code: public int getAcceptableActions(Component c)
      {
          if (c instanceof javax.swing.JTree 
              && ((javax.swing.JTree)c).getModel() instanceof OjbMetaDataTreeModel)
              return DnDWorkerConstants.DRAG_COPY | DnDWorkerConstants.DRAG_LINK;
          else return DnDWorkerConstants.NONE;
      }
docs: Return a bitmask of acceptable actions. In most cases you will only support
  DRAG_COPY, but sometimes you might support DRAG_LINK or DRAG_MOVE as well.
  @param c The component that acts as the drag source
  @return A bitmask of possible drag actions for the given Component