public void setTargetEditor(MiEditor editor) {
   if (mouseLocationEditor != null) {
     mouseLocationEditor.removeEventHandler(mouseLocationMonitor);
   }
   mouseLocationEditor = editor;
   mouseLocationMonitor =
       new MiMouseLocationDisplayMonitor(getField(X_FIELD_INDEX), getField(Y_FIELD_INDEX));
   mouseLocationEditor.appendEventHandler(mouseLocationMonitor);
 }
 public void deleteSelf() {
   if (mouseLocationEditor != null) mouseLocationEditor.removeEventHandler(mouseLocationMonitor);
   super.deleteSelf();
 }