Display an animated GIF : PNG GIF « SWT 2D Graphics « Java Tutorial





/*******************************************************************************
 * 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;
/*
 * Image example snippet: display an animated GIF
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageLoader;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.FileDialog;
import org.eclipse.swt.widgets.Shell;

public class AnimatedGIFDisplay {
  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.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();
    if (fileName != null) {
      loader = new ImageLoader();
      try {
        imageDataArray = loader.load(fileName);
        if (imageDataArray.length > 1) {
          animateThread = new Thread("Animation") {
            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) {
                  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();
    }
    display.dispose();
  }
}










18.18.PNG GIF
18.18.1.Display an animated GIF
18.18.2.Write an animated GIF to a file
18.18.3.Write an Image to a PNG file