在Java程序，如何实现自适应位置的快捷菜单

做界面时，常用到快捷菜单(JPopupMenu), 可JPopupMenu本身没办法根据鼠标位置来自动调整菜单位置使全部菜单可见，为此我专门写了一个可自适应位置的快捷菜单，代码如下：

import javax.swing.*;

import java.awt.*;

/**

* <p>Copyright: Copyright (c) 2002</p>

* @author Turbo Chen

* @version 1.01

*/

public class CJPopupMenu extends JPopupMenu

{

public void show(Component invoker,int x, int y)

{

Point ps = invoker.getLocationOnScreen();

Dimension d = Toolkit.getDefaultToolkit().getScreenSize();

int mw = this.getPreferredSize().width;

int mh = this.getPreferredSize().height;

int newX = x;

int newY = y;

int aX = ps.x+x+mw;

int aY = ps.y+y+mh;

if ( aX>d.width )

newX = x -(aX - d.width);

if ( aY>d.height )

newY = y -(aY - d.height);

super.show(invoker,newX,newY);

}

}

这个类重载了public void show(Component invoker,int x, int y)方法来实现自适应位置功能.