Swing I - Java - page 918

Display 17.11 Using Panels (part 2 of 4)

22 public PanelDemo()

23 {

24 super ("Panel Demonstration");

25 setSize(WIDTH, HEIGHT);

26 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

27 setLayout( new BorderLayout());

28 JPanel biggerPanel = new JPanel();

29 biggerPanel.setLayout( new GridLayout(1, 3));

30 greenPanel = new JPanel();

31 greenPanel.setBackground(Color.LIGHT_GRAY);

32 biggerPanel.add(greenPanel);

33 whitePanel = new JPanel();

34 whitePanel.setBackground(Color.LIGHT_GRAY);

35 biggerPanel.add(whitePanel);

36 grayPanel = new JPanel();

37 grayPanel.setBackground(Color.LIGHT_GRAY);

38 biggerPanel.add(grayPanel);

39 add(biggerPanel, BorderLayout.CENTER);

40 JPanel buttonPanel = new JPanel();

41 buttonPanel.setBackground(Color.LIGHT_GRAY);

42 buttonPanel.setLayout( new FlowLayout());

43 JButton greenButton = new JButton("Green");

44 greenButton.setBackground(Color.GREEN);

An object of the class
PanelDemo is the action
listener for the buttons in
that object.

45 greenButton.addActionListener( this );

46 buttonPanel.add(greenButton);

47 JButton whiteButton = new JButton("White");

48 whiteButton.setBackground(Color.WHITE);

49 whiteButton.addActionListener( this );

50 buttonPanel.add(whiteButton);

51 JButton grayButton = new JButton("Gray");

52 grayButton.setBackground(Color.GRAY);

53 grayButton.addActionListener( this );

54 buttonPanel.add(grayButton);

55 add(buttonPanel, BorderLayout.SOUTH);

56 }