How can I use a layer system of images, boxes, lines etc

Question

Hi,
I trying to develop a map system which can have layers added and removed from screen at request.
I have a basic map picture which I would like to add a grid structure to which can be added and removed by the click of a JMenuItem.
My code looks like this:
package simulator.gui;
import java.awt.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
public class DrawMap extends Component {
     private static final long serialVersionUID = 1L;
     private BufferedImage map;
    public void paint(Graphics g) {
         Graphics2D g2 = (Graphics2D) g;
        g2.drawImage(map, simulator.values.Constants.originX, simulator.values.Constants.originY, null);
        g2.drawRect(simulator.values.Constants.originX, simulator.values.Constants.originY, simulator.values.Constants.mapWidth,simulator.values.Constants.mapHeight);
    public DrawMap() {
//       try {
//           map  = ImageIO.read(new File(simulator.values.Constants.map));
//       } catch (IOException e) {
    public Dimension getPreferredSize() {
        if (map == null) {
             return new Dimension(100,100);
        } else {
           return new Dimension(map.getWidth(), map.getHeight());
}I add the map to the window using this.add(new DrawMap());I want to have more methods such as DrawGrid() and DrawCircle() which get called separately from the DrawMap() method.
But when these get called they clear the screen and I can't get the over-layed effect I want.
Is there a solution to this?
I don't mind ever if I have to change most of my code.
Please help - it's for my final year project and this is just the basics of it!!!
Thanks,
- Kevin

Answer 1

There is quite a bit of information about using layers. Here is one:
http://java.sun.com/developer/Books/2dgraphics/chapter6.html
Just do some searching for more.
The question is not really suitable for forum answers, you need to do some research, study, and experimentation.