Painting, overlapping and hiding

Question

Hi, guys
I want to write a graphic editor, just like Paint of windows.
JFrame frame : the main frame
JPanel panelWest: the tool bar in the west
JPanel panelNorth: the tool bar in the north
JPanel panelCenter: the main edit panel
JMenuBar menuBar:
and add all the stuff into frame. I did not overwrite the paint() methods for frame, panelNorth,panelWest. On the other hand, I overwrite the paint() for panelCenter, letting it draw something.
Here is the problem: when i draw something in the panelCenter, the other component like menuBar, panelNorth and panelWest will be on the panelCenter. that is there are two menuBar, two panelNorth and tow panelWest.
I tried another way: I use Canvas instead of panelCenter, and the problem above is solved. But another problem rises: the canvas will be on the top of the other components, i.e., when click menu, the menuitems that overlaps with the canvas will be invisible.
Thanks!

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GUI extends JFrame{
     public GUI(){
          Container c=getContentPane();
          JPanel panelWest=new JPanel();
          JPanel panelNorth=new JPanel();
          MyPanel panelCenter=new MyPanel();
          JMenuBar mb=new JMenuBar();
          JMenu m1=new JMenu("File");
          JMenu m2=new JMenu("Edit");
          JMenu m3=new JMenu("Help");
          m1.add(new JMenuItem("Opne"));
          m1.add(new JMenuItem("Save"));
          m1.add(new JMenuItem("Print"));
          m1.add(new JMenuItem("Close"));
          m2.add(new JMenuItem("Copy"));
          m2.add(new JMenuItem("Paste"));
          m2.add(new JMenuItem("Cut"));
          m2.add(new JMenuItem("Delete"));
          m3.add(new JMenuItem("Help Content"));
          m3.add(new JMenuItem("About"));
          mb.add(m1);
          mb.add(m2);
          mb.add(m3);
          setJMenuBar(mb);
          panelWest.add(new JButton("B1"));
          panelNorth.add(new JButton("B2"));
          c.add(panelWest,"West");
          c.add(panelNorth,"North");
          c.add(panelCenter,"Center");
          setSize(300,200);
          show();
     public static void main(String args[]){
          new GUI();
class MyPanel extends JPanel{
     int x;
     int y;
     public MyPanel(){
          setBackground(Color.white);
          addMouseListener(
               new MouseAdapter(){
                    public void mousePressed(MouseEvent e){
                         x=e.getX();
                         y=e.getY();
                         repaint();
     public void paint(Graphics g){
          g.drawRect(x,y,30,30);
}