/*******************************************************************************
* Copyright (c) 2012, 2013 Original authors and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Original authors and others - initial API and implementation
******************************************************************************/
package org.eclipse.nebula.widgets.nattable.painter.cell;
import java.util.List;
import org.eclipse.nebula.widgets.nattable.config.IConfigRegistry;
import org.eclipse.nebula.widgets.nattable.layer.cell.ILayerCell;
import org.eclipse.nebula.widgets.nattable.style.CellStyleAttributes;
import org.eclipse.nebula.widgets.nattable.style.CellStyleProxy;
import org.eclipse.nebula.widgets.nattable.style.CellStyleUtil;
import org.eclipse.nebula.widgets.nattable.style.DisplayMode;
import org.eclipse.nebula.widgets.nattable.style.IStyle;
import org.eclipse.nebula.widgets.nattable.util.GUIHelper;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
/**
* <p>
* A cell painter that can blend multiple background colours together when more
* than one has been registered for a given cell.
* </p>
* <p>
* For example, if using the alternating row colour style, when multiple rows
* are selected, with a normal painter, a single selection colour is applied to
* all the selected cell's backgrounds.
* </p>
* <p>
* With this painter, the selection background colour blends with the
* alternating colour rather than just replacing it leaving two alternating
* selection colours.
* </p>
*
* @author Stefan Bolton
*
*/
public class BlendedBackgroundPainter extends TextPainter {
// We wont blend colours with the background colour of the grid. Otherwise,
// if the
// grid's background colour was white, for exmaple, this would result in all
// background colours becoming paler than intended.
private final RGB gridBackgroundColour;
public BlendedBackgroundPainter(final RGB gridBackgroundColour) {
this.gridBackgroundColour = gridBackgroundColour;
}
@Override
protected Color getBackgroundColour(final ILayerCell cell,
final IConfigRegistry configRegistry) {
return blendBackgroundColour(cell, configRegistry,
this.gridBackgroundColour);
}
/**
* Returns a background colour for the specified cell. If multiple colours
* have been registered, they are all blended together.
*
* @param cell
* the
* {@link org.eclipse.nebula.widgets.nattable.layer.cell.LayerCell}
* to get a background colour for.
* @param configRegistry
* an
* {@link org.eclipse.nebula.widgets.nattable.config.IConfigRegistry}
* .
* @param baseColor
* Colours are not blended with this colour.
* @return A blended background colour.
*/
public static Color blendBackgroundColour(final ILayerCell cell,
final IConfigRegistry configRegistry, final RGB baseColor) {
// Get all of the background colours registered for the cell in normal
// mode.
final List<Color> colours = CellStyleUtil.getAllBackgroundColors(cell,
configRegistry, DisplayMode.NORMAL);
// If the cell is selected, get it's selected background colour and add
// to the blending mix.
if (cell.getDisplayMode().equals(DisplayMode.SELECT)) {
final IStyle cellStyle = new CellStyleProxy(configRegistry,
DisplayMode.SELECT, cell.getConfigLabels().getLabels());
colours.add(cellStyle
.getAttributeValue(CellStyleAttributes.BACKGROUND_COLOR));
}
if (colours.size() == 0) {
return null;
} else if (colours.size() == 1) {
return colours.get(0);
} else {
RGB rgb = colours.get(0).getRGB();
for (int i = 1; i < colours.size(); i++) {
// Don't blend with the grid background colour.
if (rgb.equals(baseColor)) {
rgb = colours.get(i).getRGB();
} else if (!colours.get(i).getRGB().equals(baseColor)) {
rgb = GUIHelper.blend(rgb, colours.get(i).getRGB());
}
}
return GUIHelper.getColor(rgb);
}
}
}