mouselistenerdemo.java

《java事件处理指南》一书的代码,好东西

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MouseListenerDemo extends JFrame 
                              implements MouseListener
{
   private JButton button;

   public MouseListenerDemo()
   {
/*  A JButton is added to a JFrame.  The button registers       */
/*  a MouseListener.  Since the MouseListenerDemo class         */
/*  itself serves as the MouseListener, the addMouseListener()  */
/*  method is passed the "this" reference.                      */

      button = new JButton("help");
      button.setBorder(BorderFactory.createRaisedBevelBorder());
      button.setBackground(Color.lightGray);
      button.addMouseListener(this);

      JPanel panel = new JPanel();
      panel.add(button);

      getContentPane().add(panel);

      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setBounds(100, 100, 200, 200);
      setVisible(true);
   }

/*  Since the MouseListenerDemo class serves as the MouseListener  */
/*  all of the implementations of the methods declared in the      */
/*  MouseListener interface are implemented inside the             */
/*  MouseListenerDemo class.  These methods are used to change     */
/*  the background color of the JButton depending on what the      */
/*  mouse is doing.  The mouseClicked() method is not used, so     */
/*  it is implemented as a stub method.                            */

   public void mouseEntered(MouseEvent event)
   {
      button.setBackground(Color.pink);
   }

   public void mouseExited(MouseEvent event)
   {
      button.setBackground(Color.lightGray);
   }

   public void mousePressed(MouseEvent event)
   {
      button.setBackground(Color.red);
   }

   public void mouseReleased(MouseEvent event)
   {
      button.setBackground(Color.pink);
   }

   public void mouseClicked(MouseEvent event) {}

   public static void main(String args[])
   {
      MouseListenerDemo demo = new MouseListenerDemo();
   }
}