如何用mousewheellistener调整许多jpanels的大小？

Question

我在Jlayeredpane中有三个Jpanels，我在Jlayeredpane中添加了mousewheellistener。当我创建一个事件时，所有组件（包括Jpanel中的三个Jpanel和组件）将调整大小（变大或变小），我尝试了很多方法，但是我无法解决，谁能举个例子？谢谢！

// Jlayeredpane

package test;

import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ActionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.geom.Rectangle2D;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;

import test.MouseWheelListener;

public class MapView extends JPanel {
    private Dimension preferredSize = new Dimension(930, 600);
    private JLayeredPane jLayeredPane = new JLayeredPane();
    private JPanel bgPanel = new JPanel();//bgPanel
    private JPanel roomPanel = new JPanel();//roomPanel
    private JPanel infoPanel = new JPanel();//infoPanel
    private Rectangle2D[] rects = new Rectangle2D[50];
    private ImageIcon imageIcon;

    public MapView() throws IOException {

        File imageFile = new File("res"+File.separator+"OK1.jpg");
        final Image image = ImageIO.read(imageFile);
        imageIcon = new ImageIcon(image.getScaledInstance(
                getPreferredSize().width, getPreferredSize().height,
                Image.SCALE_FAST));
        final JLabel bg = new JLabel(imageIcon);
        final Point origin = new Point(0, 0);
        final Rectangle rectangle = new Rectangle(origin, getPreferredSize());
        bgPanel.setBounds(rectangle);
        bgPanel.add(bg);

        setPreferredSize(getPreferredSize());
        JButton jButton = new JButton("test");
        bgPanel.setOpaque(false);
        roomPanel.setOpaque(false);
        infoPanel.setOpaque(false);
        roomPanel.setBounds(rectangle);
        infoPanel.setBounds(rectangle);
        add(bgPanel, new Integer(1));
        add(roomPanel, new Integer(2));
        add(infoPanel, new Integer(3));


        for (int i = 0; i < rects.length; i++) {
            rects[i] = new Rectangle2D.Double(Math.random() * .8,
                    Math.random() * .8, Math.random() * .2, Math.random() * .2);
        }
        MouseWheelListener mouseWheelListener = new MouseWheelListener(this,
                getPreferredSize());
        addMouseWheelListener(mouseWheelListener);

    }

    public Dimension getPreferredSize() {
        return preferredSize;
    }

    private Rectangle2D r = new Rectangle2D.Float();

    public void paint(Graphics g) {
        super.paint(g);
        g.setColor(Color.red);
        int w = getWidth();
        int h = getHeight();
        for (Rectangle2D rect : rects) {
            r.setRect(rect.getX() * w, rect.getY() * h, rect.getWidth() * w,
                    rect.getHeight() * h);
            ((Graphics2D) g).draw(r);
        }
    }

}

// mousewheellistener

package test;

import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.MouseWheelEvent;
import java.util.Map;

import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class MouseWheelListener implements java.awt.event.MouseWheelListener {

    private JPanel panel;
    private Dimension preferredSize = new Dimension(960, 680);

    public MouseWheelListener(JPanel panel,Dimension preferredSize) {
        this.panel = panel;
        this.preferredSize=preferredSize;
    }

    @Override
    public void mouseWheelMoved(MouseWheelEvent e) {
        updatePreferredSize(e.getWheelRotation(), e.getPoint());
    }

    private void updatePreferredSize(int wheelRotation, Point stablePoint) {
        double scaleFactor = findScaleFactor(wheelRotation);
        scaleBy(scaleFactor);
        Point offset = findOffset(stablePoint, scaleFactor);
        offsetBy(offset);
        panel.getParent().doLayout();
    }

    private double findScaleFactor(int wheelRotation) {
        double d = wheelRotation * 1.08;
        return (d > 0) ? 1 / d : -d;
    }

    private void scaleBy(double scaleFactor) {
        int w = (int) (panel.getWidth() * scaleFactor);
        int h = (int) (panel.getHeight() * scaleFactor);
        preferredSize.setSize(w, h);
    }

    private Point findOffset(Point stablePoint, double scaleFactor) {
        int x = (int) (stablePoint.x * scaleFactor) - stablePoint.x;
        int y = (int) (stablePoint.y * scaleFactor) - stablePoint.y;
        return new Point(x, y);
    }

    private void offsetBy(Point offset) {
        Point location = panel.getLocation();
        panel.setLocation(location.x - offset.x, location.y - offset.y);
    }
}

//测试Jframe

package test;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Image;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.WindowConstants;

public class Test extends JFrame {
    private Container main = this.getContentPane();

    public Test() {

        this.setTitle("TEST");
        this.setSize((int) (960), (int) (680));
        this.setLocation(0, 0); 
        this.setResizable(false);
        this.setUndecorated(false);
        this.setLocationRelativeTo(null);
        this.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

    }


    public void init() throws IOException {

        initContent();
        this.setVisible(true);
    }

    private void initContent() throws IOException {
        MapView mapPanel = new MapView();
        JScrollPane infoPanel = new JScrollPane(mapPanel);
        this.addKeyListener(new KeyListener(mapPanel));
        main.add(infoPanel, BorderLayout.CENTER);
    }
    public static void main(String[] args) throws IOException {

        Test window = new Test();
        window.init();
    }
}