capture a widget image with a GC(转载)

（Form http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet95.java）
capture a widget image with a GC

/*******************************************************************************
 * Copyright (c) 2000, 2004 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;
 
/*
 * GC example snippet: capture a widget image with a GC
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class Snippet95 {

public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setText("Widget");

final Table table = new Table(shell, SWT.MULTI);
table.setLinesVisible(true);
table.setBounds(10, 10, 100, 100);
for (int i = 0; i < 9; i++) {
new TableItem(table, SWT.NONE).setText("item" + i);
}

Button button = new Button(shell, SWT.PUSH);
button.setText("Capture");
button.pack();
button.setLocation(10, 140);
button.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
Point tableSize = table.getSize();
GC gc = new GC(table);
final Image image =
new Image(display, tableSize.x, tableSize.y);
gc.copyArea(image, 0, 0);
gc.dispose();

Shell popup = new Shell(shell);
popup.setText("Image");
popup.addListener(SWT.Close, new Listener() {
public void handleEvent(Event e) {
image.dispose();
}
});

Canvas canvas = new Canvas(popup, SWT.NONE);
canvas.setBounds(10, 10, tableSize.x+10, tableSize.y+10);
canvas.addPaintListener(new PaintListener() {
public void paintControl(PaintEvent e) {
e.gc.drawImage(image, 0, 0);
}
});
popup.pack();
popup.open();
}
});
shell.pack();
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) display.sleep();
}
display.dispose();
}
}