/******************************************************************************* * Copyright (c) 2000, 2006 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: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.snippets;/*  * Tree example snippet: Images on the right side of the TreeItem * * For a detailed explanation of this snippet see * http://www.eclipse.org/articles/Article-CustomDrawingTableAndTreeItems/customDraw.htm#_example5 * * For a list of all SWT example snippets see * http://www.eclipse.org/swt/snippets/ *  * @since 3.2 */import org.eclipse.swt.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.widgets.*;public class Snippet220 {		public static void main(String [] args) {	Display display = new Display();	Shell shell = new Shell(display);	shell.setBounds(10, 10, 350, 200);	Image xImage = new Image (display, 16, 16);	GC gc = new GC(xImage);	gc.setForeground(display.getSystemColor(SWT.COLOR_RED));	gc.drawLine(1, 1, 14, 14);	gc.drawLine(1, 14, 14, 1);	gc.drawOval(2, 2, 11, 11);	gc.dispose();	final int IMAGE_MARGIN = 2;	final Tree tree = new Tree(shell, SWT.CHECK);	tree.setBounds(10, 10, 300, 150);	TreeItem item = new TreeItem(tree, SWT.NONE);	item.setText("root item");	for (int i = 0; i < 4; i++) {		TreeItem newItem = new TreeItem(item, SWT.NONE);		newItem.setText("descendent " + i);		if (i % 2 == 0) newItem.setData(xImage);		item.setExpanded(true);		item = newItem;	}	/*	 * NOTE: MeasureItem and PaintItem are called repeatedly.  Therefore it is	 * critical for performance that these methods be as efficient as possible.	 */	tree.addListener(SWT.MeasureItem, new Listener() {		public void handleEvent(Event event) {			TreeItem item = (TreeItem)event.item;			Image trailingImage = (Image)item.getData();			if (trailingImage != null) {				event.width += trailingImage.getBounds().width + IMAGE_MARGIN;			}		}	});	tree.addListener(SWT.PaintItem, new Listener() {		public void handleEvent(Event event) {			TreeItem item = (TreeItem)event.item;			Image trailingImage = (Image)item.getData();			if (trailingImage != null) {				int x = event.x + event.width + IMAGE_MARGIN;				int itemHeight = tree.getItemHeight();				int imageHeight = trailingImage.getBounds().height;				int y = event.y + (itemHeight - imageHeight) / 2;				event.gc.drawImage(trailingImage, x, y);			}		}	});	shell.open();	while (!shell.isDisposed()) {		if (!display.readAndDispatch()) display.sleep();	}	xImage.dispose();	display.dispose();}}