/*
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
import java.awt.*;
import java.applet.Applet;

/* 
 * This applet displays several images in a row.  It prevents
 * flashing by double buffering.  However, it doesn't wait until
 * the images are fully loaded 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;
    int delay;
    Thread animatorThread;

    Dimension offDimension;
    Image offImage;
    Graphics offGraphics;

    Image images[];

    public void init() {
        String str;

        // How many milliseconds between frames?
        str = getParameter("fps");
        int fps = (str != null) ? Integer.parseInt(str) : 10;
        delay = (fps > 0) ? (1000 / fps) : 100;

        // Load all the images.
        images = new Image[10];
        for (int i = 1; i <= 10; i++) {
            images[i-1] = getImage(getCodeBase(),
                                       "../../../images/duke/T"+i+".gif");
        }
    }

    public void start() {
        if (animatorThread == null) {
            animatorThread = new Thread(this);
            animatorThread.start();
        }
    }

    public void stop() {
        animatorThread = null;
        offImage = null;
        offGraphics = null;
    }

    public boolean mouseDown(Event e, int x, int y) {
        if (animatorThread == null) {
            start();
        }
        else {
            stop();
        }
        return false;
    }

    public void run() {
        // Remember the starting time
        long startTime = System.currentTimeMillis();

        while (Thread.currentThread() == animatorThread) {
            // Display the next frame of animation.
            repaint();

            // Delay depending on how far we are behind.
            try {
                startTime += delay;
                Thread.sleep(Math.max(0, 
                                      startTime-System.currentTimeMillis()));
            } catch (InterruptedException e) {
                break;
            } 
            frameNumber++;
        }
    }

    // Paint the previous frame (if any).
    public void paint(Graphics g) {
        if (offImage != null) {
            g.drawImage(offImage, 0, 0, this);
        }
    }

    public void update(Graphics g) {
        Dimension d = size();

        // 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.
        offGraphics.drawImage(images[frameNumber % 10], 0, 0, this);

        // Paint the image onto the screen.
        g.drawImage(offImage, 0, 0, this);
    }
}