Display an animated GIF
/*
* Image example snippet: display an animated GIF
*
* For a list of all SWT example snippets see
* http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
*/
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;
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.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();
}
}
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