It is easy to determine what node has been selected in a JTree, but I
cannot determine when a node is not being selected.  For example, if
the user clicks in the white space outside a JTree, every node on the
tree should be deselected.  I know the JTree has a clearSelection()
method, but I can't figure out how to determine whether the user
clicked in the white space or on a node.

Any help would be much appreciated.  Thanks.