update to pdfbox 2.0.21, clean up pdfbox graphics io

io-pdfbox/src/test/java/org/xbib/graphics/io/pdfbox/DanglingCaseTest.java

@@ -0,0 +1,68 @@
+package org.xbib.graphics.io.pdfbox;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.PDPageContentStream;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.pdmodel.graphics.form.PDFormXObject;
+import org.apache.pdfbox.util.Matrix;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.awt.Color;
+import java.io.File;
+import java.io.IOException;
+
+public class DanglingCaseTest {
+
+    @Test
+    public void testDanglingGfx() throws IOException {
+        PDDocument document = new PDDocument();
+        PDPage page = new PDPage(PDRectangle.A4);
+        document.addPage(page);
+        PDPageContentStream contentStream = new PDPageContentStream(document, page);
+        PdfBoxGraphics2D pdfBoxGraphics2D = new PdfBoxGraphics2D(document, 400, 400);
+        PdfBoxGraphics2D child = pdfBoxGraphics2D.create(10, 10, 40, 40);
+        child.setColor(Color.RED);
+        child.fillRect(0, 0, 100, 100);
+        PdfBoxGraphics2D child2 = child.create(20, 20, 10, 10);
+        child2.setColor(Color.GREEN);
+        child2.drawOval(0, 0, 5, 5);
+        child.create();
+        pdfBoxGraphics2D.disposeDanglingChildGraphics();
+        pdfBoxGraphics2D.dispose();
+        PDFormXObject appearanceStream = pdfBoxGraphics2D.getXFormObject();
+        Matrix matrix = new Matrix();
+        matrix.translate(0, 20);
+        contentStream.transform(matrix);
+        contentStream.drawForm(appearanceStream);
+        contentStream.close();
+        File file = new File("build/test/dangling_test.pdf");
+        file.getParentFile().mkdirs();
+        document.save(file);
+        document.close();
+    }
+
+    @Test
+    public void testDanglingDisposeException() {
+        Assertions.assertThrows(IllegalStateException.class, () -> {
+            PDDocument document = new PDDocument();
+            PDPage page = new PDPage(PDRectangle.A4);
+            document.addPage(page);
+            PdfBoxGraphics2D pdfBoxGraphics2D = new PdfBoxGraphics2D(document, 400, 400);
+            pdfBoxGraphics2D.create();
+            pdfBoxGraphics2D.dispose();
+        });
+    }
+
+    @Test
+    public void testDanglingDisposeException2() {
+        Assertions.assertThrows(IllegalStateException.class, () -> {
+            PDDocument document = new PDDocument();
+            PDPage page = new PDPage(PDRectangle.A4);
+            document.addPage(page);
+            PdfBoxGraphics2D pdfBoxGraphics2D = new PdfBoxGraphics2D(document, 400, 400);
+            pdfBoxGraphics2D.create().disposeDanglingChildGraphics();
+        });
+    }
+}