1 /*
2 * Gary Cornell and Cay S. Horstmann, Core Java (Book/CD-ROM)
3 * Published By SunSoft Press/Prentice-Hall
4 * Copyright (C) 1996 Sun Microsystems Inc.
5 * All Rights Reserved. ISBN 0-13-565755-5
6 *
7 * Permission to use, copy, modify, and distribute this
8 * software and its documentation for NON-COMMERCIAL purposes
9 * and without fee is hereby granted provided that this
10 * copyright notice appears in all copies.
11 *
12 * THE AUTHORS AND PUBLISHER MAKE NO REPRESENTATIONS OR
13 * WARRANTIES ABOUT THE SUITABILITY OF THE SOFTWARE, EITHER
14 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
16 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. THE AUTHORS
17 * AND PUBLISHER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED
18 * BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
19 * THIS SOFTWARE OR ITS DERIVATIVES.
20 */
21
22 /**
23 * @version 1.00 07 Feb 1996
24 * @author Cay Horstmann
25 */
26
27 import java.awt.*;
28
29 public class BounceThread extends Frame
30 { public BounceThread()
31 { setTitle("BounceThread");
32 canvas = new Canvas();
33 add("Center", canvas);
34 Panel p = new Panel();
35 p.add(new Button("Start"));
36 p.add(new Button("Close"));
37 add("South", p);
38 }
39
40 public boolean handleEvent(Event evt)
41 { if (evt.id == Event.WINDOW_DESTROY) System.exit(0);
42 return super.handleEvent(evt);
43 }
44
45 public boolean action(Event evt, Object arg)
46 { if (arg.equals("Start"))
47 { Ball b = new Ball(canvas);
48 b.start();
49 }
50 else if (arg.equals("Close"))
51 System.exit(0);
52 else return super.action(evt, arg);
53 return true;
54 }
55
56 public static void main(String[] args)
57 { Frame f = new BounceThread();
58 f.resize(300, 200);
59 f.show();
60 }
61
62 private Canvas canvas;
63 }
64
65 class Ball extends Thread
66 { public Ball(Canvas c) { box = c; }
67
68 public void draw()
69 { Graphics g = box.getGraphics();
70 g.fillOval(x, y, XSIZE, YSIZE);
71 g.dispose();
72 }
73
74 public void move()
75 { Graphics g = box.getGraphics();
76 g.setXORMode(box.getBackground());
77 g.fillOval(x, y, XSIZE, YSIZE);
78 x += dx;
79 y += dy;
80 Dimension d = box.size();
81 if (x < 0) { x = 0; dx = -dx; }
82 if (x + XSIZE >= d.width) { x = d.width - XSIZE; dx = -dx; }
83 if (y < 0) { y = 0; dy = -dy; }
84 if (y + YSIZE >= d.height) { y = d.height - YSIZE; dy = -dy; }
85 g.fillOval(x, y, XSIZE, YSIZE);
86 g.dispose();
87 }
88
89 public void run()
90 { draw();
91 for (int i = 1; i <= 1000; i++)
92 { move();
93 try { Thread.sleep(5); } catch(InterruptedException e) {}
94 }
95 }
96
97 private Canvas box;
98 private static final int XSIZE = 10;
99 private static final int YSIZE = 10;
100 private int x = 0;
101 private int y = 0;
102 private int dx = 2;
103 private int dy = 2;
104 }
105
106