NonRectangularShellFromTransparencyImage.java Source code

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Here is the source code for NonRectangularShellFromTransparencyImage.java

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/*******************************************************************************
 * Copyright (c) 2000, 2005 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;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Region;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

/**
 * Region snippet: Create non-rectangular shell from an image with transparency
 * 
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */
public class NonRectangularShellFromTransparencyImage {
    public static void main(String[] args) {
        final Display display = new Display();
        final Image image = display.getSystemImage(SWT.ICON_INFORMATION);
        final Shell shell = new Shell(display, SWT.NO_TRIM);
        Region region = new Region();
        final ImageData imageData = image.getImageData();
        if (imageData.alphaData != null) {
            Rectangle pixel = new Rectangle(0, 0, 1, 1);
            for (int y = 0; y < imageData.height; y++) {
                for (int x = 0; x < imageData.width; x++) {
                    if (imageData.getAlpha(x, y) == 255) {
                        pixel.x = imageData.x + x;
                        pixel.y = imageData.y + y;
                        region.add(pixel);
                    }
                }
            }
        } else {
            ImageData mask = imageData.getTransparencyMask();
            Rectangle pixel = new Rectangle(0, 0, 1, 1);
            for (int y = 0; y < mask.height; y++) {
                for (int x = 0; x < mask.width; x++) {
                    if (mask.getPixel(x, y) != 0) {
                        pixel.x = imageData.x + x;
                        pixel.y = imageData.y + y;
                        region.add(pixel);
                    }
                }
            }
        }
        shell.setRegion(region);

        Listener l = new Listener() {
            int startX, startY;

            public void handleEvent(Event e) {
                if (e.type == SWT.KeyDown && e.character == SWT.ESC) {
                    shell.dispose();
                }
                if (e.type == SWT.MouseDown && e.button == 1) {
                    startX = e.x;
                    startY = e.y;
                }
                if (e.type == SWT.MouseMove && (e.stateMask & SWT.BUTTON1) != 0) {
                    Point p = shell.toDisplay(e.x, e.y);
                    p.x -= startX;
                    p.y -= startY;
                    shell.setLocation(p);
                }
                if (e.type == SWT.Paint) {
                    e.gc.drawImage(image, imageData.x, imageData.y);
                }
            }
        };
        shell.addListener(SWT.KeyDown, l);
        shell.addListener(SWT.MouseDown, l);
        shell.addListener(SWT.MouseMove, l);
        shell.addListener(SWT.Paint, l);

        shell.setSize(imageData.x + imageData.width, imageData.y + imageData.height);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        region.dispose();
        image.dispose();
        display.dispose();
    }
}