Chess game variant - help using JLayeredPane and the drag layer.

Question

Hi there!
I'm making a game based on chess, but with slightly different rules. The code at the bottom of this thread...
http://forum.java.sun.com/thread.jspa?forumID=57&threadID=518707
... forms the basis of the game board, and this is how I have implemented the dragging and dropping of pieces. My game, however is slightly different as there is a single neutral piece (the ball), which players can manipulate by moving one of their pieces to the square containing the ball, then moving the ball to another location.
When a player clicks and drags a piece to the ball square, then releases, I want to attach the 'ball' JLabel to the mouse so that the player can move it around the board WITHOUT holding down the mouse button. Then, when the player clicks again the ball is moved to the new square.
The only problem I have is attaching the 'ball' to the mouse so I can move it around (without the user having to hold the mouse button down). I thought about tried using the drag layer, but I couldn't quite get that working. I also thought about using the mouseMoved(MouseEvent e) and mouseClicked(MouseEvent e) methods.
I'm pretty new to this coding stuff, so any suggestions would be great.
Thanks!

Answer 1

Using the drag layer isn't going to work unless you are using an honest to goodness component for the ball. Your other option might be to try to use the glasspane, which is a pain in the neck, or a floating window component.
In any case,I built the code below for dragging Windows around in a frame. You're free to use it but please site me in your school or business work
package tjacobs.ui;
import java.awt.*;
import java.awt.event.*;
public abstract class WindowUtilities {
public static Point getBottomRightOfScreen(Component c) {
     Dimension scr_size = Toolkit.getDefaultToolkit().getScreenSize();
     Dimension c_size = c.getSize();
     return new Point(scr_size.width - c_size.width, scr_size.height - c_size.height);
     public static class Draggable extends MouseAdapter implements MouseMotionListener {
Point mLastPoint;
Window mWindow;
public Draggable(Window w) {
w.addMouseMotionListener(this);
w.addMouseListener(this);
mWindow = w;
public void mousePressed(MouseEvent me) {
mLastPoint = me.getPoint();
public void mouseReleased(MouseEvent me) {
mLastPoint = null;
public void mouseMoved(MouseEvent me) {}
public void mouseDragged(MouseEvent me) {
int x, y;
if (mLastPoint != null) {
x = mWindow.getX() + (me.getX() - (int)mLastPoint.getX());
y = mWindow.getY() + (me.getY() - (int)mLastPoint.getY());
mWindow.setLocation(x, y);
}