/*
 * 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;

/* 
 * Based on Arthur van Hoff's animation examples, this applet
 * can serve as a template for all animation applets.
 */
// Does this do everything necessary to avoid thread problems?
public class AnimatorApplet extends Applet implements Runnable {
    int frameNumber;
    int delay;
    Thread animatorThread;

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

    public void stop() {
	animatorThread = 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;
	    }

	    // Advance the frame
	    frameNumber++;
	}
    }

    public void paint(Graphics g) {
	g.drawString("Frame " + frameNumber, 0, 30);
    }
}