code: public void registerComponent(java.awt.Component c)
      {
          unregisterComponent(c);
          if (recognizerAbstractClass == null)
          {
              hmDragGestureRecognizers.put(c,  
                  dragSource.createDefaultDragGestureRecognizer(c, 
                      dragWorker.getAcceptableActions(c), dgListener)
                                          );
          }
          else
          {
              hmDragGestureRecognizers.put(c, 
                  dragSource.createDragGestureRecognizer (recognizerAbstractClass,
                      c, dragWorker.getAcceptableActions(c), dgListener)
                                          );
          }
      }
docs: add a Component to this Worker. After the call dragging is enabled for this
  Component.
  @param c the Component to register