code: public void unregisterComponent(java.awt.Component c)
      {
          java.awt.dnd.DragGestureRecognizer recognizer = 
              (java.awt.dnd.DragGestureRecognizer)this.hmDragGestureRecognizers.remove(c);
          if (recognizer != null)
              recognizer.setComponent(null);
      }
docs: remove drag support from the given Component.
  @param c the Component to remove