/** 
* @(#) ODTButtonEvent.java 
* 
* Copyright 2004 Opensource Develop Team. All rights reserved. 
*/ 

// package 
package com.opensource.event; 

// import classes 
import java.awt.AWTEvent; 

/** 
* 自定義按鈕事件。 
* 
* @author ODT 
* @version 1.0 06/05/2004 
* @see AWTEvent 
* @since JDK 1.3 
*/ 
public class ODTButtonEvent extends AWTEvent 
{ 
     public static final int ENTERED = 1; // 鼠標進入BUTTON 
l    public static final int EXITED = 2; // 鼠標退出BUTTON 
     public static final int PRESSED = 3; // 鼠標按下 
     public static final int RELEASED = 4; // 鼠標釋放 

     Object item;  
     int buttonState; 

     public ODTButtonEvent(ODTButtonable source, Object item, int buttonState) 
     { 
           super(source, -1); 
           this.item = item; 
           this.buttonState = buttonState; 
     } 

     public ODTButtonable getODTButtonable() 
     { 
           return (ODTButtonable) source; // 返回被監聽的對象 
     } 

     public Object getItem() 
     { 
           return item; 
     } 

     public int getButtonState() 
     { 
           return buttonState; // 返回按鈕狀態 
     } 

     public String paramString() 
     { 
           String s = null; 
           switch (buttonState) 
           { 
                 case ENTERED: 
                       s = "ENTERED"; 
                       break; 
                 case EXITED: 
                       s = "EXITED"; 
                       break; 
                 case PRESSED: 
                       s = "PRESSED"; 
                       break; 
                 case RELEASED: 
                       s = "RELEASED"; 
                       break; 
                 default: 
                       s = "unknown button state"; 
           } 

           return super.paramString() + " [button=" + s + "]"; 
     } 
} 


自定義監聽接口： 

代碼:
/** 
* @(#) ODTButtonListener.java 
* 
* Copyright 2004 Opensource Develop Team. All rights reserved. 
*/ 

// package 
package com.opensource.event; 

// import classes 
import java.util.EventListener; 

/** 
* 監聽ODTButtonEvent接口 
* 
* @author ODT 
* @version 1.0 06/05/2004 
* @see EventListener 
* @since JDK 1.3 
*/ 
public interface ODTButtonListener extends EventListener 
{ 
     void buttonStateChanged(ODTButtonEvent event); // 觸發事件 
}  


自定義構件注冊監聽器接口： 

代碼:
/** 
* @(#) ODTButtonable.java 
* 
* Copyright 2004 Opensource Develop Team. All rights reserved. 
*/ 

// package 
package com.opensource.event; 

// import classes 

/** 
* 構件實現此接口，可以擴展監聽者注冊感興趣的擴展事件 
* 
* @author ODT 
* @version 1.0 06/05/2004 
* @since JDK 1.3 
*/ 
public interface ODTButtonable 
{ 
     public void addButtonListener(ODTButtonListener l); // 注冊監聽器 
     public void removeButtonListener(ODTButtonListener l); // 取消監聽器 
}  


以上是對自定義事件機制的描述，下面是自定義組件。 

自定義組件： 


代碼:
/** 
* @(#) ODTButton.java 
* 
* Copyright 2004 Opensource Develop Team. All rights reserved. 
*/ 

// package 
package com.opensource.odt; 

// import classes 
import java.util.*; 
import java.awt.*; 
import java.awt.event.*; 

import com.opensource.event.*; 

/** 
* 實現ItemExpandable接口的構件 
* 
* @author ODT 
* @version 1.0 06/05/2004 
* @see Component 
* @see ODTButtonable 
* @since JDK 1.3 
*/ 
public class ODTButton extends Component implements ODTButtonable 
{ 
     private int stated; 
     private Vector listeners = new Vector();  

     public ODTButton() 
     { 
           addMouseListener(new MouseAdapter() 
           { 
                 public void mouseEntered(MouseEvent event) 
                 { 
                       stated = ODTButtonEvent.ENTERED; 
                       entered(stated); 
                       repaint(); 
                 } 

                 public void mousePressed(MouseEvent event) 
                 { 
                       stated = ODTButtonEvent.PRESSED; 
                       pressed(stated); 
                       repaint(); 
                 } 

                 public void mouseExited(MouseEvent event) 
                 { 
                       stated = ODTButtonEvent.EXITED; 
                       exited(stated); 
                       repaint(); 
                 } 
           }); 
     } 

     public void entered(int stated) 
     { 
           ODTButtonEvent e = new ODTButtonEvent(this, this, stated); 
           processButtonEvent(e); // 利用processButtonEvent(e)來觸發事件 
     } 

     public void pressed(int stated) 
     { 
           ODTButtonEvent e = new ODTButtonEvent(this, this, stated); 
           processButtonEvent(e); 
     } 

     public void exited(int stated) 
     { 
           ODTButtonEvent e = new ODTButtonEvent(this, this, stated); 
           processButtonEvent(e); 
     } 

     public void paint(Graphics g) 
     { 
           drawBorder(g); 
           drawContent(g); 
     } 

     public Dimension getPreferredSize() 
     { 
           return new Dimension(50, 20); 
     } 

     public void addButtonListener(ODTButtonListener l) 
     { 
           listeners.addElement(l); 
     } 

     public void removeButtonListener(ODTButtonListener l) 
     { 
           listeners.removeElement(l); 
     } 
      
     public synchronized void processButtonEvent(ODTButtonEvent event) 
     { 
           Enumeration e = listeners.elements(); 
           while (e.hasMoreElements()) 
           { 
                 ODTButtonListener l = (ODTButtonListener) e.nextElement(); 
                 l.buttonStateChanged(event); // 觸發事件 
           } 
     } 

     // 按鈕邊框 
     public void drawBorder(Graphics g) 
     { 
           Dimension size = getSize(); 
           g.setColor(new Color(174, 23, 145)); 
           g.drawRoundRect(0, 0, size.width-1, size.height-1, 5, 5); 
     } 
      
     // 改變按鈕顏色 
     public void drawContent(Graphics g) 
     { 
           Dimension size = getSize(); 
           if (stated == ODTButtonEvent.ENTERED) 
           { 
                 g.setColor(new Color(248, 199, 238)); 
           } 
           else 
                 g.setColor(new Color(236, 111, 210)); 

           g.fillRoundRect(1, 1, size.width-2, size.height-2, 5, 5); 
     } 
} 



測試自定義組件和事件： 


代碼:
/** 
* @(#) ODTButtonTest.java 
* 
* Copyright 2004 Opensource Develop Team. All rights reserved. 
*/ 

// package 
package com.opensource.odt; 

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

import com.opensource.event.*; 

/** 
* 測試自定義組件和事件代碼范例 
* 
* @author ODT 
* @version 1.0 06/05/2004 
* @see JFrame 
* @see ODTButtonListener 
* @since JDK 1.3 
*/ 
public class ODTButtonTest extends JFrame implements ODTButtonListener 
{ 
     public ODTButtonTest() 
     { 
           ODTButton button = new ODTButton(); 
           button.addButtonListener(this); // 注冊監聽器 
           getContentPane().setLayout(new FlowLayout()); 
           getContentPane().add(button); 
           getContentPane().setBackground(Color.WHITE); 
           setSize(400, 500); 
           setVisible(true); 
     } 
      
     // 所觸發的事件 
     public void buttonStateChanged(ODTButtonEvent event)  
     { 
           ODTButtonable ie = event.getODTButtonable(); 
           System.out.println(event.paramString()); 
     } 

     public static void main(String[] args) 
     { 
           new ODTButtonTest(); 
     } 
}