Swing I - Java - page 936

Display 17.16 Listeners as Inner Classes (part 2 of 3)

22 private class grayListener implements ActionListener

23 {

24 public void actionPerformed(ActionEvent e)

25 {

26 grayPanel.setBackground(Color.GRAY);

27 }

28 } //End of grayListener inner class

29 public static void main(String[] args)

30 {

31 InnerListenersDemo gui = new InnerListenersDemo();

32 gui.setVisible( true );

33 }

34 public InnerListenersDemo()

The resulting GUI is the same as in
Display 17.14.

35 {

36 super ("Menu Demonstration");

37 setSize(WIDTH, HEIGHT);

38 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

39 setLayout( new GridLayout(1, 3));

40 greenPanel = new JPanel();

41 greenPanel.setBackground(Color.LIGHT_GRAY);

42 add(greenPanel);

43 whitePanel = new JPanel();

44 whitePanel.setBackground(Color.LIGHT_GRAY);

45 add(whitePanel);

46 grayPanel = new JPanel();

47 grayPanel.setBackground(Color.LIGHT_GRAY);

48 add(grayPanel);

49 JMenu colorMenu = new JMenu("Add Colors");

50 JMenuItem greenChoice = new JMenuItem("Green");

51 greenChoice.addActionListener( new greenListener());

52 colorMenu.add(greenChoice);

53 JMenuItem whiteChoice = new JMenuItem("White");

54 whiteChoice.addActionListener( new WhiteListener());

55 colorMenu.add(whiteChoice);