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Java > Open Source Codes > foxtrot > examples > SimpleExample


1 /**
2  * Copyright (c) 2002-2005, Simone Bordet
3  * All rights reserved.
4  *
5  * This software is distributable under the BSD license.
6  * See the terms of the BSD license in the documentation provided with this software.
7  */
8
9 package foxtrot.examples;
10
11 import java.awt.Container JavaDoc;
12 import java.awt.Dimension JavaDoc;
13 import java.awt.GridBagLayout JavaDoc;
14 import java.awt.Toolkit JavaDoc;
15 import java.awt.event.ActionEvent JavaDoc;
16 import java.awt.event.ActionListener JavaDoc;
17
18 import javax.swing.JButton JavaDoc;
19 import javax.swing.JFrame JavaDoc;
20
21 import foxtrot.Task;
22 import foxtrot.Worker;
23
24 /**
25  * A very simple example that shows Swing limits. <br>
26  * A button executes a time-consuming task, and when executing this task the same button is used to
27  * interrupt the task. <br>
28  * This is impossible to do with plain Swing, but easy with Foxtrot.
29  *
30  * For a comparison, look at the freezeSleep method and to the workerSleep method, and try to run the
31  * example one time with one method, and one time with the other.
32  *
33  * @version $Revision: 1.6 $
34  */
35 public class SimpleExample extends JFrame JavaDoc
36 {
37    private boolean sleeping;
38    private JButton JavaDoc button;
39
40    public static void main(String JavaDoc[] args)
41    {
42       SimpleExample example = new SimpleExample();
43       example.setVisible(true);
44    }
45
46    public SimpleExample()
47    {
48       super("Foxtrot Example");
49
50       button = new JButton JavaDoc("Take a nap !");
51       button.addActionListener(new ActionListener JavaDoc()
52       {
53          public void actionPerformed(ActionEvent JavaDoc e)
54          {
55             if (sleeping)
56                wakeUp();
57             else
58                sleep();
59          }
60       });
61
62       setDefaultCloseOperation(EXIT_ON_CLOSE);
63
64       Container JavaDoc c = getContentPane();
65       c.setLayout(new GridBagLayout JavaDoc());
66       c.add(button);
67
68       setSize(300, 200);
69
70       Dimension JavaDoc screen = Toolkit.getDefaultToolkit().getScreenSize();
71       Dimension JavaDoc size = getSize();
72       int x = (screen.width - size.width) >> 1;
73       int y = (screen.height - size.height) >> 1;
74       setLocation(x, y);
75    }
76
77    private void sleep()
78    {
79       button.setText("Wake me up!");
80       workerSleep();
81 // freezeSleep();
82 button.setText("Take a nap!");
83    }
84
85    private void workerSleep()
86    {
87       try
88       {
89          Worker.post(new Task()
90          {
91             public Object JavaDoc run() throws InterruptedException JavaDoc
92             {
93                synchronized (SimpleExample.this)
94                {
95                   sleeping = true;
96                   SimpleExample.this.wait();
97                   sleeping = false;
98                }
99                return null;
100             }
101          });
102       }
103       catch (InterruptedException JavaDoc x)
104       {
105          x.printStackTrace();
106       }
107       catch (Exception JavaDoc x)
108       {
109          // Never thrown
110 }
111    }
112
113    private void freezeSleep()
114    {
115       try
116       {
117          synchronized (this)
118          {
119             sleeping = true;
120             wait();
121             sleeping = false;
122          }
123       }
124       catch (InterruptedException JavaDoc x)
125       {
126          x.printStackTrace();
127       }
128    }
129
130    private void wakeUp()
131    {
132       synchronized (this)
133       {
134          notifyAll();
135       }
136    }
137 }
138
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