricted set of axes. The methods {@link #getDirection()}
+ * and {@link #setDirection(de.erichseifert.gral.navigation.NavigationDirection)}
+ * provide a convenient way for setting predefined sets of axes.</p>
+ */
+public abstract class PlotNavigator extends AbstractNavigator {
+	/** AbstractPlot that will be navigated. */
+	private final Plot plot;
+	/** Mapping of axis name to information on center and zoom. */
+	private final Map<String, NavigationInfo> infos;
+	/** Axes affected by navigation. */
+	private final List<String> axes;
+
+	/**
+	 * Data class for storing navigational information for an axis.
+	 */
+	protected static final class NavigationInfo {
+		/** Minimum value of the original axis. */
+		private final Number minOriginal;
+		/** Maximum value of the original axis. */
+		private final Number maxOriginal;
+		/** Center value of the original axis. */
+		private final double centerOriginal;
+		/** Current center value. */
+		private double center;
+		/** Current zoom level. */
+		private double zoom;
+
+		/**
+		 * Initializes a new {@code NavigationInfo} instance.
+		 * @param min Minimum value in axis units.
+		 * @param max Maximum value in axis units.
+		 * @param center Center in axis units.
+		 */
+		public NavigationInfo(Number min, Number max, double center) {
+			this.minOriginal = min;
+			this.maxOriginal = max;
+			this.centerOriginal = center;
+			this.center = centerOriginal;
+			this.zoom = 1.0;
+		}
+
+		/**
+		 * Returns the original minimum value.
+		 * @return Original minimum value.
+		 */
+		public Number getMinOriginal() {
+			return minOriginal;
+		}
+		/**
+		 * Returns the original maximum value.
+		 * @return Original maximum value.
+		 */
+		public Number getMaxOriginal() {
+			return maxOriginal;
+		}
+		/**
+		 * Returns the original center value.
+		 * @return Original center value.
+		 */
+		public double getCenterOriginal() {
+			return centerOriginal;
+		}
+
+		/**
+		 * Returns the current center value.
+		 * @return Current center value.
+		 */
+		public double getCenter() {
+			return center;
+		}
+		/**
+		 * Sets the current center value.
+		 * @param center New center value.
+		 */
+		public void setCenter(double center) {
+			this.center = center;
+		}
+
+		/**
+		 * Returns the current zoom factor.
+		 * @return Current zoom factor.
+		 */
+		public double getZoom() {
+			return zoom;
+		}
+		/**
+		 * Sets the current zoom factor.
+		 * @param zoom New zoom factor.
+		 */
+		public void setZoom(double zoom) {
+			this.zoom = zoom;
+		}
+	}
+
+	/**
+	 * Initializes a new instance that is responsible for zooming and panning
+	 * the axes with the specified names of the specified plot.
+	 * @param plot AbstractPlot to be zoomed and panned.
+	 * @param axesNames Names of the axes that should be controlled by this
+	 *        navigator.
+	 */
+	public PlotNavigator(Plot plot, List<String> axesNames) {
+		axes = new LinkedList<>();
+		infos = new HashMap<>();
+
+		this.plot = plot;
+
+		setAxes(axesNames);
+	}
+
+	/**
+	 * Initializes a new instance that is responsible for zooming and panning
+	 * the axes with the specified names of the specified plot.
+	 * @param plot AbstractPlot to be zoomed and panned.
+	 * @param axesNames Names of the axes that should be controlled by this
+	 *        navigator.
+	 */
+	public PlotNavigator(Plot plot, String... axesNames) {
+		this(plot, Arrays.asList(axesNames));
+	}
+
+	/**
+	 * Refreshes the values of all axis to reflect navigation actions.
+	 */
+	private void refresh() {
+		for (String axisName : getAxes()) {
+			NavigationInfo info = getInfo(axisName);
+			if (info == null) {
+				continue;
+			}
+
+			AxisRenderer renderer = getPlot().getAxisRenderer(axisName);
+			if (renderer == null) {
+				continue;
+			}
+
+			Axis axis = getPlot().getAxis(axisName);
+
+			// Original range in screen units
+			// Most up-to-date view coordinates (axis's layout) must be used
+			double minOrig = renderer.worldToView(
+				axis, info.getMinOriginal(), true);
+			double maxOrig = renderer.worldToView(
+				axis, info.getMaxOriginal(), true);
+			double rangeOrig = maxOrig - minOrig;
+
+			// New axis scale
+			double zoom = info.getZoom();
+			double range = rangeOrig/zoom;
+			double center = renderer.worldToView(axis, info.getCenter(), true);
+			Number min = renderer.viewToWorld(axis, center - 0.5*range, true);
+			Number max = renderer.viewToWorld(axis, center + 0.5*range, true);
+
+			// Change axis
+			axis.setRange(min, max);
+		}
+	}
+
+	/**
+	 * Returns the plot stored in this instance.
+	 * @return Stored plot object.
+	 */
+	protected Plot getPlot() {
+		return plot;
+	}
+
+	/**
+	 * Returns the current zoom level of the associated object.
+	 * @return Current zoom level.
+	 */
+	public double getZoom() {
+		double zoom = 0.0;
+		int count = 0;
+		for (String axisName : getAxes()) {
+			NavigationInfo info = getInfo(axisName);
+			if (info == null) {
+				continue;
+			}
+			if (!MathUtils.isCalculatable(info.getZoom())) {
+				continue;
+			}
+			zoom += info.getZoom();
+			count++;
+		}
+		return zoom / count;
+	}
+
+	/**
+	 * Sets the zoom level of the associated object to the specified value.
+	 * @param zoomNew New zoom level.
+	 */
+	public void setZoom(double zoomNew) {
+		if (!isZoomable() || (zoomNew <= 0.0) ||
+				!MathUtils.isCalculatable(zoomNew)) {
+			return;
+		}
+		double zoomOld = getZoom();
+		zoomNew = MathUtils.limit(zoomNew, getZoomMin(), getZoomMax());
+		if (zoomOld == zoomNew) {
+			return;
+		}
+		for (String axisName : getAxes()) {
+			NavigationInfo info = getInfo(axisName);
+			if (info == null) {
+				continue;
+			}
+			info.setZoom(zoomNew);
+		}
+		NavigationEvent<Double> event =
+				new NavigationEvent<>(this, zoomOld, zoomNew);
+		fireZoomChanged(event);
+		refresh();
+	}
+
+	/**
+	 * Returns the current center point. The returned point contains value in
+	 * world units.
+	 * @return Center point in world units.
+	 */
+	public PointND<? extends Number> getCenter() {
+		List<String> axesNames = getAxes();
+		Double[] centerCoords = new Double[axesNames.size()];
+		int axisIndex = 0;
+		for (String axisName : axesNames) {
+			NavigationInfo info = getInfo(axisName);
+			if (info != null) {
+				double axisCenter = info.getCenter();
+				centerCoords[axisIndex] = axisCenter;
+			}
+			axisIndex++;
+		}
+		return new PointND<>(centerCoords);
+	}
+
+	/**
+	 * Sets a new center point. The values of the point are in world units.
+	 * @param center New center point in world units.
+	 */
+	public void setCenter(PointND<? extends Number> center) {
+		if (!isPannable()) {
+			return;
+		}
+		PointND<? extends Number> centerOld = getCenter();
+		if (centerOld.equals(center)) {
+			return;
+		}
+		List<String> axesNames = getAxes();
+		int axisIndex = 0;
+		for (String axisName : axesNames) {
+			NavigationInfo info = getInfo(axisName);
+			if (info != null) {
+				Number centerCoordNew = center.get(axisIndex);
+				info.setCenter(centerCoordNew.doubleValue());
+			}
+			axisIndex++;
+		}
+
+		NavigationEvent<PointND<? extends Number>> event =
+				new NavigationEvent<>(this, centerOld, center);
+		fireCenterChanged(event);
+		refresh();
+	}
+
+	/**
+	 * Moves the center by the relative values of the specified point.
+	 * The values of the point are in screen units.
+	 * @param deltas Relative values to use for panning.
+	 */
+	public void pan(PointND<? extends Number> deltas) {
+		if (!isPannable()) {
+			return;
+		}
+		PointND<? extends Number> centerOld = getCenter();
+		Double[] centerCoords = new Double[centerOld.getDimensions()];
+		int axisIndex = 0;
+		for (String axisName : getAxes()) {
+			NavigationInfo info = getInfo(axisName);
+			if (info != null) {
+				double delta = getDimensionValue(axisName, deltas).doubleValue();
+				AxisRenderer renderer =
+					getPlot().getAxisRenderer(axisName);
+				if (renderer != null) {
+					boolean swapped = renderer.isShapeDirectionSwapped();
+					if (swapped) {
+						delta = -delta;
+					}
+					Axis axis = getPlot().getAxis(axisName);
+					// Fetch current center on screen
+					double center = renderer.worldToView(
+						axis, info.getCenter(), true);
+					// Move center and convert it to axis coordinates
+					Number centerNew = renderer.viewToWorld(
+						axis, center - delta, true);
+					// Change axis (world units)
+					info.setCenter(centerNew.doubleValue());
+					centerCoords[axisIndex] = centerNew.doubleValue();
+				}
+			}
+			axisIndex++;
+		}
+		PointND<? extends Number> centerNew = new PointND<>(centerCoords);
+		NavigationEvent<PointND<? extends Number>> event =
+				new NavigationEvent<>(this, centerOld, centerNew);
+		fireCenterChanged(event);
+		refresh();
+	}
+
+	/**
+	 * Sets the current state as the default state of the object.
+	 * Resetting the navigator will then return to the default state.
+	 */
+	public void setDefaultState() {
+		infos.clear();
+		for (String axisName : getAxes()) {
+			Axis axis = getPlot().getAxis(axisName);
+			if (axis == null) {
+				continue;
+			}
+			double min;
+			double max;
+			Number center = 0.0;
+			AxisRenderer renderer = getPlot().getAxisRenderer(axisName);
+			if (renderer != null && axis.isValid()) {
+				min = renderer.worldToView(axis, axis.getMin(), false);
+				max = renderer.worldToView(axis, axis.getMax(), false);
+				if (MathUtils.isCalculatable(min) && MathUtils.isCalculatable(max)) {
+					center = renderer.viewToWorld(axis, (min + max)/2.0, false);
+				}
+			}
+			NavigationInfo info = new NavigationInfo(
+				axis.getMin(), axis.getMax(), center.doubleValue());
+			infos.put(axisName, info);
+		}
+	}
+
+	/**
+	 * Sets the object's position and zoom level to the default state.
+	 */
+	public void reset() {
+		double zoomOld = getZoom();
+		double zoomNew = 1.0;
+		PointND<? extends Number> centerOld = getCenter();
+
+		List<String> axesNames = getAxes();
+		Double[] centerCoordsOriginal = new Double[centerOld.getDimensions()];
+		int axisIndex = 0;
+		for (String axisName : axesNames) {
+			NavigationInfo info = getInfo(axisName);
+			if (info != null) {
+				double centerCoordOriginal = info.getCenterOriginal();
+				centerCoordsOriginal[axisIndex] = centerCoordOriginal;
+
+				info.setCenter(centerCoordOriginal);
+				info.setZoom(zoomNew);
+			}
+			axisIndex++;
+		}
+		PointND<Double> centerNew = new PointND<>(centerCoordsOriginal);
+
+		NavigationEvent<PointND<? extends Number>> panEvent =
+				new NavigationEvent<>(this, centerOld, centerNew);
+		fireCenterChanged(panEvent);
+
+		NavigationEvent<Double> zoomEvent =
+				new NavigationEvent<>(this, zoomOld, 1.0);
+		fireZoomChanged(zoomEvent);
+
+		refresh();
+	}
+
+	/**
+	 * Returns navigational information for the axis with specified name.
+	 * @param axisName Axis name.
+	 * @return Navigational information.
+	 */
+	protected NavigationInfo getInfo(String axisName) {
+		return infos.get(axisName);
+	}
+
+	/**
+	 * Returns the names of all axes handled by this object.
+	 * @return Names of all axes handled by this object.
+	 */
+	protected List<String> getAxes() {
+		return Collections.unmodifiableList(axes);
+	}
+
+	/**
+	 * Sets the names of the axes that should be handled by this object.
+	 * @param axesNames Names of the axes that should be handled.
+	 */
+	protected void setAxes(List<String> axesNames) {
+		axes.clear();
+		axes.addAll(axesNames);
+		setDefaultState();
+	}
+
+	/**
+	 * Sets the names of the axes that should be handled by this object.
+	 * @param axesNames Names of the axes that should be handled.
+	 */
+	protected void setAxes(String... axesNames) {
+		setAxes(Arrays.asList(axesNames));
+	}
+
+	/**
+	 * Returns the number dimensions the associated plot can handle. For a
+	 * one-dimensional plot like {@link PiePlot} this is 1, for a
+	 * two-dimensional plot like {@link XYPlot} this is 2, and so on.
+	 * @return Number of dimensions the associated plot can handle.
+	 */
+	protected abstract int getDimensions();
+
+	/**
+	 * Return the index that can be used to access data for the axis with the
+	 * specified name. The returned index must be larger than or equal to 0 and
+	 * smaller than the result of {@link #getDimensions()}.
+	 * @param axisName Name of the axis.
+	 * @param values Data values.
+	 * @return Dimension index.
+	 */
+	protected abstract Number getDimensionValue(
+		String axisName, PointND<? extends Number> values);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/RasterPlot.java

@@ -0,0 +1,400 @@
+package org.xbib.graphics.graph.gral.plots;
+
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+
+import org.xbib.graphics.graph.gral.data.DataSource;
+import org.xbib.graphics.graph.gral.data.DataTable;
+import org.xbib.graphics.graph.gral.data.Row;
+import org.xbib.graphics.graph.gral.data.statistics.Statistics;
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.plots.colors.ColorMapper;
+import org.xbib.graphics.graph.gral.plots.colors.ContinuousColorMapper;
+import org.xbib.graphics.graph.gral.plots.colors.Grayscale;
+import org.xbib.graphics.graph.gral.plots.points.AbstractPointRenderer;
+import org.xbib.graphics.graph.gral.plots.points.PointData;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * <p>Class that displays two coordinate values and a value as a raster of
+ * boxes. The data source must provide at least three columns:</p>
+ * <ul>
+ *   <li>x coordinate</li>
+ *   <li>y coordinate</li>
+ *   <li>value</li>
+ * </ul>
+ * <p>The method {@link #createRasterData(DataSource)} can be used to convert
+ * a matrix of values to the (coordinates, value) format.</p>
+ *
+ * <p>To create a new {@code RasterPlot} simply create a new instance using
+ * a suitable data source. Example:</p>
+ * <pre>
+ * DataTable data = new DataTable(Double.class, Double.class);
+ * data.add(10.98, -12.34);
+ * data.add( 7.65,  45.67);
+ * data.add(43.21,  89.01);
+ * DataSource rasterData = RasterPlot.createRasterData(data);
+ * RasterPlot plot = new RasterPlot(rasterData);
+ * </pre>
+ */
+public class RasterPlot extends XYPlot {
+	/** Version id for serialization. */
+	private static final long serialVersionUID = 5844862286358250831L;
+
+	/** Offset of the raster pixels to the origin. */
+	private final Point2D offset;
+	/** Size of the raster pixels. */
+	private final Dimension2D distance;
+	/** Color mapping to fill the raster pixels. */
+	private ColorMapper colors;
+
+	/**
+	 * Class that renders the grid points of a {@code RasterPlot}.
+	 */
+	protected static class RasterRenderer extends AbstractPointRenderer {
+		/** Version id for serialization. */
+		private static final long serialVersionUID = 1266585364126459761L;
+
+		/** Plot specific settings. */
+		private final RasterPlot plot;
+
+		/** Horizontal position of the current raster pixel. */
+		private int xColumn;
+		/** Vertical position of the current raster pixel. */
+		private int yColumn;
+		/** Value of the current raster pixel. */
+		private int valueColumn;
+
+		/**
+		 * Constructor that creates a new instance and initializes it with a
+		 * plot as data provider. The default columns for (x, y, value) are set
+		 * to (0, 1, 2)
+		 * @param plot Plot storing global settings.
+		 */
+		public RasterRenderer(RasterPlot plot) {
+			this.plot = plot;
+			xColumn = 0;
+			yColumn = 1;
+			valueColumn = 2;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the x coordinate
+		 * of a point.
+		 * @return Index of the column for the x coordinate of a point.
+		 */
+		public int getXColumn() {
+			return xColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the x coordinate
+		 * of a point.
+		 * @param columnIndex Index of the column for the x coordinate of a point.
+		 */
+		public void setXColumn(int columnIndex) {
+			this.xColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the y coordinate
+		 * of a point.
+		 * @return Index of the column for the y coordinate of a point.
+		 */
+		public int getYColumn() {
+			return yColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the y coordinate
+		 * of a point.
+		 * @param columnIndex Index of the column for the y coordinate of a point.
+		 */
+		public void setYColumn(int columnIndex) {
+			this.yColumn = columnIndex;
+		}
+
+		/**
+		 * Returns the index of the column which is used for the value of a
+		 * point.
+		 * @return Index of the column for the value of a point.
+		 */
+		@Override
+		public int getValueColumn() {
+			return valueColumn;
+		}
+
+		/**
+		 * Sets the index of the column which will be used for the value of a
+		 * point.
+		 * @param columnIndex Index of the column for the value of a point.
+		 */
+		@Override
+		public void setValueColumn(int columnIndex) {
+			this.valueColumn = columnIndex;
+		}
+
+		@Override
+		public Drawable getPoint(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+				/** Version id for serialization. */
+				private static final long serialVersionUID = -1136689797647794969L;
+
+				public void draw(DrawingContext context) {
+					RasterRenderer renderer = RasterRenderer.this;
+
+					Axis axisX = data.axes.get(0);
+					Axis axisY = data.axes.get(1);
+					AxisRenderer axisXRenderer = data.axisRenderers.get(0);
+					AxisRenderer axisYRenderer = data.axisRenderers.get(1);
+					Row row = data.row;
+
+					int colX = renderer.getXColumn();
+					if (colX < 0 || colX >= row.size() || !row.isColumnNumeric(colX)) {
+						return;
+					}
+					int colY = renderer.getYColumn();
+					if (colY < 0 || colY >= row.size() || !row.isColumnNumeric(colY)) {
+						return;
+					}
+					int colValue = renderer.getValueColumn();
+					if (colValue < 0 || colValue >= row.size() || !row.isColumnNumeric(colValue)) {
+						return;
+					}
+
+					double valueX = ((Number) row.get(colX)).doubleValue();
+					double valueY = ((Number) row.get(colY)).doubleValue();
+					Number value = (Number) row.get(colValue);
+
+					// Pixel dimensions
+					double xMin = axisXRenderer
+						.getPosition(axisX, valueX - 0.5, true, false)
+						.get(PointND.X);
+					double xMax = axisXRenderer
+						.getPosition(axisX, valueX + 0.5, true, false)
+						.get(PointND.X);
+					double width = Math.abs(xMax - xMin) + 1.0;
+					double yMin = axisYRenderer
+						.getPosition(axisY, valueY - 0.5, true, false)
+						.get(PointND.Y);
+					double yMax = axisYRenderer
+						.getPosition(axisY, valueY + 0.5, true, false)
+						.get(PointND.Y);
+					double height = Math.abs(yMax - yMin) + 1.0;
+
+					// Create shape for pixel
+					// The origin of all shapes is (boxX, boxY)
+					Rectangle2D shapeBounds = shape.getBounds2D();
+					AffineTransform tx = new AffineTransform();
+					tx.scale(width/shapeBounds.getWidth(), height/shapeBounds.getHeight());
+					tx.translate(-shapeBounds.getMinX(), -shapeBounds.getMinY());
+					Shape pixel = tx.createTransformedShape(shape);
+
+					// Paint pixel
+					Graphics2D graphics = context.getGraphics();
+					ColorMapper colorMapper = plot.getColors();
+					Paint paint;
+					if (colorMapper instanceof ContinuousColorMapper) {
+						paint = ((ContinuousColorMapper) colorMapper)
+							.get(value.doubleValue());
+					} else if (colorMapper != null) {
+						Integer index = value.intValue();
+						paint = colorMapper.get(index);
+					} else {
+						paint = Color.BLACK;
+					}
+					GraphicsUtils.fillPaintedShape(
+						graphics, pixel, paint, pixel.getBounds2D());
+				}
+			};
+		}
+
+		/**
+		 * Returns a {@code Shape} instance that can be used for further
+		 * calculations.
+		 * @param data Information on axes, renderers, and values.
+		 * @return Outline that describes the point's shape.
+		 */
+		public Shape getPointShape(PointData data) {
+			return getShape();
+		}
+
+		/**
+		 * Returns a graphical representation of the value label to be drawn for
+		 * the specified data value.
+		 * @param data Information on axes, renderers, and values.
+		 * @param shape Outline that describes the bounds for the value label.
+		 * @return Component that can be used to draw the value label.
+		 */
+		public Drawable getValue(final PointData data, final Shape shape) {
+			return new AbstractDrawable() {
+
+				public void draw(DrawingContext context) {
+					// TODO Implement rendering of value label
+				}
+			};
+		}
+	}
+
+	/**
+	 * Initializes a new box-and-whisker plot with the specified data source.
+	 * @param data Data to be displayed.
+	 */
+	public RasterPlot(DataSource data) {
+		offset = new Point2D.Double();
+		distance = new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(1.0, 1.0);
+		colors = new Grayscale();
+
+		((XYPlotArea2D) getPlotArea()).setMajorGridX(false);
+		((XYPlotArea2D) getPlotArea()).setMajorGridY(false);
+		//getAxisRenderer(AXIS_X).setSetting(AxisRenderer.TICKS, false);
+		//getAxisRenderer(AXIS_Y).setSetting(AxisRenderer.TICKS, false);
+		getAxisRenderer(AXIS_X).setIntersection(-Double.MAX_VALUE);
+		getAxisRenderer(AXIS_Y).setIntersection(-Double.MAX_VALUE);
+
+		// Store data
+		add(data);
+
+		// Adjust axes to the data series
+		autoscaleAxes();
+	}
+
+	@Override
+	public void autoscaleAxis(String axisName) {
+		if (AXIS_X.equals(axisName) || AXIS_Y.equals(axisName)) {
+			Dimension2D dist = getDistance();
+			// In case we get called before settings defaults have been set,
+			// just set distance to a sane default
+			if (dist == null) {
+				dist = new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(1.0, 1.0);
+			}
+
+			Axis axis = getAxis(axisName);
+			if (axis == null || !axis.isAutoscaled()) {
+				return;
+			}
+
+			double min = getAxisMin(axisName);
+			double max = getAxisMax(axisName);
+			if (AXIS_X.equals(axisName)) {
+				axis.setRange(min, max + dist.getWidth());
+			} else if (AXIS_Y.equals(axisName)) {
+				axis.setRange(min - dist.getHeight(), max);
+			}
+		} else {
+			super.autoscaleAxis(axisName);
+		}
+	}
+
+	/**
+	 * Takes a matrix of values and creates a new data source that stores the
+	 * values in (x, y, value) format.
+	 * @param data Original data source with values in each cell.
+	 * @return New data source with (x, y, value) columns
+	 */
+	@SuppressWarnings("unchecked")
+	public static DataSource createRasterData(DataSource data) {
+		if (data == null) {
+			throw new NullPointerException("Cannot convert null data source.");
+		}
+
+		DataTable coordsValueData =
+			new DataTable(Double.class, Double.class, Double.class);
+
+		// Generate pixel data with (x, y, value)
+		double min = ((Number) data.getRowStatistics(Statistics.MIN).
+				getColumnStatistics(Statistics.MIN).get(0, 0)).doubleValue();
+		double max = ((Number) data.getRowStatistics(Statistics.MAX).
+				getColumnStatistics(Statistics.MAX).get(0, 0)).doubleValue();
+		double range = max - min;
+		int i = 0;
+		for (Comparable<?> cell : data) {
+			int x =  i%data.getColumnCount();
+			int y = -i/data.getColumnCount();
+			double v = Double.NaN;
+			if (cell instanceof Number) {
+				Number numericCell = (Number) cell;
+				v = (numericCell.doubleValue() - min) / range;
+			}
+			coordsValueData.add((double) x, (double) y, v);
+			i++;
+		}
+		return coordsValueData;
+	}
+
+	@Override
+	public void add(int index, DataSource source, boolean visible) {
+		if (getData().size() > 0) {
+			throw new IllegalArgumentException(
+				"This plot type only supports a single data source."); //$NON-NLS-1$
+		}
+		// Add data source
+		super.add(index, source, visible);
+		// Adjust rendering
+		// FIXME: Overwrites possible present point and line renderers
+		setLineRenderers(source, null);
+		setPointRenderers(source, new RasterRenderer(this));
+	}
+
+	/**
+	 * Returns the horizontal and vertical offset of the raster from the
+	 * origin.
+	 * @return Horizontal and vertical offset of the raster from the origin.
+	 */
+	public Point2D getOffset() {
+		return offset;
+	}
+
+	/**
+	 * Sets the horizontal and vertical offset of the raster from the
+	 * origin.
+	 * @param offset Horizontal and vertical offset of the raster from the
+	 * origin.
+	 */
+	public void setOffset(Point2D offset) {
+		this.offset.setLocation(offset);
+	}
+
+	/**
+	 * Returns the horizontal and vertical distance of the raster elements.
+	 * @return Horizontal and vertical distance of the raster elements.
+	 */
+	public Dimension2D getDistance() {
+		return distance;
+	}
+
+	/**
+	 * Returns the horizontal and vertical distance of the raster elements.
+	 * @param distance Horizontal and vertical distance of the raster elements.
+	 */
+	public void setDistance(Dimension2D distance) {
+		this.distance.setSize(distance);
+	}
+
+	/**
+	 * Returns the object which is used to map pixel values to colors.
+	 * @return Object which is used to map pixel values to colors.
+	 */
+	public ColorMapper getColors() {
+		return colors;
+	}
+
+	/**
+	 * Sets the object which will be used to map pixel values to colors.
+	 * @param colors Object which will be used to map pixel values to colors.
+	 */
+	public void setColors(ColorMapper colors) {
+		this.colors = colors;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/areas/AbstractAreaRenderer.java

@@ -0,0 +1,62 @@
+package org.xbib.graphics.graph.gral.plots.areas;
+
+import java.awt.Color;
+import java.awt.Paint;
+
+/**
+ * <p>Abstract class that renders an area in two-dimensional space.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Punching data points out of the area's shape</li>
+ *   <li>Administration of settings</li>
+ * </ul>
+ */
+public abstract class AbstractAreaRenderer implements AreaRenderer {
+
+	/** Gap between points and the area. */
+	private double gap;
+	/** Decides whether the shape of the gap between points and the area is
+	 * rounded. */
+	private boolean gapRounded;
+	/** Paint to fill the area. */
+	private Paint color;
+
+	/**
+	 * Initializes a new instance with default settings.
+	 */
+	public AbstractAreaRenderer() {
+		gap = 0.0;
+		gapRounded = false;
+		color = Color.GRAY;
+	}
+
+	@Override
+	public double getGap() {
+		return gap;
+	}
+
+	@Override
+	public void setGap(double gap) {
+		this.gap = gap;
+	}
+
+	@Override
+	public boolean isGapRounded() {
+		return gapRounded;
+	}
+
+	@Override
+	public void setGapRounded(boolean gapRounded) {
+		this.gapRounded = gapRounded;
+	}
+
+	@Override
+	public Paint getColor() {
+		return color;
+	}
+
+	@Override
+	public void setColor(Paint color) {
+		this.color = color;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/areas/AreaRenderer.java

@@ -0,0 +1,66 @@
+package org.xbib.graphics.graph.gral.plots.areas;
+
+import java.awt.Paint;
+import java.awt.Shape;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.plots.DataPoint;
+
+/**
+ * Interface for renderers that display areas in plots.
+ */
+public interface AreaRenderer {
+	/**
+	 * Returns the shape used for rendering the area of a data points.
+	 * @param points Data points.
+	 * @return Geometric shape for the area of the specified data points.
+	 */
+	Shape getAreaShape(List<DataPoint> points);
+
+	/**
+	 * Returns the graphical representation to be drawn for the specified data
+	 * points.
+	 * @param points Points that define the shape of the area.
+	 * @param shape Geometric shape of the area.
+	 * @return Representation of the area.
+	 */
+	Drawable getArea(List<DataPoint> points, Shape shape);
+
+	// TODO: Mention which unit the Gap property has (pixels?)
+	/**
+	 * Returns the value for the gap between the area and a data point.
+	 * @return Gap between area and data point.
+	 */
+	double getGap();
+
+	/**
+	 * Sets the value for the gap between the area and a data point.
+	 * @param gap Gap between area and data point.
+	 */
+	void setGap(double gap);
+
+	/**
+	 * Returns whether the gaps should have rounded corners.
+	 * @return {@code true}, if the gaps should have rounded corners.
+	 */
+	boolean isGapRounded();
+
+	/**
+	 * Sets a value which decides whether the gaps should have rounded corners.
+	 * @param gapRounded {@code true}, if the gaps should have rounded corners.
+	 */
+	void setGapRounded(boolean gapRounded);
+
+	/**
+	 * Returns the paint used to fill the area shape.
+	 * @return Paint for the area shape.
+	 */
+	Paint getColor();
+
+	/**
+	 * Sets the paint used to fill the area shape.
+	 * @param color Paint for the area shape.
+	 */
+	void setColor(Paint color);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/areas/DefaultAreaRenderer2D.java

@@ -0,0 +1,96 @@
+package org.xbib.graphics.graph.gral.plots.areas;
+
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.geom.Path2D;
+import java.awt.geom.Point2D;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.plots.DataPoint;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * Default two-dimensional implementation of the {@code AreaRenderer}
+ * interface.
+ */
+public class DefaultAreaRenderer2D extends AbstractAreaRenderer {
+
+	/**
+	 * Returns the graphical representation to be drawn for the specified
+	 * data points.
+	 * @param points Points to be used for creating the area.
+	 * @param shape Geometric shape of the area.
+	 * @return Representation of the area.
+	 */
+	public Drawable getArea(final List<DataPoint> points, final Shape shape) {
+		return new AbstractDrawable() {
+
+			/**
+			 * Draws the {@code Drawable} with the specified drawing context.
+			 * @param context Environment used for drawing
+			 */
+			public void draw(DrawingContext context) {
+				Paint paint = DefaultAreaRenderer2D.this.getColor();
+				GraphicsUtils.fillPaintedShape(context.getGraphics(),
+					shape, paint, null);
+			}
+		};
+	}
+
+	/**
+	 * Returns the shape used for rendering the area of a data points.
+	 * @param points Data points.
+	 * @return Geometric shape for the area of the specified data points.
+	 */
+	public Shape getAreaShape(List<DataPoint> points) {
+		if (points.isEmpty() || points.get(0) == null) {
+			return null;
+		}
+
+		Axis axisY = points.get(0).data.axes.get(1);
+		AxisRenderer axisRendererY = points.get(0).data.axisRenderers.get(1);
+
+		double axisYMin = axisY.getMin().doubleValue();
+		double axisYMax = axisY.getMax().doubleValue();
+		double axisYOrigin = MathUtils.limit(0.0, axisYMin, axisYMax);
+
+		PointND<Double> posOrigin = null;
+		if (axisRendererY != null) {
+			posOrigin = axisRendererY.getPosition(
+					axisY, axisYOrigin, true, false);
+		}
+
+		Path2D shape = new Path2D.Double();
+		if (posOrigin == null) {
+			return shape;
+		}
+
+		double posYOrigin = posOrigin.get(PointND.Y);
+		double x = 0.0;
+		double y = 0.0;
+
+		for (DataPoint p: points) {
+			Point2D pos = p.position.getPoint2D();
+			x = pos.getX();
+			y = pos.getY();
+			if (shape.getCurrentPoint() == null) {
+				shape.moveTo(x, posYOrigin);
+			}
+			shape.lineTo(x, y);
+		}
+
+		if (shape.getCurrentPoint() != null) {
+			shape.lineTo(x, posYOrigin);
+			shape.closePath();
+		}
+
+		return shape;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/areas/LineAreaRenderer2D.java

@@ -0,0 +1,113 @@
+package org.xbib.graphics.graph.gral.plots.areas;
+
+import java.awt.BasicStroke;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.awt.geom.Path2D;
+import java.awt.geom.Point2D;
+import java.util.List;
+
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.plots.DataPoint;
+import org.xbib.graphics.graph.gral.plots.axes.Axis;
+import org.xbib.graphics.graph.gral.plots.axes.AxisRenderer;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * Default two-dimensional implementation of the {@code AreaRenderer} interface
+ * that draws lines from data points to the main axis.
+ */
+public class LineAreaRenderer2D extends AbstractAreaRenderer {
+
+	/** Stroke that is used to draw the lines from the data points to the
+	 * axis. */
+	private Stroke stroke;
+
+	/**
+	 * Standard constructor that initializes a new instance.
+	 */
+	public LineAreaRenderer2D() {
+		stroke = new BasicStroke(1f);
+	}
+
+	/**
+	 * Returns the graphical representation to be drawn for the specified data
+	 * points.
+	 * @param points Points that define the shape of the area.
+	 * @param shape Geometric shape of the area.
+	 * @return Representation of the area.
+	 */
+	public Drawable getArea(final List<DataPoint> points, final Shape shape) {
+		return new AbstractDrawable() {
+
+			/**
+			 * Draws the {@code Drawable} with the specified drawing context.
+			 * @param context Environment used for drawing
+			 */
+			public void draw(DrawingContext context) {
+				Paint paint = LineAreaRenderer2D.this.getColor();
+				GraphicsUtils.fillPaintedShape(context.getGraphics(),
+					shape, paint, null);
+			}
+		};
+	}
+
+	/**
+	 * Returns the shape used for rendering the area of a data points.
+	 * @param points Data points.
+	 * @return Geometric shape for the area of the specified data points.
+	 */
+	public Shape getAreaShape(List<DataPoint> points) {
+		if (points.isEmpty() || points.get(0) == null) {
+			return null;
+		}
+
+		Axis axisY = points.get(0).data.axes.get(1);
+		AxisRenderer axisRendererY = points.get(0).data.axisRenderers.get(1);
+
+		double axisYMin = axisY.getMin().doubleValue();
+		double axisYMax = axisY.getMax().doubleValue();
+		double axisYOrigin = MathUtils.limit(0.0, axisYMin, axisYMax);
+		double posYOrigin = 0.0;
+		if (axisRendererY != null) {
+			posYOrigin = axisRendererY.getPosition(
+					axisY, axisYOrigin, true, false).get(PointND.Y);
+		}
+		Path2D shape = new Path2D.Double();
+		double x = 0.0;
+		double y = 0.0;
+		for (DataPoint p : points) {
+			Point2D pos = p.position.getPoint2D();
+			x = pos.getX();
+			y = pos.getY();
+			shape.moveTo(x, y);
+			shape.lineTo(x, posYOrigin);
+		}
+
+		Stroke stroke = getStroke();
+		return stroke.createStrokedShape(shape);
+	}
+
+	/**
+	 * Returns the stroke that is used to draw the lines from the
+	 * data points to the axis.
+	 * @return Stroke for line drawing.
+	 */
+	public Stroke getStroke() {
+		return stroke;
+	}
+
+	/**
+	 * Set the stroke that is used to draw the lines from the
+	 * data points to the axis.
+	 * @param stroke Stroke for line drawing.
+	 */
+	public void setStroke(Stroke stroke) {
+		this.stroke = stroke;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/axes/AbstractAxisRenderer2D.java

@@ -0,0 +1,939 @@
+package org.xbib.graphics.graph.gral.plots.axes;
+
+import java.awt.BasicStroke;
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Dimension2D;
+import java.awt.geom.Line2D;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.text.Format;
+import java.text.NumberFormat;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.xbib.graphics.graph.gral.graphics.AbstractDrawable;
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.DrawingContext;
+import org.xbib.graphics.graph.gral.graphics.Label;
+import org.xbib.graphics.graph.gral.plots.axes.Tick.TickType;
+import org.xbib.graphics.graph.gral.util.GeometryUtils;
+import org.xbib.graphics.graph.gral.util.GraphicsUtils;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * <p>Abstract class that provides function for rendering axes in
+ * two-dimensional space.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Calculating tick positions of an axis</li>
+ *   <li>Calculating tick normals</li>
+ *   <li>Administration of settings</li>
+ * </ul>
+ */
+public abstract class AbstractAxisRenderer2D implements AxisRenderer {
+	/** Line segments approximating the shape of the axis. */
+	private Line2D[] shapeLines;
+	/** Normals of the line segments approximating the axis. */
+	private Point2D[] shapeLineNormals;
+	/** Lengths of the line segments approximating the axis. */
+	private double[] shapeSegmentLengths;
+	/** Length of the axis up to a certain approximating line segment. */
+	private double[] shapeSegmentLengthsAccumulated;
+
+	/** Intersection point of the axis. */
+	private Number intersection;
+	/** Shape used for drawing. */
+	private Shape shape;
+	/** Decides whether the shape is drawn. */
+	private boolean shapeVisible;
+	/** Decides whether the shape normals are orientated clockwise. */
+	private boolean shapeNormalOrientationClockwise;
+	/** Paint used to draw axis shape, ticks, and labels. */
+	private Paint shapeColor;
+	/** Stroke used for drawing the axis shape. */
+	// Property will be serialized using a wrapper
+	private transient Stroke shapeStroke;
+	/** Decides whether the axis direction will be changed. */
+	private boolean shapeDirectionSwapped;
+
+	/** Decides whether major ticks are drawn. */
+	private boolean ticksVisible;
+	/** Distance on axis in which major ticks are drawn. */
+	private Number tickSpacing;
+	/** Decides whether automatic tick spacing is enabled. */
+	private boolean ticksAutoSpaced;
+	/** Tick length relative to the font */
+	private double tickLength;
+	/** Stroke which is used to draw all major ticks. */
+	// Property will be serialized using a wrapper
+	private transient Stroke tickStroke;
+	/** Alignment of major ticks relative to the axis. */
+	private double tickAlignment;
+	/** Font used to display the text of major ticks. */
+	private Font tickFont;
+	/** Paint used to draw the shapes of major ticks. */
+	private Paint tickColor;
+	/** Decides whether tick labels will be shown. */
+	private boolean tickLabelsVisible;
+	/** Format which converts the tick values to labels. */
+	private Format tickLabelFormat;
+	/** Distance between labels and ticks relative to the font height. */
+	private double tickLabelDistance;
+	/** Decides whether the tick labels are drawn outside of the plot. */
+	private boolean tickLabelsOutside;
+	/** Tick label rotation in degrees. */
+	private double tickLabelRotation;
+
+	/** Decides whether minor ticks are drawn. */
+	private boolean minorTickVisible;
+	/** Number of minor ticks between two major ticks. */
+	private int minorTicksCount;
+	/** Tick length relative to font height.*/
+	private double minorTickLength;
+	/** Stroke used to draw all minor ticks. */
+	// Property will be serialized using a wrapper
+	private transient Stroke minorTickStroke;
+	/** Minor tick alignment relative to the axis. */
+	private double minorTickAlignment;
+	/** Paint used to draw the shapes of minor ticks. */
+	private Paint minorTickColor;
+
+	/** Custom labels containing their respective position and text. */
+	private final Map<Double, String> customTicks;
+	/** Label text of the axis. */
+	private Label label;
+	/** Distance relative to font height. */
+	private double labelDistance;
+
+	/**
+	 * Initializes a new instance with default settings.
+	 */
+	public AbstractAxisRenderer2D() {
+		intersection = 0.0;
+		// The direction must defined as swapped before the shape is evaluated.
+		shapeDirectionSwapped = false;
+		shape = new Line2D.Double(0.0, 0.0, 1.0, 0.0);
+		evaluateShape(shape);
+
+		shapeVisible = true;
+		shapeNormalOrientationClockwise = false;
+		shapeStroke = new BasicStroke();
+		shapeColor = Color.BLACK;
+
+		ticksVisible = true;
+		tickSpacing = 0.0;
+		ticksAutoSpaced = false;
+		tickLength = 1.0;
+		tickStroke = new BasicStroke();
+		tickAlignment = 0.5;
+		tickFont = Font.decode(null);
+		tickColor = Color.BLACK;
+
+		tickLabelsVisible = true;
+		tickLabelFormat = NumberFormat.getInstance();
+		tickLabelDistance = 1.0;
+		tickLabelsOutside = true;
+		tickLabelRotation = 0.0;
+
+		customTicks = new HashMap<>();
+
+		minorTickVisible = true;
+		minorTicksCount = 1;
+		minorTickLength = 0.5;
+		minorTickStroke = new BasicStroke();
+		minorTickAlignment = 0.5;
+		minorTickColor = Color.BLACK;
+
+		label = new Label();
+		labelDistance = 1.0;
+	}
+
+	/**
+	 * Returns a component that displays the specified axis.
+	 * @param axis axis to be displayed
+	 * @return component displaying the axis
+	 * @see Axis
+	 */
+	public Drawable getRendererComponent(final Axis axis) {
+		return new AbstractDrawable() {
+			/** Version id for serialization. */
+			private static final long serialVersionUID1 = 3605211198378801694L;
+
+			/**
+			 * Draws the {@code Drawable} with the specified drawing context.
+			 * @param context Environment used for drawing
+			 */
+			public void draw(DrawingContext context) {
+				if (shapeLines == null || shapeLines.length == 0) {
+					return;
+				}
+
+				AbstractAxisRenderer2D renderer = AbstractAxisRenderer2D.this;
+				Graphics2D graphics = context.getGraphics();
+
+				// Remember old state of Graphics2D instance
+				AffineTransform txOrig = graphics.getTransform();
+				graphics.translate(getX(), getY());
+				Stroke strokeOld = graphics.getStroke();
+				Paint paintOld = graphics.getPaint();
+
+				// Draw axis shape
+				Paint axisPaint = renderer.getShapeColor();
+				Stroke axisStroke = renderer.getShapeStroke();
+				boolean isShapeVisible = renderer.isShapeVisible();
+				if (isShapeVisible) {
+					Shape shape1 = renderer.getShape();
+					GraphicsUtils.drawPaintedShape(
+							graphics, shape1, axisPaint, null, axisStroke);
+				}
+
+				double fontSize =
+					renderer.getTickFont().getSize2D();
+
+				// Draw ticks
+				boolean drawTicksMajor = renderer.isTicksVisible();
+				boolean drawTicksMinor = renderer.isMinorTicksVisible();
+				if (drawTicksMajor || (drawTicksMajor && drawTicksMinor)) {
+					// Calculate tick positions (in pixel coordinates)
+					List<Tick> ticks = getTicks(axis);
+
+					boolean isTickLabelVisible =
+						renderer.isTickLabelsVisible();
+					boolean isTickLabelOutside = renderer.isTickLabelsOutside();
+					double tickLabelRotation1 = renderer.getTickLabelRotation();
+					double tickLabelDist = renderer.getTickLabelDistanceAbsolute();
+					Line2D tickShape = new Line2D.Double();
+
+					for (Tick tick : ticks) {
+						// Draw tick
+						if ((tick.position == null)
+								|| (tick.normal == null)) {
+							continue;
+						}
+						Point2D tickPoint = tick.position.getPoint2D();
+						Point2D tickNormal = tick.normal.getPoint2D();
+
+						double tickLength1;
+						double tickAlignment1;
+						Paint tickPaint;
+						Stroke tickStroke1;
+						if (TickType.MINOR.equals(tick.type)) {
+							tickLength1 = renderer.getTickMinorLengthAbsolute();
+							tickAlignment1 = renderer.getMinorTickAlignment();
+							tickPaint = renderer.getMinorTickColor();
+							tickStroke1 = renderer.getMinorTickStroke();
+						} else {
+							tickLength1 = getTickLengthAbsolute();
+							tickAlignment1 = renderer.getTickAlignment();
+							tickPaint =
+								renderer.getTickColor();
+							tickStroke1 = renderer.getTickStroke();
+						}
+
+						double tickLengthInner = tickLength1*tickAlignment1;
+						double tickLengthOuter = tickLength1*(1.0 - tickAlignment1);
+
+						if ((drawTicksMajor && (tick.type == TickType.MAJOR) ||
+								tick.type == TickType.CUSTOM) || (drawTicksMinor &&
+								tick.type == TickType.MINOR)) {
+							tickShape.setLine(
+								tickPoint.getX() - tickNormal.getX()*tickLengthInner,
+								tickPoint.getY() - tickNormal.getY()*tickLengthInner,
+								tickPoint.getX() + tickNormal.getX()*tickLengthOuter,
+								tickPoint.getY() + tickNormal.getY()*tickLengthOuter
+							);
+							GraphicsUtils.drawPaintedShape(
+									graphics, tickShape, tickPaint, null, tickStroke1);
+						}
+
+						// Draw label
+						if (isTickLabelVisible && (tick.type == TickType.MAJOR ||
+								tick.type == TickType.CUSTOM)) {
+							String tickLabelText = tick.label;
+							if (tickLabelText != null && !tickLabelText.trim().isEmpty()) {
+								Label tickLabel = new Label(tickLabelText);
+								tickLabel.setFont(renderer.getTickFont());
+								// TODO Allow separate colors for ticks and tick labels?
+								tickLabel.setColor(tickPaint);
+								double labelDist = tickLengthOuter + tickLabelDist;
+								layoutLabel(tickLabel, tickPoint, tickNormal,
+										labelDist, isTickLabelOutside, tickLabelRotation1);
+								tickLabel.draw(context);
+							}
+						}
+					}
+				}
+
+				// Draw axis label
+				Label axisLabel = renderer.getLabel();
+				if (axisLabel != null && !axisLabel.getText().trim().isEmpty()) {
+					double tickLength1 = getTickLengthAbsolute();
+					double tickAlignment1 = renderer.getTickAlignment();
+					double tickLengthOuter = tickLength1*(1.0 - tickAlignment1);
+					double tickLabelDistance1 = renderer.getTickLabelDistanceAbsolute();
+
+					double labelDistance1 = renderer.getLabelDistance()*fontSize;
+					double labelDist =
+						tickLengthOuter + tickLabelDistance1 + fontSize + labelDistance1;
+					double axisLabelPos =
+						(axis.getMin().doubleValue() + axis.getMax().doubleValue()) * 0.5;
+					boolean isTickLabelOutside = renderer.isTickLabelsOutside();
+
+					PointND<Double> labelPos = getPosition(axis, axisLabelPos, false, true);
+					PointND<Double> labelNormal = getNormal(axis, axisLabelPos, false, true);
+
+					if (labelPos != null && labelNormal != null) {
+						layoutLabel(axisLabel, labelPos.getPoint2D(),
+								labelNormal.getPoint2D(), labelDist,
+								isTickLabelOutside, axisLabel.getRotation());
+						axisLabel.draw(context);
+					}
+				}
+
+				graphics.setPaint(paintOld);
+				graphics.setStroke(strokeOld);
+				graphics.setTransform(txOrig);
+			}
+
+			private void layoutLabel(Label label1, Point2D labelPos, Point2D labelNormal,
+									 double labelDist, boolean isLabelOutside, double rotation) {
+				Rectangle2D labelSize = label1.getTextRectangle();
+				Shape marginShape = new Rectangle2D.Double(
+					0, 0,
+					labelSize.getWidth() + 2.0*labelDist, labelSize.getHeight() + 2.0*labelDist
+				);
+				Rectangle2D marginBounds = marginShape.getBounds2D();
+				label1.setRotation(rotation);
+				if ((rotation%360.0) != 0.0) {
+					marginShape = AffineTransform.getRotateInstance(
+						Math.toRadians(-rotation),
+						marginBounds.getCenterX(),
+						marginBounds.getCenterY()
+					).createTransformedShape(marginShape);
+				}
+				marginBounds = marginShape.getBounds2D();
+
+				double intersRayLength = marginBounds.getHeight()*marginBounds.getHeight() +
+					marginBounds.getWidth()*marginBounds.getWidth();
+				double intersRayDir = (isLabelOutside?-1.0:1.0)*intersRayLength;
+				List<Point2D> descriptionBoundsIntersections = GeometryUtils.intersection(
+					marginBounds,
+					new Line2D.Double(
+						marginBounds.getCenterX(),
+						marginBounds.getCenterY(),
+						marginBounds.getCenterX() + intersRayDir*labelNormal.getX(),
+						marginBounds.getCenterY() + intersRayDir*labelNormal.getY()
+					)
+				);
+				if (!descriptionBoundsIntersections.isEmpty()) {
+					Point2D inters = descriptionBoundsIntersections.get(0);
+					double intersX = inters.getX() - marginBounds.getCenterX();
+					double intersY = inters.getY() - marginBounds.getCenterY();
+					double posX = labelPos.getX() - intersX - labelSize.getWidth()/2.0;
+					double posY = labelPos.getY() - intersY - labelSize.getHeight()/2.0;
+
+					label1.setBounds(posX, posY, labelSize.getWidth(), labelSize.getHeight());
+				}
+			}
+
+			@Override
+			public Dimension2D getPreferredSize() {
+				AbstractAxisRenderer2D renderer = AbstractAxisRenderer2D.this;
+				double fontSize = renderer.getTickFont().getSize2D();
+				double tickLength1 = getTickLengthAbsolute();
+				double tickAlignment1 = renderer.getTickAlignment();
+				double tickLengthOuter = tickLength1*(1.0 - tickAlignment1);
+				double labelDistance1 = renderer.getTickLabelDistanceAbsolute() + tickLengthOuter;
+				double minSize = fontSize + labelDistance1 + tickLengthOuter;
+				return new org.xbib.graphics.graph.gral.graphics.Dimension2D.Double(minSize, minSize);
+			}
+		};
+	}
+
+	/**
+	 * Returns a list of all tick element on the axis.
+	 * @param axis Axis
+	 * @return A list of {@code Tick} instances
+	 */
+	public List<Tick> getTicks(Axis axis) {
+		List<Tick> ticks = new LinkedList<>();
+
+		if (!axis.isValid()) {
+			return ticks;
+		}
+
+		double min = axis.getMin().doubleValue();
+		double max = axis.getMax().doubleValue();
+
+		Set<Double> tickPositions = new HashSet<>();
+
+		createTicksCustom(ticks, axis, min, max, tickPositions);
+
+		boolean isAutoSpacing = isTicksAutoSpaced();
+		// If the spacing is invalid, use auto spacing
+		if (!isAutoSpacing) {
+			Number tickSpacing = getTickSpacing();
+			if (tickSpacing == null) {
+				isAutoSpacing = true;
+			} else {
+				double tickSpacingValue = tickSpacing.doubleValue();
+				if (tickSpacingValue <= 0.0 || !MathUtils.isCalculatable(tickSpacingValue)) {
+					isAutoSpacing = true;
+				}
+			}
+		}
+
+		createTicks(ticks, axis, min, max, tickPositions, isAutoSpacing);
+
+		return ticks;
+	}
+
+	/**
+	 * Returns the absolute length of a major tick.
+	 * @return Major tick length in pixels.
+	 */
+	protected double getTickLengthAbsolute() {
+		double fontSize = getTickFont().getSize2D();
+		return getTickLength()*fontSize;
+	}
+
+	/**
+	 * Returns the absolute length of a minor tick.
+	 * @return Minor tick length in pixels.
+	 */
+	protected double getTickMinorLengthAbsolute() {
+		double fontSize = getTickFont().getSize2D();
+		return getMinorTickLength()*fontSize;
+	}
+
+	/**
+	 * Returns the absolute distance between ticks and labels.
+	 * @return Distance in pixels.
+	 */
+	protected double getTickLabelDistanceAbsolute() {
+		double fontSize = getTickFont().getSize2D();
+		return getTickLabelDistance()*fontSize;
+	}
+
+	/**
+	 * Adds minor and major ticks to a list of ticks.
+	 * @param ticks List of ticks
+	 * @param axis Axis
+	 * @param min Minimum value of axis
+	 * @param max Maximum value of axis
+	 * @param tickPositions Set of tick positions
+	 * @param isAutoSpacing Use automatic scaling
+	 */
+	protected abstract void createTicks(List<Tick> ticks, Axis axis,
+			double min, double max, Set<Double> tickPositions,
+			boolean isAutoSpacing);
+
+	/**
+	 * Adds custom ticks to a list of ticks.
+	 * @param ticks List of ticks
+	 * @param axis Axis
+	 * @param min Minimum value of axis
+	 * @param max Maximum value of axis
+	 * @param tickPositions Set of tick positions
+	 */
+	protected void createTicksCustom(List<Tick> ticks, Axis axis,
+			double min, double max, Set<Double> tickPositions) {
+		Map<? extends Number, String> labelsCustom = getCustomTicks();
+		if (labelsCustom != null) {
+			for (Number tickPositionWorldObj : labelsCustom.keySet()) {
+				double tickPositionWorld = tickPositionWorldObj.doubleValue();
+				if (tickPositionWorld < min || tickPositionWorld > max) {
+					continue;
+				}
+				Tick tick = getTick(
+					TickType.CUSTOM, axis, tickPositionWorld);
+				ticks.add(tick);
+				tickPositions.add(tickPositionWorld);
+			}
+		}
+	}
+
+	/**
+	 * Returns the point of the tick mark (in pixel coordinates) on the
+	 * specified axis with the specified value.
+	 * @param type Type of tick mark.
+	 * @param axis Axis containing the tick mark.
+	 * @param tickPositionWorld Displayed value on the axis.
+	 * @return Object describing the desired tick mark.
+	 */
+	protected Tick getTick(TickType type, Axis axis, double tickPositionWorld) {
+		// Calculate position of tick on axis shape
+		PointND<Double> tickPoint = getPosition(axis, tickPositionWorld, false, false);
+
+		// Calculate tick normal
+		PointND<Double> tickNormal = getNormal(axis, tickPositionWorld, false, false);
+
+		// Retrieve tick label
+		String tickLabel;
+		Map<Double, String> labelsCustom = getCustomTicks();
+		if (labelsCustom != null && labelsCustom.containsKey(tickPositionWorld)) {
+			tickLabel = labelsCustom.get(tickPositionWorld);
+		} else {
+			Format labelFormat = getTickLabelFormat();
+			if (labelFormat != null) {
+				tickLabel = labelFormat.format(tickPositionWorld);
+			} else {
+				tickLabel = String.valueOf(tickPositionWorld);
+			}
+		}
+
+		return new Tick(type, tickPoint, tickNormal, null, null, tickLabel);
+	}
+
+	/**
+	 * Returns the normal vector at the position of the specified value.
+	 * The vector is normalized.
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @param forceLinear Force linear interpolation.
+	 * @return N-dimensional normal vector at the position
+	 */
+	public PointND<Double> getNormal(Axis axis, Number value,
+			boolean extrapolate, boolean forceLinear) {
+		double valueView;
+		if (forceLinear) {
+			valueView = (value.doubleValue() - axis.getMin().doubleValue()) /
+				axis.getRange()*getShapeLength();
+		} else {
+			valueView = worldToView(axis, value, extrapolate);
+		}
+
+		int segmentIndex = MathUtils.binarySearchFloor(shapeSegmentLengthsAccumulated, valueView);
+		if (segmentIndex < 0 || segmentIndex >= shapeLines.length) {
+			return null;
+		}
+
+		segmentIndex = MathUtils.limit(
+				segmentIndex, 0, shapeLineNormals.length - 1);
+		boolean normalOrientationClockwise = AbstractAxisRenderer2D.this
+			.isShapeNormalOrientationClockwise();
+		double normalOrientation =
+				normalOrientationClockwise ? 1.0 : -1.0;
+
+		return new PointND<>(
+				normalOrientation*shapeLineNormals[segmentIndex].getX(),
+				normalOrientation*shapeLineNormals[segmentIndex].getY()
+		);
+	}
+
+	/**
+	 * Returns the length of the shape path which is used to render axes.
+	 * @return Shape length.
+	 */
+	protected double getShapeLength() {
+		if (shapeSegmentLengthsAccumulated == null || shapeSegmentLengthsAccumulated.length == 0) {
+			return 0.0;
+		}
+		return shapeSegmentLengthsAccumulated[shapeSegmentLengthsAccumulated.length - 1];
+	}
+
+	/**
+	 * Returns the position of the specified value on the axis.
+	 * The value is returned in view coordinates.
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @param forceLinear Force linear interpolation.
+	 * @return N-dimensional point of the value
+	 */
+	public PointND<Double> getPosition(Axis axis, Number value,
+			boolean extrapolate, boolean forceLinear) {
+		if (shapeLines == null || shapeLines.length == 0 || value == null) {
+			return null;
+		}
+
+		// Determine relative position of the value
+		double relativePositionOnShapePath = axis.getPosition(value).doubleValue();
+		if (!extrapolate) {
+			relativePositionOnShapePath = MathUtils.limit(relativePositionOnShapePath, 0.0, 1.0);
+		}
+
+		// Determine absolute position of the value
+		double positionOnShapePath;
+		if (forceLinear) {
+			positionOnShapePath = relativePositionOnShapePath*getShapeLength();
+		} else {
+			positionOnShapePath = worldToView(axis, value, extrapolate);
+		}
+
+		if (Double.isNaN(positionOnShapePath)) {
+			return null;
+		}
+
+		// TODO Check if this is a valid way to allow infinite values
+		if (positionOnShapePath == Double.NEGATIVE_INFINITY) {
+			positionOnShapePath = 0.0;
+		} else if (positionOnShapePath == Double.POSITIVE_INFINITY) {
+			positionOnShapePath = 1.0;
+		}
+
+		// Determine shape segment
+		int segmentIndex;
+		if (relativePositionOnShapePath <= 0.0) {
+				segmentIndex = 0;
+		} else if (relativePositionOnShapePath >= 1.0) {
+				segmentIndex = shapeLines.length - 1;
+		} else {
+			// Determine to which segment the value belongs using a binary search
+			segmentIndex = MathUtils.binarySearchFloor(shapeSegmentLengthsAccumulated, positionOnShapePath);
+		}
+
+		if (segmentIndex < 0 || segmentIndex >= shapeLines.length) {
+			return null;
+		}
+
+		// Compute actual position of the value in view coordinates
+		Line2D segment = shapeLines[segmentIndex];
+		double segmentLen = shapeSegmentLengths[segmentIndex];
+		double segmentLenAcc = shapeSegmentLengthsAccumulated[segmentIndex];
+		double relLen = (positionOnShapePath - segmentLenAcc)/segmentLen;
+		double x = segment.getX1() + (segment.getX2() - segment.getX1())*relLen;
+		double y = segment.getY1() + (segment.getY2() - segment.getY1())*relLen;
+		return new PointND<>(x, y);
+	}
+
+	/**
+	 * Calculates important aspects of the specified shape.
+	 * @param shape Shape to be evaluated.
+	 */
+	protected final void evaluateShape(Shape shape) {
+		boolean directionSwapped = isShapeDirectionSwapped();
+		shapeLines = GeometryUtils.shapeToLines(shape, directionSwapped);
+		shapeSegmentLengths = new double[shapeLines.length];
+		// First length is always 0.0, last length is the total length
+		shapeSegmentLengthsAccumulated = new double[shapeLines.length + 1];
+		shapeLineNormals = new Point2D[shapeLines.length];
+
+		if (shapeLines.length == 0) {
+			return;
+		}
+
+		for (int i = 0; i < shapeLines.length; i++) {
+			Line2D line = shapeLines[i];
+
+			// Calculate length of axis shape at each shape segment
+			double segmentLength = line.getP1().distance(line.getP2());
+			shapeSegmentLengths[i] = segmentLength;
+			shapeSegmentLengthsAccumulated[i + 1] = shapeSegmentLengthsAccumulated[i] + segmentLength;
+
+			// Calculate a normalized vector perpendicular to the current
+			// axis shape segment
+			shapeLineNormals[i] = new Point2D.Double(
+				 (line.getY2() - line.getY1()) / segmentLength,
+				-(line.getX2() - line.getX1()) / segmentLength
+			);
+		}
+	}
+
+	@Override
+	public Number getIntersection() {
+		return intersection;
+	}
+
+	@Override
+	public void setIntersection(Number intersection) {
+		this.intersection = intersection;
+	}
+
+	@Override
+	public Shape getShape() {
+		return shape;
+	}
+
+	@Override
+	public void setShape(Shape shape) {
+		this.shape = shape;
+		evaluateShape(shape);
+	}
+
+	@Override
+	public boolean isShapeVisible() {
+		return shapeVisible;
+	}
+
+	@Override
+	public void setShapeVisible(boolean shapeVisible) {
+		this.shapeVisible = shapeVisible;
+	}
+
+	@Override
+	public boolean isShapeNormalOrientationClockwise() {
+		return shapeNormalOrientationClockwise;
+	}
+
+	@Override
+	public void setShapeNormalOrientationClockwise(boolean clockwise) {
+		this.shapeNormalOrientationClockwise = clockwise;
+	}
+
+	@Override
+	public Paint getShapeColor() {
+		return shapeColor;
+	}
+
+	@Override
+	public void setShapeColor(Paint color) {
+		this.shapeColor = color;
+	}
+
+	@Override
+	public Stroke getShapeStroke() {
+		return shapeStroke;
+	}
+
+	@Override
+	public void setShapeStroke(Stroke stroke) {
+		this.shapeStroke = stroke;
+	}
+
+	@Override
+	public boolean isShapeDirectionSwapped() {
+		return shapeDirectionSwapped;
+	}
+
+	@Override
+	public void setShapeDirectionSwapped(boolean directionSwapped) {
+		this.shapeDirectionSwapped = directionSwapped;
+	}
+
+	@Override
+	public boolean isTicksVisible() {
+		return ticksVisible;
+	}
+
+	@Override
+	public void setTicksVisible(boolean ticksVisible) {
+		this.ticksVisible = ticksVisible;
+	}
+
+	@Override
+	public Number getTickSpacing() {
+		return tickSpacing;
+	}
+
+	@Override
+	public void setTickSpacing(Number spacing) {
+		this.tickSpacing = spacing;
+	}
+
+	@Override
+	public boolean isTicksAutoSpaced() {
+		return ticksAutoSpaced;
+	}
+
+	@Override
+	public void setTicksAutoSpaced(boolean autoSpaced) {
+		this.ticksAutoSpaced = autoSpaced;
+	}
+
+	@Override
+	public double getTickLength() {
+		return tickLength;
+	}
+
+	@Override
+	public void setTickLength(double length) {
+		this.tickLength = length;
+	}
+
+	@Override
+	public Stroke getTickStroke() {
+		return tickStroke;
+	}
+
+	@Override
+	public void setTickStroke(Stroke stroke) {
+		this.tickStroke = stroke;
+	}
+
+	@Override
+	public double getTickAlignment() {
+		return tickAlignment;
+	}
+
+	@Override
+	public void setTickAlignment(double alignment) {
+		this.tickAlignment = alignment;
+	}
+
+	@Override
+	public Font getTickFont() {
+		return tickFont;
+	}
+
+	@Override
+	public void setTickFont(Font font) {
+		this.tickFont = font;
+	}
+
+	@Override
+	public Paint getTickColor() {
+		return tickColor;
+	}
+
+	@Override
+	public void setTickColor(Paint color) {
+		this.tickColor = color;
+	}
+
+	@Override
+	public boolean isTickLabelsVisible() {
+		return tickLabelsVisible;
+	}
+
+	@Override
+	public void setTickLabelsVisible(boolean tickLabelsVisible) {
+		this.tickLabelsVisible = tickLabelsVisible;
+	}
+
+	@Override
+	public Format getTickLabelFormat() {
+		return tickLabelFormat;
+	}
+
+	@Override
+	public void setTickLabelFormat(Format format) {
+		this.tickLabelFormat = format;
+	}
+
+	@Override
+	public double getTickLabelDistance() {
+		return tickLabelDistance;
+	}
+
+	@Override
+	public void setTickLabelDistance(double distance) {
+		this.tickLabelDistance = distance;
+	}
+
+	@Override
+	public boolean isTickLabelsOutside() {
+		return tickLabelsOutside;
+	}
+
+	@Override
+	public void setTickLabelsOutside(boolean labelsOutside) {
+		this.tickLabelsOutside = labelsOutside;
+	}
+
+	@Override
+	public double getTickLabelRotation() {
+		return tickLabelRotation;
+	}
+
+	@Override
+	public void setTickLabelRotation(double angle) {
+		this.tickLabelRotation = angle;
+	}
+
+	@Override
+	public boolean isMinorTicksVisible() {
+		return minorTickVisible;
+	}
+
+	@Override
+	public void setMinorTicksVisible(boolean minorTicksVisible) {
+		this.minorTickVisible = minorTicksVisible;
+	}
+
+	@Override
+	public int getMinorTicksCount() {
+		return minorTicksCount;
+	}
+
+	@Override
+	public void setMinorTicksCount(int count) {
+		this.minorTicksCount = count;
+	}
+
+	@Override
+	public double getMinorTickLength() {
+		return minorTickLength;
+	}
+
+	@Override
+	public void setMinorTickLength(double length) {
+		this.minorTickLength = length;
+	}
+
+	@Override
+	public Stroke getMinorTickStroke() {
+		return minorTickStroke;
+	}
+
+	@Override
+	public void setMinorTickStroke(Stroke stroke) {
+		this.minorTickStroke = stroke;
+	}
+
+	@Override
+	public double getMinorTickAlignment() {
+		return minorTickAlignment;
+	}
+
+	@Override
+	public void setMinorTickAlignment(double alignment) {
+		this.minorTickAlignment = alignment;
+	}
+
+	@Override
+	public Paint getMinorTickColor() {
+		return minorTickColor;
+	}
+
+	@Override
+	public void setMinorTickColor(Paint color) {
+		this.minorTickColor = color;
+	}
+
+	@Override
+	public Map<Double, String> getCustomTicks() {
+		return Collections.unmodifiableMap(customTicks);
+	}
+
+	@Override
+	public void setCustomTicks(Map<Double, String> positionsAndLabels) {
+		customTicks.clear();
+		customTicks.putAll(positionsAndLabels);
+	}
+
+	@Override
+	public Label getLabel() {
+		return label;
+	}
+
+	@Override
+	public void setLabel(Label label) {
+		this.label = label;
+	}
+
+	@Override
+	public double getLabelDistance() {
+		return labelDistance;
+	}
+
+	@Override
+	public void setLabelDistance(double distance) {
+		this.labelDistance = distance;
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/axes/Axis.java

@@ -0,0 +1,185 @@
+package org.xbib.graphics.graph.gral.plots.axes;
+
+import java.io.IOException;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+/**
+ * <p>Class that represents an arbitrary axis.</p>
+ * <p>Functionality includes:</p>
+ * <ul>
+ *   <li>Different ways of setting and getting the range of this axis</li>
+ *   <li>Administration of {@link AxisListener AxisListeners}</li>
+ * </ul>
+ */
+public class Axis {
+
+	/** Objects that will be notified when axis settings are changing. */
+	private transient Set<AxisListener> axisListeners;
+
+	/** Minimal value on axis. */
+	private Number min;
+	/** Maximal value on axis. */
+	private Number max;
+	/** Has the axis a valid range. Used for auto-scaling. */
+	private boolean autoscaled;
+
+	/**
+	 * Initializes a new instance with a specified automatic scaling mode, but
+	 * without minimum and maximum values.
+	 * @param autoscaled {@code true} to turn automatic scaling on
+	 */
+	private Axis(boolean autoscaled) {
+		axisListeners = new HashSet<>();
+		this.autoscaled = autoscaled;
+	}
+
+	/**
+	 * Initializes a new instance without minimum and maximum values.
+	 */
+	public Axis() {
+		this(true);
+	}
+
+	/**
+	 * Initializes a new instance with the specified minimum and maximum values.
+	 * @param min minimum value
+	 * @param max maximum value
+	 */
+	public Axis(Number min, Number max) {
+		this(false);
+		this.min = min;
+		this.max = max;
+	}
+
+	/**
+	 * Adds the specified {@code AxisListener} to this Axis.
+	 * The Listeners will be notified if changes to the Axis occur,
+	 * for Example if the minimum or maximum value changes.
+	 * @param listener Listener to be added
+	 * @see AxisListener
+	 */
+	public void addAxisListener(AxisListener listener) {
+		axisListeners.add(listener);
+	}
+
+	/**
+	 * Removes the specified {@code AxisListener} from this Axis.
+	 * @param listener Listener to be removed
+	 * @see AxisListener
+	 */
+	public void removeAxisListener(AxisListener listener) {
+		axisListeners.remove(listener);
+	}
+
+	/**
+	 * Notifies all registered {@code AxisListener}s that the value
+	 * range has changed.
+	 * @param min new minimum value
+	 * @param max new maximum value
+	 */
+	private void fireRangeChanged(Number min, Number max) {
+		for (AxisListener listener : axisListeners) {
+			listener.rangeChanged(this, min, max);
+		}
+	}
+
+	/**
+	 * Returns the minimum value to be displayed.
+	 * @return Minimum value.
+	 */
+	public Number getMin() {
+		return min;
+	}
+
+	/**
+	 * Sets the minimum value to be displayed.
+	 * @param min Minimum value.
+	 */
+	public void setMin(Number min) {
+		setRange(min, getMax());
+	}
+
+	/**
+	 * Returns the maximum value to be displayed.
+	 * @return Maximum value.
+	 */
+	public Number getMax() {
+		return max;
+	}
+
+	/**
+	 * Sets the maximum value to be displayed.
+	 * @param max Maximum value.
+	 */
+	public void setMax(Number max) {
+		setRange(getMin(), max);
+	}
+
+	/**
+	 * Returns the range of values to be displayed.
+	 * @return Distance between maximum and minimum value.
+	 */
+	public double getRange() {
+		return getMax().doubleValue() - getMin().doubleValue();
+	}
+
+	/**
+	 * Sets the range of values to be displayed.
+	 * @param min Minimum value.
+	 * @param max Maximum value.
+	 */
+	public void setRange(Number min, Number max) {
+		if ((getMin() != null) && getMin().equals(min) &&
+				(getMax() != null) && getMax().equals(max)) {
+			return;
+		}
+		this.min = min;
+		this.max = max;
+		fireRangeChanged(min, max);
+	}
+
+	/**
+	 * Returns the relative position of the specified value on the axis.
+	 * The value is returned in view coordinates.
+	 * @param value Value whose position is to be determined
+	 * @return Position relative to axis range
+	 */
+	public Number getPosition(Number value) {
+		if (value == null) {
+			return null;
+		}
+		return (value.doubleValue() - getMin().doubleValue()) /
+				getRange();
+	}
+
+	/**
+	 * Returns whether the axis range should be determined automatically rather
+	 * than using the axis's minimum and a maximum values.
+	 * @return whether the axis is scaled automatically to fit the current data
+	 */
+	public boolean isAutoscaled() {
+		return autoscaled;
+	}
+
+	/**
+	 * Sets whether the axis range should be determined automatically rather
+	 * than using the axis's minimum and a maximum values.
+	 * @param autoscaled Defines whether the axis should be automatically
+	 *                   scaled to fit the current data.
+	 */
+	public void setAutoscaled(boolean autoscaled) {
+		this.autoscaled = autoscaled;
+	}
+
+	/**
+	 * Returns whether the currently set minimum and maximum values are valid.
+	 * @return {@code true} when minimum and maximum values are correct,
+	 *         otherwise {@code false}
+	 */
+	public boolean isValid() {
+		return MathUtils.isCalculatable(min) && MathUtils.isCalculatable(max);
+	}
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/axes/AxisListener.java

@@ -0,0 +1,14 @@
+package org.xbib.graphics.graph.gral.plots.axes;
+
+/**
+ * Interface that provides a function to listen for changes in axes.
+ */
+public interface AxisListener {
+	/**
+	 * Notified if the range of the axis has changed.
+	 * @param axis Axis instance that has changed.
+	 * @param min New minimum value.
+	 * @param max New maximum value.
+	 */
+	void rangeChanged(Axis axis, Number min, Number max);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/axes/AxisRenderer.java

@@ -0,0 +1,453 @@
+package org.xbib.graphics.graph.gral.plots.axes;
+
+import java.awt.Font;
+import java.awt.Paint;
+import java.awt.Shape;
+import java.awt.Stroke;
+import java.text.Format;
+import java.util.List;
+import java.util.Map;
+
+import org.xbib.graphics.graph.gral.graphics.Drawable;
+import org.xbib.graphics.graph.gral.graphics.Label;
+import org.xbib.graphics.graph.gral.util.PointND;
+
+/**
+ * Interface for generic renderers of axes.
+ */
+public interface AxisRenderer {
+	/**
+	 * Returns a component that displays the specified axis.
+	 * @param axis axis to be displayed
+	 * @return component displaying the axis
+	 * @see Axis
+	 */
+	Drawable getRendererComponent(Axis axis);
+
+	/*
+	 * TODO: Enforce minimum and maximum values when extrapolation is turned off
+	 * by using MathUtils.limit(double, double, double) on the result
+	 */
+	/**
+	 * Converts a world (axis) coordinate value to a view (screen) coordinate
+	 * value. If @code{extrapolate == false}, this method should return 0.0 when
+	 * value is smaller than @code{axis.getMin()} and {@code getShapeLength()} when
+	 * value is larger than @code{axis.getMax(}).
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @return Screen coordinate value
+	 */
+	double worldToView(Axis axis, Number value,
+					   boolean extrapolate);
+
+	/**
+	 * Converts a view (screen) coordinate value to a world (axis) coordinate
+	 * value.
+	 * @param axis Axis
+	 * @param value View coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @return World coordinate value
+	 */
+	Number viewToWorld(Axis axis, double value,
+					   boolean extrapolate);
+
+	/**
+	 * Returns a list of all tick element on the axis.
+	 * @param axis Axis
+	 * @return A list of {@code Tick} instances
+	 */
+	List<Tick> getTicks(Axis axis);
+
+	/**
+	 * Returns the position of the specified value on the axis.
+	 * The value is returned in view coordinates.
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @param forceLinear Force linear interpolation.
+	 * @return N-dimensional point of the value
+	 */
+	PointND<Double> getPosition(Axis axis, Number value, boolean extrapolate, boolean forceLinear);
+
+	/**
+	 * Returns the normal vector at the position of the specified value.
+	 * The vector is normalized.
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @param forceLinear Force linear interpolation.
+	 * @return N-dimensional normal vector at the position
+	 */
+	PointND<Double> getNormal(Axis axis, Number value, boolean extrapolate, boolean forceLinear);
+
+	/**
+	 * Returns the intersection point of the axis.
+	 * @return Point at which this axis intersects other axes.
+	 */
+	Number getIntersection();
+
+	/**
+	 * Sets the intersection point of the axis.
+	 * @param intersection Point at which this axis intersects other axes.
+	 */
+	void setIntersection(Number intersection);
+
+	/**
+	 * Returns the shape of the axis.
+	 * @return Shape used for drawing.
+	 */
+	Shape getShape();
+
+	/**
+	 * Sets the shape of the axis.
+	 * @param shape Shape used for drawing.
+	 */
+	void setShape(Shape shape);
+
+	/**
+	 * Returns whether the shape of the axis will be drawn.
+	 * This doesn't influence ticks or labels.
+	 * @return {@code true} if the shape should be drawn, false otherwise.
+	 */
+	boolean isShapeVisible();
+
+	/**
+	 * Sets whether the shape of the axis will be drawn.
+	 * This doesn't influence ticks or labels.
+	 * @param shapeVisible {@code true} if the shape should be drawn, false otherwise.
+	 */
+	void setShapeVisible(boolean shapeVisible);
+
+	/**
+	 * Returns whether the normal vector of the shape is calculated using
+	 * clockwise or counterclockwise rotation.
+	 * @return {@code true} if the orientation is clockwise, {@code false} if it is
+	 * counterclockwise.
+	 */
+	boolean isShapeNormalOrientationClockwise();
+
+	/**
+	 * Sets whether the normal vector of the shape is calculated using
+	 * clockwise or counterclockwise rotation.
+	 * @param clockwise {@code true} if the orientation is clockwise,
+	 * {@code false} if it is counterclockwise.
+	 */
+	void setShapeNormalOrientationClockwise(boolean clockwise);
+
+	/**
+	 * Returns the paint used to draw the axis, its ticks and its labels.
+	 * @return Paint used for drawing.
+	 */
+	Paint getShapeColor();
+
+	/**
+	 * Sets the paint used to draw the axis, its ticks and its labels.
+	 * @param color Paint used for drawing.
+	 */
+	void setShapeColor(Paint color);
+
+	/**
+	 * Returns the stroke which defines the shape of the axis.
+	 * @return Stroke used for drawing the shape.
+	 */
+	Stroke getShapeStroke();
+
+	/**
+	 * Sets the stroke which defines the shape of the axis.
+	 * @param stroke Stroke used for drawing the shape.
+	 */
+	void setShapeStroke(Stroke stroke);
+
+	/**
+	 * Returns whether the axis direction is changed.
+	 * @return {@code true} if the shape of the axis is inverted,
+	 * {@code false} otherwise.
+	 */
+	boolean isShapeDirectionSwapped();
+
+	/**
+	 * Sets whether the axis direction will be changed.
+	 * @param directionSwapped {@code true} if the shape of the axis
+	 * should be inverted, {@code false} otherwise.
+	 */
+	void setShapeDirectionSwapped(boolean directionSwapped);
+
+	/**
+	 * Returns whether major ticks are drawn.
+	 * @return {@code true} if major ticks are drawn, {@code false} otherwise.
+	 */
+	boolean isTicksVisible();
+
+	/**
+	 * Sets whether major ticks will be drawn.
+	 * @param ticksVisible {@code true} if major ticks should be drawn,
+	 * {@code false} otherwise.
+	 */
+	void setTicksVisible(boolean ticksVisible);
+
+	/**
+	 * Returns the interval for major ticks.
+	 * @return Distance on axis in which major ticks are drawn.
+	 */
+	Number getTickSpacing();
+
+	/**
+	 * Sets the interval for major ticks.
+	 * @param spacing Distance on axis in which major ticks are drawn.
+	 */
+	void setTickSpacing(Number spacing);
+
+	/**
+	 * Returns whether the interval for major and minor ticks is chosen automatically.
+	 * @return {@code true} if auto-spacing is enabled, {@code false} otherwise.
+	 */
+	boolean isTicksAutoSpaced();
+
+	/**
+	 * Sets whether the interval for major and minor ticks is chosen automatically.
+	 * @param autoSpaced {@code true} if auto-spacing is enabled, {@code false} otherwise.
+	 */
+	void setTicksAutoSpaced(boolean autoSpaced);
+
+	/**
+	 * Returns the length of major tick strokes.
+	 * @return Tick length relative to the font height.
+	 */
+	double getTickLength();
+
+	/**
+	 * Sets the length of major tick strokes.
+	 * @param length Tick length relative to the font height.
+	 */
+	void setTickLength(double length);
+
+	/**
+	 * Returns the stroke which is used to draw all major ticks.
+	 * @return Stroke used for major tick drawing.
+	 */
+	Stroke getTickStroke();
+
+	/**
+	 * Sets the stroke which is used to draw all major ticks.
+	 * @param stroke Stroke used for major tick drawing.
+	 */
+	void setTickStroke(Stroke stroke);
+
+	/**
+	 * Returns the alignment of major ticks relative to the axis.
+	 * 0.0 means outside the plotting area, 0.5 means centered on the axis,
+	 * 1.0 means inside the plotting area.
+	 * @return Major tick alignment relative to the axis.
+	 */
+	double getTickAlignment();
+
+	/**
+	 * Sets the alignment of major ticks relative to the axis.
+	 * 0.0 means outside the plotting area, 0.5 means centered on the axis,
+	 * 1.0 means inside the plotting area.
+	 * @param alignment Major tick alignment relative to the axis.
+	 */
+	void setTickAlignment(double alignment);
+
+	/**
+	 * Returns the font used to display the text of major ticks.
+	 * @return Font used for tick labels.
+	 */
+	Font getTickFont();
+
+	/**
+	 * Sets the font used to display the text of major ticks.
+	 * @param font Font used for tick labels.
+	 */
+	void setTickFont(Font font);
+
+	/**
+	 * Returns the paint used to draw the shapes of major ticks.
+	 * @return Paint used for major tick drawing.
+	 */
+	Paint getTickColor();
+
+	/**
+	 * Sets the paint used to draw the shapes of major ticks.
+	 * @param color Paint used for major tick drawing.
+	 */
+	void setTickColor(Paint color);
+
+	/**
+	 * Returns whether tick labels will be shown.
+	 * @return {@code true} if tick labels will be drawn, {@code false} otherwise.
+	 */
+	boolean isTickLabelsVisible();
+
+	/**
+	 * Sets whether tick labels will be shown.
+	 * @param tickLabelsVisible {@code true} if tick labels will be drawn, {@code false} otherwise.
+	 */
+	void setTickLabelsVisible(boolean tickLabelsVisible);
+
+	/**
+	 * Returns the format which converts the tick values to labels.
+	 * @return Format used for tick labels.
+	 */
+	Format getTickLabelFormat();
+
+	/**
+	 * Sets the format which converts the tick values to labels.
+	 * @param format Format used for tick labels.
+	 */
+	void setTickLabelFormat(Format format);
+
+	/**
+	 * Returns the distance of labels to their ticks.
+	 * @return Label distance relative to the font height.
+	 */
+	double getTickLabelDistance();
+
+	/**
+	 * Sets the distance of labels to their ticks.
+	 * @param distance Label distance relative to the font height.
+	 */
+	void setTickLabelDistance(double distance);
+
+	/**
+	 * Returns whether the tick labels are drawn outside of the plot.
+	 * @return {@code true} if the labels are drawn outside of the plot, {@code false} otherwise.
+	 */
+	boolean isTickLabelsOutside();
+
+	/**
+	 * Sets whether the tick labels are drawn outside of the plot.
+	 * @param tickLabelsOutside {@code true} if the labels are drawn outside of the plot,
+	 * {@code false} otherwise.
+	 */
+	void setTickLabelsOutside(boolean tickLabelsOutside);
+
+	/**
+	 * Returns the rotation of the tick labels.
+	 * @return Tick label rotation in degrees.
+	 */
+	double getTickLabelRotation();
+
+	/**
+	 * Sets the rotation of the tick labels.
+	 * @param angle Tick label rotation in degrees.
+	 */
+	void setTickLabelRotation(double angle);
+
+	/**
+	 * Returns whether minor ticks are drawn.
+	 * @return {@code true} if minor ticks are drawn, {@code false} otherwise.
+	 */
+	boolean isMinorTicksVisible();
+
+	/**
+	 * Sets whether minor ticks are drawn.
+	 * @param minorTicksVisible {@code true} if minor ticks are drawn, {@code false} otherwise.
+	 */
+	void setMinorTicksVisible(boolean minorTicksVisible);
+
+	/**
+	 * Returns the count of minor ticks.
+	 * @return Number of minor ticks between two major ticks.
+	 */
+	int getMinorTicksCount();
+
+	/**
+	 * Sets the count of minor ticks.
+	 * @param count Number of minor ticks between two major ticks.
+	 */
+	void setMinorTicksCount(int count);
+
+	/**
+	 * Returns the length of minor tick strokes.
+	 * @return Tick length relative to font height.
+	 */
+	double getMinorTickLength();
+
+	/**
+	 * Sets the length of minor tick strokes.
+	 * @param length Tick length relative to font height.
+	 */
+	void setMinorTickLength(double length);
+
+	/**
+	 * Returns the stroke used to draw all minor ticks.
+	 * @return Stroke used for minor tick drawing.
+	 */
+	Stroke getMinorTickStroke();
+
+	/**
+	 * Sets the stroke used to draw all minor ticks.
+	 * @param stroke Stroke used for minor tick drawing.
+	 */
+	void setMinorTickStroke(Stroke stroke);
+
+	/**
+	 * Returns the alignment of minor ticks.
+	 * 0.0 means outside the plotting area, 0.5 means centered on the axis,
+	 * 1.0 means inside the plotting area.
+	 * @return Minor tick alignment relative to the axis.
+	 */
+	double getMinorTickAlignment();
+
+	/**
+	 * Sets the alignment of minor ticks.
+	 * 0.0 means outside the plotting area, 0.5 means centered on the axis,
+	 * 1.0 means inside the plotting area.
+	 * @param alignment Minor tick alignment relative to the axis.
+	 */
+	void setMinorTickAlignment(double alignment);
+
+	/**
+	 * Returns the paint used to draw the shapes of minor ticks.
+	 * @return Paint used for minor tick drawing.
+	 */
+	Paint getMinorTickColor();
+
+	/**
+	 * Sets the paint used to draw the shapes of minor ticks.
+	 * @param ticksMinorColor Paint used for minor tick drawing.
+	 */
+	void setMinorTickColor(Paint ticksMinorColor);
+
+	/**
+	 * Returns custom ticks with their respective position and label.
+	 * @return A map of custom tick positions and labels.
+	 */
+	Map<Double, String> getCustomTicks();
+
+	/**
+	 * Sets custom ticks with their respective position and label.
+	 * @param positionsAndLabels A map of custom tick positions and labels.
+	 */
+	void setCustomTicks(Map<Double, String> positionsAndLabels);
+
+	/**
+	 * Returns the label of the axis.
+	 * @return Axis label.
+	 */
+	Label getLabel();
+
+	/**
+	 * Sets the label of the axis.
+	 * @param label Axis label.
+	 */
+	void setLabel(Label label);
+
+	/**
+	 * Returns the distance from the axis to the label.
+	 * @return Distance relative to font height.
+	 */
+	double getLabelDistance();
+
+	/**
+	 * Sets the distance from the axis to the label.
+	 * @param distance Distance relative to font height.
+	 */
+	void setLabelDistance(double distance);
+}

graphics-graph-gral/src/main/java/org/xbib/graphics/graph/gral/plots/axes/LinearRenderer2D.java

@@ -0,0 +1,121 @@
+package org.xbib.graphics.graph.gral.plots.axes;
+
+import java.util.List;
+import java.util.Set;
+
+import org.xbib.graphics.graph.gral.plots.axes.Tick.TickType;
+import org.xbib.graphics.graph.gral.util.MathUtils;
+
+/**
+ * Class that renders axes with a linear scale in two dimensional space.
+ */
+public class LinearRenderer2D extends AbstractAxisRenderer2D {
+
+	/**
+	 * Creates a new renderer for linear axes in two-dimensional space.
+	 */
+	public LinearRenderer2D() {
+	}
+
+	/**
+	 * Converts a world (axis) coordinate value to a view (screen) coordinate
+	 * value.
+	 * @param axis Axis
+	 * @param value World coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @return Screen coordinate value
+	 */
+	public double worldToView(Axis axis, Number value, boolean extrapolate) {
+		double min = axis.getMin().doubleValue();
+		double max = axis.getMax().doubleValue();
+		double val = value.doubleValue();
+		if (!extrapolate) {
+			if (val <= min) {
+				return 0.0;
+			}
+			if (val >= max) {
+				return getShapeLength();
+			}
+		}
+		return (val - min)/(max - min)*getShapeLength();
+	}
+
+	/**
+	 * Converts a view (screen) coordinate value to a world (axis) coordinate
+	 * value.
+	 * @param axis Axis
+	 * @param value View coordinate value to convert
+	 * @param extrapolate Option to activate extrapolation value that are not
+	 *        on the axis
+	 * @return World coordinate value
+	 */
+	public Number viewToWorld(Axis axis, double value, boolean extrapolate) {
+		double min = axis.getMin().doubleValue();
+		double max = axis.getMax().doubleValue();
+		if (!extrapolate) {
+			if (value <= 0.0) {
+				return min;
+			}
+			if (value >= getShapeLength()) {
+				return max;
+			}
+		}
+		return value/getShapeLength()*(max - min) + min;
+	}
+
+	@Override
+	protected void createTicks(List<Tick> ticks, Axis axis, double min,
+			double max, Set<Double> tickPositions, boolean isAutoSpacing) {
+		double tickSpacing = 1.0;
+		int ticksMinorCount = 3;
+		if (isAutoSpacing) {
+			// TODO Use number of screen units to decide whether to subdivide
+			double range = max - min;
+			// 1-steppings (0.1, 1, 10)
+			tickSpacing = MathUtils.magnitude(10.0, range/4.0);
+			// 2-steppings (0.2, 2, 20)
+			if (range/tickSpacing > 8.0) {
+				tickSpacing *= 2.0;
+				ticksMinorCount = 1;
+			}
+			// 5-steppings (0.5, 5, 50)
+			if (range/tickSpacing > 8.0) {
+				tickSpacing *= 2.5;
+				ticksMinorCount = 4;
+			}
+		} else {
+			tickSpacing = getTickSpacing().doubleValue();
+			ticksMinorCount = getMinorTicksCount();
+		}
+
+		double tickSpacingMinor = tickSpacing;
+		if (ticksMinorCount > 0) {
+			tickSpacingMinor = tickSpacing/(ticksMinorCount + 1);
+		}
+
+		double minTickMajor = MathUtils.ceil(min, tickSpacing);
+		double minTickMinor = MathUtils.ceil(min, tickSpacingMinor);
+
+		int ticksTotal = (int) Math.ceil((max - min)/tickSpacingMinor);
+		int initialTicksMinor = (int) ((minTickMajor - min)/tickSpacingMinor);
+
+		// Add major and minor ticks
+		// (Use integer to avoid rounding errors)
+		for (int tickCur = 0; tickCur < ticksTotal; tickCur++) {
+			double tickPositionWorld = minTickMinor + tickCur*tickSpacingMinor;
+			if (tickPositions.contains(tickPositionWorld)) {
+				continue;
+			}
+			TickType tickType = TickType.MINOR;
+			if ((tickCur - initialTicksMinor) % (ticksMinorCount + 1) == 0) {
+				tickType = TickType.MAJOR;
+			}
+			Tick tick = getTick(tickType, axis, tickPositionWorld);
+			if (tick.position != null) {
+				ticks.add(tick);
+				tickPositions.add(tickPositionWorld);
+			}
+		}
+	}
+}