org.eclipse.xwt.tools.ui.designer.core/src/org/eclipse/xwt/tools/ui/designer/core/figures/ImageFigure.java

/*******************************************************************************
 * Copyright (c) 2006, 2010 Soyatec (http://www.soyatec.com) 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:
 *     Soyatec - initial API and implementation
 *******************************************************************************/
package org.eclipse.xwt.tools.ui.designer.core.figures;

/*
 *  $RCSfile: ImageFigure.java,v $
 *  $Revision: 1.3 $  $Date: 2010/06/18 00:15:23 $ 
 */

import org.eclipse.draw2d.Figure;
import org.eclipse.draw2d.Graphics;
import org.eclipse.draw2d.IFigure;
import org.eclipse.draw2d.geometry.Rectangle;
import org.eclipse.swt.graphics.Image;

/**
 * Figure that takes an image and will display it. This figure will not own the image. It is the responsibility of the caller to maintain the image.
 */
public class ImageFigure extends Figure {

	protected Image image;
	protected boolean useParentImageFigure = false;

	{
		setPreferredSize(10, 10);
	}

	/**
	 * Set the image this figure is to use. NOTE: This figure does not own the image. It shares it. The sender still maintains ownership of the image and must dispose of it when necessary.
	 */
	public void setImage(Image newImage) {
		if (image != null && !image.isDisposed() && image == newImage) {
			return;
		}
		if (image != null) {
			image.dispose();
		}
		image = newImage;
		if (image == null) {
			setPreferredSize(10, 10);
		} else {
			org.eclipse.swt.graphics.Rectangle bounds = newImage.getBounds();
			setPreferredSize(bounds.width, bounds.height);
		}
		revalidate();
		repaint(); // In case didn't change size, still need to repaint.
	}

	/**
	 * Return the image currently being used.
	 */
	public Image getImage() {
		return image;
	}

	/**
	 * Set to use the parent's ImageFigure as the image to use. This figure must a child or grandchild of this ImageFigure. It will paint its portion of the image (depending upon its own bounds) of that ImageFigure. This is to allow the borders to be appropriately clipped while still using the one master image.
	 */
	public void setUseParentImageFigure(boolean aBool) {
		if (this.useParentImageFigure == aBool)
			return;
		useParentImageFigure = aBool;
		image = null;
		setPreferredSize(10, 10);
		revalidate();
		repaint(); // In case didn't change size, still need to repaint.
	}

	protected void paintClientArea(Graphics g) {
		Rectangle r = getClientArea();
		if (!r.isEmpty() && image != null && !image.isDisposed()) {
			g.drawImage(image, r.x, r.y);
		} else if (useParentImageFigure) {
			// Get the parent up the chain that has the actual image to use.
			ImageFigure parentImageFigure = null;
			for (IFigure parent = getParent(); parent != null; parent = parent.getParent()) {
				if (parent instanceof ImageFigure && ((ImageFigure) parent).getImage() != null) {
					parentImageFigure = (ImageFigure) parent;
					break;
				}
			}
			if (parentImageFigure != null) {
				Image parentImage = parentImageFigure.getImage();
				if (parentImage != null) {
					Rectangle parentr = parentImageFigure.getClientArea();
					// Need to be careful, could be we could ask for a region outside the parent image too.
					Image pImage = parentImageFigure.getImage();
					org.eclipse.swt.graphics.Rectangle pBounds = pImage.getBounds();
					// So set the parent size to be no larger than the image size so that we won't ask for outside of it.
					// Image bounds always have x/y of 0. And we know that (0,0) of image is the same as (x,y) of parent rectangle,
					// so only need to worry about size.
					parentr.setSize(Math.min(parentr.width, pBounds.width), Math.min(parentr.height, pBounds.height));
					// Need to get the intersection of the client area with the
					// parent's client area in case the parent's boundary is smaller.
					r = r.intersect(parentr);
					g.drawImage(pImage, r.x - parentr.x, r.y - parentr.y, r.width, r.height, r.x, r.y, r.width, r.height);
				}
			}
		}
		super.paintClientArea(g);
	}
}