org.eclipse.swt.snippets.Snippet141.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet141.java

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/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.snippets;

import java.util.concurrent.atomic.*;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

/*
 * Image example snippet: display an animated GIF
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
public class Snippet141 {
    static Display display;
    static Shell shell;
    static GC shellGC;
    static Color shellBackground;
    static ImageLoader loader;
    static ImageData[] imageDataArray;
    static Thread animateThread;
    static Image image;
    static final boolean useGIFBackground = false;

    public static void main(String[] args) {
        display = new Display();
        shell = new Shell(display);
        shell.setText("Snippet 141");
        shell.setSize(300, 300);
        shell.open();
        shellGC = new GC(shell);
        shellBackground = shell.getBackground();

        FileDialog dialog = new FileDialog(shell);
        dialog.setFilterExtensions(new String[] { "*.gif" });
        String fileName = dialog.open();
        final AtomicBoolean stopAnimation = new AtomicBoolean(false);
        if (fileName != null) {
            loader = new ImageLoader();
            try {
                imageDataArray = loader.load(fileName);
                if (imageDataArray.length > 1) {
                    animateThread = new Thread("Animation") {
                        @Override
                        public void run() {
                            /* Create an off-screen image to draw on, and fill it with the shell background. */
                            Image offScreenImage = new Image(display, loader.logicalScreenWidth,
                                    loader.logicalScreenHeight);
                            GC offScreenImageGC = new GC(offScreenImage);
                            offScreenImageGC.setBackground(shellBackground);
                            offScreenImageGC.fillRectangle(0, 0, loader.logicalScreenWidth,
                                    loader.logicalScreenHeight);

                            try {
                                /* Create the first image and draw it on the off-screen image. */
                                int imageDataIndex = 0;
                                ImageData imageData = imageDataArray[imageDataIndex];
                                if (image != null && !image.isDisposed())
                                    image.dispose();
                                image = new Image(display, imageData);
                                offScreenImageGC.drawImage(image, 0, 0, imageData.width, imageData.height,
                                        imageData.x, imageData.y, imageData.width, imageData.height);

                                /* Now loop through the images, creating and drawing each one
                                 * on the off-screen image before drawing it on the shell. */
                                int repeatCount = loader.repeatCount;
                                while ((loader.repeatCount == 0 || repeatCount > 0) && !stopAnimation.get()) {
                                    switch (imageData.disposalMethod) {
                                    case SWT.DM_FILL_BACKGROUND:
                                        /* Fill with the background color before drawing. */
                                        Color bgColor = null;
                                        if (useGIFBackground && loader.backgroundPixel != -1) {
                                            bgColor = new Color(display,
                                                    imageData.palette.getRGB(loader.backgroundPixel));
                                        }
                                        offScreenImageGC.setBackground(bgColor != null ? bgColor : shellBackground);
                                        offScreenImageGC.fillRectangle(imageData.x, imageData.y, imageData.width,
                                                imageData.height);
                                        if (bgColor != null)
                                            bgColor.dispose();
                                        break;
                                    case SWT.DM_FILL_PREVIOUS:
                                        /* Restore the previous image before drawing. */
                                        offScreenImageGC.drawImage(image, 0, 0, imageData.width, imageData.height,
                                                imageData.x, imageData.y, imageData.width, imageData.height);
                                        break;
                                    }

                                    imageDataIndex = (imageDataIndex + 1) % imageDataArray.length;
                                    imageData = imageDataArray[imageDataIndex];
                                    image.dispose();
                                    image = new Image(display, imageData);
                                    offScreenImageGC.drawImage(image, 0, 0, imageData.width, imageData.height,
                                            imageData.x, imageData.y, imageData.width, imageData.height);

                                    /* Draw the off-screen image to the shell. */
                                    shellGC.drawImage(offScreenImage, 0, 0);

                                    /* Sleep for the specified delay time (adding commonly-used slow-down fudge factors). */
                                    try {
                                        int ms = imageData.delayTime * 10;
                                        if (ms < 20)
                                            ms += 30;
                                        if (ms < 30)
                                            ms += 10;
                                        Thread.sleep(ms);
                                    } catch (InterruptedException e) {
                                    }

                                    /* If we have just drawn the last image, decrement the repeat count and start again. */
                                    if (imageDataIndex == imageDataArray.length - 1)
                                        repeatCount--;
                                }
                            } catch (SWTException ex) {
                                System.out.println("There was an error animating the GIF");
                            } finally {
                                if (offScreenImage != null && !offScreenImage.isDisposed())
                                    offScreenImage.dispose();
                                if (offScreenImageGC != null && !offScreenImageGC.isDisposed())
                                    offScreenImageGC.dispose();
                                if (image != null && !image.isDisposed())
                                    image.dispose();
                            }
                        }
                    };
                    animateThread.setDaemon(true);
                    animateThread.start();
                }
            } catch (SWTException ex) {
                System.out.println("There was an error loading the GIF");
            }
        }

        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        stopAnimation.set(true);
        display.dispose();
    }
}