//Arbitrarily define a 5-pixel shift as the
//official beginning of a drag.
if ((( dx > 5 ) || ( dy > 5 )) && dockable.canDrag ) {
//This is a drag, not a click.
JComponent c = (JComponent)e.getSource();
TransferHandler handler = c.getTransferHandler();
//Tell the transfer handler to initiate the drag.
handler.exportAsDrag( c, firstMouseEvent, action );
firstMouseEvent = null;
glassPane = (Container)getRootPane().getGlassPane();
glassPane.setVisible( true );
dockable.dockedContainer.addDragProxies( glassPane );