animate.java

Java Threads, 2Ed (Source）

/*
 *
 * Copyright (c) 1997-1999 Scott Oaks and Henry Wong. 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.
 *
 * This sample source code is provided for example only,
 * on an unsupported, as-is basis. 
 *
 * AUTHOR 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. AUTHOR SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 * THIS SOFTWARE IS NOT DESIGNED OR INTENDED FOR USE OR RESALE AS ON-LINE
 * CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING FAIL-SAFE
 * PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT
 * NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
 * SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
 * SOFTWARE COULD LEAD DIRECTLY TO DEATH, PERSONAL INJURY, OR SEVERE
 * PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES").  AUTHOR
 * SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
 * HIGH RISK ACTIVITIES.
 */


import java.applet.*;
import java.awt.*;

public class Animate extends Applet implements Runnable {
    int count, lastcount;
    Image pictures[];
    Thread timer;

    public void init() {
        lastcount = 10; count = 0;
        pictures = new Image[10];
        MediaTracker tracker = new MediaTracker(this);
        for (int a = 0; a < lastcount; a++) {
            pictures[a] = getImage (
                getCodeBase(), new Integer(a).toString()+".jpeg");
            tracker.addImage(pictures[a], 0);
        }
        tracker.checkAll(true);
    }

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

    public void paint(Graphics g) {
        g.drawImage(pictures[count++], 0, 0, null);
        if (count == lastcount) count = 0; 
    }

    public void run() {
        while (isActive()) {
            try {
                repaint();
                Thread.sleep(1000);
            } catch (Exception e) {}
        }
        timer = null;
    }    
}