package org.pentaho.reporting.engine.classic.core.modules.output.table.xls.helper;
import java.awt.Color;
import java.util.HashMap;
import java.util.Map;
import org.apache.poi.hssf.usermodel.HSSFPalette;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor;
/**
* Todo: Document me!
* <p/>
* Date: 05.09.2009
* Time: 15:42:53
*
* @author Thomas Morgner.
*/
public class DynamicExcelColorProducer implements ExcelColorProducer
{
private short lastUsedColor = 0x8; // this magic constant stands for first color index in a palette
private HSSFWorkbook workbook;
private Map usedTripplets;
public DynamicExcelColorProducer(final HSSFWorkbook workbook)
{
if (workbook == null)
{
throw new NullPointerException();
}
this.workbook = workbook;
this.usedTripplets = new HashMap();
}
public HSSFColor getColor(final short index)
{
final HSSFPalette palette = workbook.getCustomPalette();
return palette.getColor(index);
}
public short getNearestColor(final Color awtColor)
{
if (lastUsedColor > 64)
{
// we ran out of palette... try to get nearest color then
return StaticExcelColorSupport.getNearestColor(awtColor, usedTripplets);
}
final HSSFPalette palette = workbook.getCustomPalette();
final HSSFColor hssfColor = palette.findColor((byte) awtColor.getRed(),
(byte) awtColor.getGreen(),
(byte) awtColor.getBlue());
if (hssfColor != null && hssfColor.getIndex() < lastUsedColor)
{
return hssfColor.getIndex();
}
else
{
palette.setColorAtIndex(lastUsedColor, (byte) awtColor.getRed(),
(byte) awtColor.getGreen(),
(byte) awtColor.getBlue());
final HSSFColor color = palette.getColor(lastUsedColor);
usedTripplets.put(color.getHexString(), color);
return lastUsedColor++;
}
}
}