/* * 1.1 version. */ import java.awt.*; import java.awt.event.*; import java.applet.Applet; /* * This applet displays several images in a row. It prevents * flashing by double buffering. However, it doesn't wait * for the images to fully load before drawing them, which * causes the weird effect of the animation appearing from * the top down. */ public class ImageSequence extends Applet implements Runnable { int frameNumber = -1; int delay; Thread animatorThread; boolean frozen = false; Image images[]; Dimension offDimension; Image offImage; Graphics offGraphics; public void init() { String str; int fps = 10; //How many milliseconds between frames? str = getParameter("fps"); try { if (str != null) { fps = Integer.parseInt(str); } } catch (Exception e) {} delay = (fps > 0) ? (1000 / fps) : 100; //Get the images. images = new Image[10]; for (int i = 1; i images[i-1] = getImage(getCodeBase(), "T"+i+".gif"); } addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { if (frozen) { frozen = false; start(); } else { frozen = true; //Instead of calling stop(), which destroys the //backbuffer, just stop the animating thread. animatorThread = null; } } }); } 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() { //Stop the animating thread. animatorThread = null; //Get rid of the objects necessary for double buffering. offGraphics = null; offImage = null; } 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(); //Remember which thread we are. Thread currentThread = Thread.currentThread(); //This is the animation loop. while (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; } } } //Draw the current frame of animation. public void paint(Graphics g) { update(g); } public void update(Graphics g) { Dimension d = getSize(); //Create the offscreen graphics context, //if no good one exists. if ( (offGraphics == null) || (d.width != offDimension.width) || (d.height != offDimension.height) ) { offDimension = d; offImage = createImage(d.width, d.height); offGraphics = offImage.getGraphics(); } //Erase the previous image. offGraphics.setColor(getBackground()); offGraphics.fillRect(0, 0, d.width, d.height); offGraphics.setColor(Color.black); //Paint the frame into the image. try { offGraphics.drawImage(images[frameNumber%10], 0, 0, this); } catch(ArrayIndexOutOfBoundsException e) { //On rare occasions, this method can be called //when frameNumber is still -1. Do nothing. return; } //Paint the image onto the screen. g.drawImage(offImage, 0, 0, this); } }
