/** This is called to transfer the data. */
 public void dragSetData(DragSourceEvent event) {
   if (LocalTransfer.getInstance().isSupportedType(event.dataType)) {
     event.data = selection;
   }
 }
 /** This is called when dragging is completed; it forgets the {@link #selection}. */
 public void dragFinished(DragSourceEvent event) {
   selection = null;
   LocalTransfer.getInstance().javaToNative(null, null);
 }