public void restore() {
   final UsageNode node = myUsageNodes.get(myUsage);
   if (node == NULL_NODE || node == null) {
     return;
   }
   final DefaultMutableTreeNode parentGroupingNode = (DefaultMutableTreeNode) node.getParent();
   if (parentGroupingNode != null) {
     final TreePath treePath = new TreePath(parentGroupingNode.getPath());
     myTree.expandPath(treePath);
     if (mySelected) {
       myTree.addSelectionPath(treePath.pathByAddingChild(node));
     }
   }
 }
 private void restoreUsageExpandState(final Collection<UsageState> states) {
   // always expand the last level group
   final DefaultMutableTreeNode root = (DefaultMutableTreeNode) myTree.getModel().getRoot();
   for (int i = root.getChildCount() - 1; i >= 0; i--) {
     final DefaultMutableTreeNode child = (DefaultMutableTreeNode) root.getChildAt(i);
     if (child instanceof GroupNode) {
       final TreePath treePath = new TreePath(child.getPath());
       myTree.expandPath(treePath);
     }
   }
   myTree.getSelectionModel().clearSelection();
   for (final UsageState usageState : states) {
     usageState.restore();
   }
 }
 private void checkNodeValidity(@NotNull DefaultMutableTreeNode node) {
   Enumeration enumeration = node.children();
   while (enumeration.hasMoreElements()) {
     checkNodeValidity((DefaultMutableTreeNode) enumeration.nextElement());
   }
   if (node instanceof Node && node != getModelRoot()) ((Node) node).update(this);
 }
 @Nullable
 private static Navigatable getNavigatableForNode(@NotNull DefaultMutableTreeNode node) {
   Object userObject = node.getUserObject();
   if (userObject instanceof Navigatable) {
     final Navigatable navigatable = (Navigatable) userObject;
     return navigatable.canNavigate() ? navigatable : null;
   }
   return null;
 }
 private void captureUsagesExpandState(TreePath pathFrom, final Collection<UsageState> states) {
   if (!myTree.isExpanded(pathFrom)) {
     return;
   }
   final DefaultMutableTreeNode node = (DefaultMutableTreeNode) pathFrom.getLastPathComponent();
   final int childCount = node.getChildCount();
   for (int idx = 0; idx < childCount; idx++) {
     final TreeNode child = node.getChildAt(idx);
     if (child instanceof UsageNode) {
       final Usage usage = ((UsageNode) child).getUsage();
       states.add(
           new UsageState(
               usage,
               myTree.getSelectionModel().isPathSelected(pathFrom.pathByAddingChild(child))));
     } else {
       captureUsagesExpandState(pathFrom.pathByAddingChild(child), states);
     }
   }
 }
  private static void collectUsages(
      @NotNull DefaultMutableTreeNode node, @NotNull Set<Usage> usages) {
    if (node instanceof UsageNode) {
      UsageNode usageNode = (UsageNode) node;
      final Usage usage = usageNode.getUsage();
      usages.add(usage);
    }

    Enumeration enumeration = node.children();
    while (enumeration.hasMoreElements()) {
      DefaultMutableTreeNode child = (DefaultMutableTreeNode) enumeration.nextElement();
      collectUsages(child, usages);
    }
  }