Swing II - Absolute Java - page 1038

EXAMPLE: (continued)

In this GUI, a label becomes visible or invisible when a button is clicked. For
example, the following code from the method actionPerformed in Display 18.9
determines what happens when the button with the text "Wave" on it is clicked:

if (actionCommand.equals("Wave"))
{

wavingLabel.setVisible( true );
standingLabel.setVisible( false );
}
We used the setVisible method on the labels containing the icons rather than
directly on the icons because the class ImageIcon does not have the setVisible
method.
The two statements

wavingLabel.setVisible( true );
standingLabel.setVisible( false );

make wavingLabel visible and standingLabel invisible.

Display 18.9 Labels with Changing Visibility (part 1 of 3)

1 import javax.swing.JFrame;
2 import javax.swing.ImageIcon;
3 import javax.swing.JPanel;
4 import javax.swing.JLabel;
5 import javax.swing.JButton;
6 import java.awt.BorderLayout;
7 import java.awt.FlowLayout;
8 import java.awt.Color;
9 import java.awt.event.ActionListener;
10 import java.awt.event.ActionEvent;

11 public class VisibilityDemo extends JFrame
12

implements ActionListener

13 {
14 public static final int WIDTH = 300;

15 public static final int HEIGHT = 200;

16 private JLabel wavingLabel;

17 private JLabel standingLabel;