Source of ButtonDemo.java


  1: 
  2: import javax.swing.*;
  3: import java.awt.*;
  4: import java.awt.event.*;
  5: 
  6: /**
  7:  Simple demonstration of putting buttons in a JFrame.
  8: */
  9: public class ButtonDemo extends JFrame implements ActionListener
 10: {
 11:     public static final int WIDTH = 300;
 12:     public static final int HEIGHT = 200;
 13: 
 14:     /**
 15:      Creates and displays a window of the class ButtonDemo.
 16:     */
 17:     public static void main(String[] args)
 18:     {
 19:         ButtonDemo buttonGui = new ButtonDemo( );
 20:         buttonGui.setVisible(true);
 21:     }
 22: 
 23:     public ButtonDemo( )
 24:     {
 25:         setSize(WIDTH, HEIGHT);
 26: 
 27:         addWindowListener(new WindowDestroyer( ));
 28:         setTitle("Button Demo");
 29:         Container contentPane = getContentPane( );
 30:         contentPane.setBackground(Color.BLUE);
 31: 
 32:         contentPane.setLayout(new FlowLayout( ));
 33: 
 34:         JButton stopButton = new JButton("Red");
 35:         stopButton.addActionListener(this);
 36:         contentPane.add(stopButton);
 37: 
 38:         JButton goButton = new JButton("Green");
 39:         goButton.addActionListener(this);
 40:         contentPane.add(goButton);
 41:     }
 42: 
 43:     public void actionPerformed(ActionEvent e)
 44:     {
 45:        Container contentPane = getContentPane( );
 46: 
 47:        if (e.getActionCommand( ).equals("Red"))
 48:            contentPane.setBackground(Color.RED);
 49:        else if (e.getActionCommand( ).equals("Green"))
 50:            contentPane.setBackground(Color.GREEN);
 51:        else
 52:            System.out.println("Error in button interface.");
 53:     }
 54: }
 55: