128a129,149
>     /**
>      * Listener for mouse clicks.
>      */
>     private MouseListener mouseListener;
>     
>     /**
>      * Listener for mouse movements.
>      */
>     private MouseMotionListener motionListener;
>     
>     /**
>      * Listener for the keyboard.
>      */
>     private KeyListener keyListener;
> 
>     /**
>      * Reflects whether the drawing view is in read-only mode (from a user's
>      * perspective).
>      */
>     private boolean readOnly;
> 
168,168c189,189
< 		return new DrawingViewMouseListener();
---
>         mouseListener = new DrawingViewMouseListener();
168a190,190
> 		return mouseListener;
172,172c194,194
< 		return  new DrawingViewMouseMotionListener();
---
>         motionListener = new DrawingViewMouseMotionListener();
172a195,195
> 		return  motionListener;
176a200,200
> 		return keyListener;
176,176c199,199
< 		return new DrawingViewKeyListener();
---
>         keyListener = new DrawingViewKeyListener();
1095a1120,1150
>      * Asks whether the drawing view is in read-only mode. If so, the user can't
>      * modify it using mouse or keyboard actions. Yet, it can still be modified
>      * from inside the program.
>      */
>     public boolean getReadOnly() {
>         return readOnly;
>     }
>     
>     /**
>      * Determines whether the drawing view is in read-only mode. If so, the user can't
>      * modify it using mouse or keyboard actions. Yet, it can still be modified
>      * from inside the program.
>      */
>     public void setReadOnly(boolean readOnly) {
>         if (readOnly != this.readOnly) {
>             if (readOnly) {
>                 removeMouseListener(mouseListener);
>                 removeMouseMotionListener(motionListener);
>                 removeKeyListener(keyListener);
>             }
>             else {
>                 addMouseListener(mouseListener);
>                 addMouseMotionListener(motionListener);
>                 addKeyListener(keyListener);
>             }
>             
>             this.readOnly = readOnly;
>         }
>     }
> 
> 	/**