More on listeners - An Introduction to Graphical User Interfaces with Java Swing - page 91

File: its/CleanUpFrame/CleanUpFrame.java

package its.CleanUpFrame; 1.

2.
3. import javax.swing.JFrame;

4.

import java.awt.event.WindowAdapter;

5.

import java.awt.event.WindowEvent;

6.
7. public class CleanUpFrame extends JFrame

8.

{

9.

public CleanUpFrame()

10.

{

11.

this .setSize(200,200);

12.

this .setLocation(200,200);

13.

this .setTitle("CleanUpFrame");

14.

CleanUpAdapter cleaner = new CleanUpAdapter();

15.

this .addWindowListener(cleaner);

16.

}

17.
18.

public void showIt(){

this .setVisible( true ); 19.

} 20.

21.
22.

public void hideIt(){

this .setVisible( false ); 23.

} 24.

25.
26. // Performs the clean up work before terminating the application.

27.

private static void cleanUp(){

28.

// Real code for the clean up goes here.

29.

System.out.println("Cleaning up and then terminating the program.");

30.

System.exit(0);

31.

}

32.

// Internal class

33.

private class CleanUpAdapter extends WindowAdapter{

34.
35. public void windowClosing(WindowEvent we)

36.

{

37.

// Call the cleanUp method of the frame.

38.

cleanUp();

39.

}

40.

}// internal class

} 41.