public void actionPerformed(ActionEvent event) {
   JTree tree = getTree();
   TreePath path = tree.getSelectionPath();
   if (path == null) {
     sheet.getLogger().warning("Warning: User must select a node to attach a new config to");
     // XXX add a message telling users to select a node
   } else {
     createAttrConfigForNode((Node) path.getLastPathComponent());
   }
 }
 public void actionPerformed(ActionEvent event) {
   JTree tree = getTree();
   TreePath path = tree.getSelectionPath();
   if (path == null) {
     sheet.getLogger().warning("Warning: User must select a node to delete");
     // XXX add message telling users to select a node
   } else {
     Node selected = (Node) path.getLastPathComponent();
     try {
       Node parent = selected.getParent();
       if (parent != null) {
         parent.removeChild(selected);
         select(parent);
       }
     } catch (UnsupportedOperationException uox) {
       sheet.getLogger().warning("Cannot delete node: " + selected);
     }
   }
 }