| /******************************************************************************* |
| * Copyright (c) 2010 IBM Corporation 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: |
| * Research Group Software Construction, |
| * RWTH Aachen University, Germany - initial API and implementation |
| */ |
| package org.eclipse.draw2d; |
| |
| import org.eclipse.swt.graphics.GC; |
| import org.eclipse.swt.graphics.Image; |
| import org.eclipse.swt.graphics.ImageData; |
| import org.eclipse.swt.graphics.PaletteData; |
| import org.eclipse.swt.graphics.RGB; |
| import org.eclipse.swt.widgets.Display; |
| |
| import org.eclipse.draw2d.geometry.PrecisionRectangle; |
| import org.eclipse.draw2d.geometry.Rectangle; |
| |
| /** |
| * A figure used to render a partly transparent copy of an original source |
| * figure. |
| * |
| * This class is pretty much based on a sample, posted within the GEF newsgroup |
| * (http://dev.eclipse.org/newslists/news.eclipse.tools.gef/msg15158.html), |
| * although we decided to not cache the ghost image itself (but only its image |
| * data), so the figure does not have to be disposed (and may thus directly |
| * extend {@link Figure} rather than {@link ImageFigure}). |
| * |
| * @author Alexander Nyssen |
| * @author Philip Ritzkopf |
| * |
| * @since 3.6 |
| */ |
| public class GhostImageFigure extends Figure { |
| |
| private int alpha = -1; |
| private ImageData ghostImageData; |
| |
| /** |
| * The single constructor. |
| * |
| * @param source |
| * The original figure that will be used to render the ghost |
| * image. |
| * @param alpha |
| * The desired transparency value, to be forwarded to |
| * {@link Graphics#setAlpha(int)}. |
| * @param transparency |
| * The RBG value of the color that is to be regarded as |
| * transparent. May be <code>null</code>. |
| */ |
| public GhostImageFigure(final IFigure source, int alpha, RGB transparency) { |
| this.alpha = alpha; |
| |
| Rectangle sourceFigureRelativePrecisionBounds = new PrecisionRectangle( |
| source.getBounds().getCopy()); |
| |
| Image offscreenImage = new Image(Display.getCurrent(), |
| sourceFigureRelativePrecisionBounds.width, |
| sourceFigureRelativePrecisionBounds.height); |
| |
| GC gc = new GC(offscreenImage.getDevice()); |
| SWTGraphics swtGraphics = new SWTGraphics(gc); |
| swtGraphics.translate(-sourceFigureRelativePrecisionBounds.x, |
| -sourceFigureRelativePrecisionBounds.y); |
| source.paint(swtGraphics); |
| |
| ghostImageData = offscreenImage.getImageData(); |
| if (transparency != null) { |
| ghostImageData.transparentPixel = ghostImageData.palette |
| .getPixel(transparency); |
| } |
| |
| offscreenImage.dispose(); |
| swtGraphics.dispose(); |
| gc.dispose(); |
| } |
| |
| /** |
| * @see Figure#paintFigure(Graphics) |
| */ |
| protected void paintFigure(Graphics graphics) { |
| Image feedbackImage = new Image(Display.getCurrent(), ghostImageData); |
| graphics.setAlpha(alpha); |
| graphics.setClip(getBounds().getCopy()); |
| graphics.drawImage(feedbackImage, 0, 0, ghostImageData.width, |
| ghostImageData.height, getBounds().x, getBounds().y, |
| getBounds().width, getBounds().height); |
| feedbackImage.dispose(); |
| } |
| } |