import java.awt.*; import java.applet.Applet; /* * Based on Arthur van Hoff's animation examples, this applet * can serve as a template for all animation applets. */ public class AnimatorApplet extends Applet implements Runnable { int frameNumber = -1; int delay; Thread animatorThread; boolean frozen = false; public void init() { String str = getParameter("fps"); int fps = (str != null) ? Integer.parseInt(str) : 10; delay = (fps > 0) ? (1000 / fps) : 100; } public void start() { if (frozen) { //Do nothing. The user has requested that we //stop changing the image. } else { //Start animating! if (animatorThread == null) { animatorThread = new Thread(this); } animatorThread.start(); } } public void stop() { animatorThread = null; } public boolean mouseDown(Event e, int x, int y) { if (frozen) { frozen = false; start(); } else { frozen = true; stop(); } return true; } public void run() { //Just to be nice, lower this thread's priority //so it can't interfere with other processing going on. Thread.currentThread().setPriority(Thread.MIN_PRIORITY); //Remember the starting time. long startTime = System.currentTimeMillis(); while (Thread.currentThread() == animatorThread) { //Advance the animation frame. frameNumber++; //Display it. repaint(); //Delay depending on how far we are behind. try { startTime += delay; Thread.sleep(Math.max(0, startTime-System.currentTimeMillis())); } catch (InterruptedException e) { break; } } } public void paint(Graphics g) { g.drawString("Frame " + frameNumber, 0, 30); } }