/*********************************************************************
 *
 *      Copyright (C) 2006 Andrew Khan
 *
 * This library 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 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package org.xbib.datastructures.xslx.jxl.biff.formula;

/**
 * An error constant
 */
class ErrorConstant extends Operand implements ParsedThing {
    /**
     * The error
     */
    private FormulaErrorCode error;

    /**
     * Constructor
     */
    public ErrorConstant() {
    }

    /**
     * Constructor
     *
     * @param s the error constant
     */
    public ErrorConstant(String s) {
        error = FormulaErrorCode.getErrorCode(s);
    }

    /**
     * Reads the ptg data from the array starting at the specified position
     *
     * @param data the RPN array
     * @param pos  the current position in the array, excluding the ptg identifier
     * @return the number of bytes read
     */
    public int read(byte[] data, int pos) {
        int code = data[pos];
        error = FormulaErrorCode.getErrorCode(code);
        return 1;
    }

    /**
     * Gets the token representation of this item in RPN
     *
     * @return the bytes applicable to this formula
     */
    byte[] getBytes() {
        byte[] data = new byte[2];
        data[0] = Token.ERR.getCode();
        data[1] = (byte) error.getCode();

        return data;
    }

    /**
     * Abstract method implementation to get the string equivalent of this
     * token
     *
     * @param buf the string to append to
     */
    public void getString(StringBuffer buf) {
        buf.append(error.getDescription());
    }

    /**
     * If this formula was on an imported sheet, check that
     * cell references to another sheet are warned appropriately
     * Does nothing
     */
    void handleImportedCellReferences() {
    }
}
