J2SE的 JPanel实现点击缩放 ，然后可以拉动，类似于百度地图那种，有没有哪位有思路的呢？
求指导下，或者说下思路就行
谢谢了
比如这一个界面
我点击中间的部分
那么他就放大到2倍
但是又不能覆盖到周围的那3个Panel
值能通过鼠标拉动来查看放大后的整个Panel
求哪位同僚指点下 或者提供一个思路也可以，谢谢了！
------解决方案--------------------------------------------------------
- Java code
package map;import java.awt.BorderLayout;import java.awt.Color;import java.awt.Graphics;import java.awt.Graphics2D;import java.awt.Point;import java.awt.Toolkit;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.awt.event.MouseAdapter;import java.awt.event.MouseEvent;import java.awt.event.MouseWheelEvent;import java.awt.event.MouseWheelListener;import javax.swing.ImageIcon;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.border.EmptyBorder;public class Layer extends JPanel{ private static final long serialVersionUID = 1L; ImageIcon img = new ImageIcon(Toolkit.getDefaultToolkit().createImage("/root/桌面/2000.jpg")); //以下两个参数描述图层的位置 private int x = 0;// private int y = 0; //以下两个参数描述图层的大小 private int width = 300; private int height = 300; //以下两个参数描述图层的每次放大或缩小的尺寸 private int dx = 50; private int dy = 50; public Layer(){ this.addMouseWheelListener(new MouseWheelListener() { public void mouseWheelMoved(MouseWheelEvent e) { if(e.getWheelRotation() < 0){ zoom(); }else{ reduce(); } } }); MouseAdapter ma = new MouseAdapter(){ @Override public void mouseClicked(MouseEvent e) { zoom(); } boolean moveEnable = false; Point point1 = null; Point point2 = null; @Override public void mousePressed(MouseEvent e) { moveEnable = true; point1 = e.getPoint(); } @Override public void mouseReleased(MouseEvent e) { moveEnable = false; point1 = null; point2 = null; } @Override public void mouseMoved(MouseEvent e) { //System.out.println("move"); } @Override public void mouseDragged(MouseEvent e) { System.out.println("dragged"); point2 = e.getPoint(); if(moveEnable){ if(point1 != null && point2 != null){ int dx = point2.x - point1.x; int dy = point2.y - point1.y; x = x + dx; y = y + dy; //Layer.this.setLocation(_x, _y); point1 = point2; repaint(); } } } }; this.addMouseMotionListener(ma); this.addMouseListener(ma); } @Override public void paint(Graphics g) { //所有的图层变更都在此方法内响应 super.paint(g); Graphics2D g2 = (Graphics2D) g; g2.clearRect(0, 0, getBounds().width, getBounds().height); g2.drawImage(img.getImage(), x, y, width, height, null); } /** * 缩小 */ public void reduce(){ if(width > 2*dx && height > 2*dy){ x += dx; y += dy; width -= 2 * dx; height -= 2 * dy; super.repaint(); } } /** * 放大 */ public void zoom(){ x -= dx; y -= dy; width += 2 * dx; height += 2 * dy; super.repaint(); } /** * 测试方法 * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub JFrame f = new JFrame(); f.setLayout(new BorderLayout()); f.setSize(500, 500); final Layer layer = new Layer(); layer.setBorder(new EmptyBorder(2,2,2,2)); layer.setOpaque(true); layer.setBackground(Color.BLUE); layer.setSize(400, 400); f.getContentPane().add(layer); JButton btn1 = new JButton("放大"); btn1.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { layer.zoom(); } }); JButton btn2 = new JButton("缩小"); btn2.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { layer.reduce(); } }); f.add(btn1,BorderLayout.NORTH); f.add(btn2,BorderLayout.SOUTH); f.setVisible(true); }}