Dragging a drawing when double-buffering

Question

Hopefully someone out there can help me with this...
To state the situation simply, I have an applet in which I need to select, drag, and drop in order to move them around. The applet works fine right now, but I can't figure out how to add dragging. The way I have it, you click the object, drag the mouse to where you want to move it, and let go. It then dissapears from where it was, and appears where it was placed. The prolem is that I want to actively see the object being dragged....even an outline would work. As it is, it's difficult to know what you were selecting to move.
I added a mouseDragged() function to the program, but I see no evidence of it working, which I think has something to do with the double-buffering I used. As far as I can tell, it does draw the object being dragged, it just doesn't ever show up on the screen....
I would appreciate any input anyone can offer!

Answer 1

With double buffering
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.awt.image.BufferedImage;
public class Omove extends Frame
     BufferedImage img;
     Graphics      mg;
     Vector  v  = new Vector();
     Mobject m;
     int    iv = -1;
     int    dx = -1;
     int    dy = -1;
public Omove()
     addWindowListener(new WindowAdapter()
    {     public void windowClosing(WindowEvent ev)
          {     dispose();
               System.exit(0);}});
     setBounds(10,10,400,300);
     v.add(new Mobject(1,30,30));
     v.add(new Mobject(1,89,120));
     v.add(new Mobject(2,130,230));
     v.add(new Mobject(3,210,60));
     addMouseListener(new MouseAdapter()     
     {     public void mouseReleased(MouseEvent m)
               if (iv != -1) putTheObject(m.getX(),m.getY());               
     addMouseMotionListener(new MouseMotionAdapter()          
          {     public void mouseDragged(MouseEvent m)
                    if (dx == -1) findTheObject(m.getX(),m.getY());     
                    if (iv != -1)
                         dx = m.getX();     
                         dy = m.getY();
                         repaint();
     setVisible(true);
private void findTheObject(int x, int y)
     for (int i=0; i < v.size(); i++)
          m = (Mobject)v.get(i);
          if (x >= m.x && y >= m.y && x <= m.x+30 && y <= m.y+30)
               iv = i;
private void putTheObject(int x,int y)
     iv = -1;
     dx = -1;
public void paint(Graphics g)
     if (img == null)
          img = (BufferedImage)this.createImage(getWidth(),getHeight());
          mg  = img.getGraphics();
     mg.setColor(Color.white);
     mg.fillRect(0,0,getWidth(),getHeight());
     for (int i=0; i < v.size(); i++)
          m = (Mobject)v.get(i);
          if (iv == i)           
               m.x = dx;
               m.y = dy;
          m.draw(mg);
     g.drawImage(img,0,0,null);
public void update(Graphics g)
     paint(g);
public class Mobject
     int x,y,t;
public Mobject(int t, int x, int y)
     this.t = t;     
     this.x = x;     
     this.y = y;     
public void draw(Graphics g)
     if (t == 1)
          g.setColor(Color.red);
          g.fillRect(x,y,30,30);
     if (t == 2)
          g.setColor(Color.orange);
          g.fillOval(x,y,30,30);
     if (t == 3)
          g.setColor(Color.blue);
          g.fillOval(x,y,50,30);
public static void main (String[] args)
     new Omove();
Noah