Java Mouse Motion Listener

I think I found a major problem with Java's event handler but I need to make sure its not just a mistake I've made.

Im getting this error ever time a mouse motion event occurs after the program has been running for about 30 seconds. 

at java.awt.AWTEventMulticaster.mouseMoved(Unknown Source)

Here is my source code:


import java.awt.*; // Use graphics
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.applet.*; // Use applets
import javax.swing.*; // Use swing stuff (GUI)
import java.util.*; // Use util
public class Cube extends JApplet
{
    public void init()
    {
         setSize(640,480);
         getContentPane().add(new CubePanel());
        
    }
   
    public class CubePanel extends JPanel implements MouseMotionListener
     {
          private double x_verts[] = {-50,50,50,-50}; // Four vertices for a cube
          private double y_verts[] = {50,50,-50,-50};
          private double shape_save[] = {-50,50,50,-50,50,50,-50,-50}; // Original shape before transformation
          private double rotation_pos = 0; // Rotation position
          double xTransform = 100;
          double yTransform = 10;
          int yMouse = 128;
          int xMouse = 128;
          Color[] cIndex = {Color.yellow, Color.red, Color.blue, Color.green};
         
         
          void CubePanel()
          {
             
          }
          private void drawCube(Graphics page,int xpos,int ypos)
          {
               // Reset to original shape
               for(int index = 0;index < 4;index++)
                    x_verts[index] = shape_save[index]; // Copy X's
               for(int index = 4;index < 8;index++)
                    y_verts[index-4] = shape_save[index]; // Copy Y's
               // Rotate all the points like so...
               double temp_x,temp_y;
               for(int index = 0;index < 4;index++)
               {
                    // Rotate the square normally over the y axis in the xyz plane (I think)
                    temp_x = x_verts[index]*Math.cos(rotation_pos) - y_verts[index]*Math.sin(rotation_pos);
                    temp_y = x_verts[index]*Math.sin(rotation_pos) + y_verts[index]*Math.cos(rotation_pos);
                    x_verts[index] = temp_x + xTransform;
                    y_verts[index] = temp_y;
                    // And the square rotates to look 3D 2x along the x axis in the xyz plane (I think)
                    y_verts[index] = y_verts[index]*Math.sin(rotation_pos/2) + yTransform;
                    //xTransform -= .001;
                    //yTransform -= .001;
               }
               // Add a degree of rotation
               rotation_pos += 0.01;
              
               page.setColor(Color.blue);
               for(int index = 0;index < 4;index++)
               {
                   page.setColor(cIndex[index]);
                   if(index < 3)
                    {
                         page.drawLine((int)x_verts[index]+xpos,(int)y_verts[index]+ypos,(int)x_verts[index+1]+xpos,(int)y_verts[index+1]+ypos);
                    }
                    else
                    {
                         page.drawLine((int)x_verts[index]+xpos,(int)y_verts[index]+ypos,(int)x_verts[0]+xpos,(int)y_verts[0]+ypos);
                    }
               }
          }
          public void paintComponent(Graphics page)
          {
              addMouseMotionListener(this);
               super.paintComponent(page);
               // Use a black background
               setBackground(Color.black);
              
               // Draw the cube
               drawCube(page,xMouse,yMouse);
              
               repaint();
          }
        @Override
        public void mouseDragged(MouseEvent me) {
            xMouse = me.getX() - 95;
            yMouse = me.getY();   
        }
        @Override
        public void mouseMoved(MouseEvent me) {
           
           
        }
     }
    
}

No, the major problem is contained within the first word of your post subject.

I think its just Java

>>1
You should call addMouseMotionListener once in the constructor.

I HELPED HIM!

Why did you put addMouseMotionListener(this); in the paintComponent(Graphics g) method of the nested CubePanel class?  Every time you have a paint event you register another copy of this MouseMotionListener to the project; all you need to do is add it once, somewhere that only gets executed once.

Also, you don't need to Override mouseMoved() and mouseDragged(); you're implementing them.  Rather, you should Override the CubePanel's paintComponent(Graphics g) method.  You may want to call super(); in the constructor for CubePanel to call JPanel's constructor, but that may be counterintuitive to what you're doing.

>>4
>>5
Ahh yes this was my problem thanks guys.

>>2
>>3
Ahh yes this was my problem thanks guys.

>>6-7
I find your lack of optimized quotes disturbing.

Java
Ahh yes this was my problem [spoiler]_{and now I have 2 problems}

11 Name: Anonymous 2011-02-17 19:39

check my doubles

Don't change these.

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