public static boolean hasReadOnlyUsages(final Collection<Usage> usages) {
    for (Usage usage : usages) {
      if (usage.isReadOnly()) return true;
    }

    return false;
  }
 @Override
 protected String getElementText(@NotNull Object element) {
   if (!(element instanceof UsageNode)) return element.toString();
   UsageNode node = (UsageNode) element;
   if (node instanceof StringNode) return "";
   Usage usage = node.getUsage();
   if (usage == MORE_USAGES_SEPARATOR) return "";
   GroupNode group = (GroupNode) node.getParent();
   return usage.getPresentation().getPlainText() + group;
 }
 @NotNull
 private Set<Usage> getReadOnlyUsages() {
   final Set<Usage> result = new THashSet<Usage>();
   final Set<Map.Entry<Usage, UsageNode>> usages = myUsageNodes.entrySet();
   for (Map.Entry<Usage, UsageNode> entry : usages) {
     Usage usage = entry.getKey();
     UsageNode node = entry.getValue();
     if (node != null && node != NULL_NODE && !node.isExcluded() && usage.isReadOnly()) {
       result.add(usage);
     }
   }
   return result;
 }
        @Override
        public int compare(UsageNode c1, UsageNode c2) {
          if (c1 instanceof StringNode) return 1;
          if (c2 instanceof StringNode) return -1;
          Usage o1 = c1.getUsage();
          Usage o2 = c2.getUsage();
          if (o1 == MORE_USAGES_SEPARATOR) return 1;
          if (o2 == MORE_USAGES_SEPARATOR) return -1;

          VirtualFile v1 = UsageListCellRenderer.getVirtualFile(o1);
          VirtualFile v2 = UsageListCellRenderer.getVirtualFile(o2);
          String name1 = v1 == null ? null : v1.getName();
          String name2 = v2 == null ? null : v2.getName();
          int i = Comparing.compare(name1, name2);
          if (i != 0) return i;

          if (o1 instanceof Comparable && o2 instanceof Comparable) {
            return ((Comparable) o1).compareTo(o2);
          }

          FileEditorLocation loc1 = o1.getLocation();
          FileEditorLocation loc2 = o2.getLocation();
          return Comparing.compare(loc1, loc2);
        }
 private void navigateAndHint(
     @NotNull Usage usage,
     @Nullable final String hint,
     @NotNull final FindUsagesHandler handler,
     @NotNull final RelativePoint popupPosition,
     final int maxUsages,
     @NotNull final FindUsagesOptions options) {
   usage.navigate(true);
   if (hint == null) return;
   final Editor newEditor = getEditorFor(usage);
   if (newEditor == null) return;
   final Project project = handler.getProject();
   // opening editor is performing in invokeLater
   IdeFocusManager.getInstance(project)
       .doWhenFocusSettlesDown(
           new Runnable() {
             @Override
             public void run() {
               newEditor
                   .getScrollingModel()
                   .runActionOnScrollingFinished(
                       new Runnable() {
                         @Override
                         public void run() {
                           // after new editor created, some editor resizing events are still
                           // bubbling. To prevent hiding hint, invokeLater this
                           IdeFocusManager.getInstance(project)
                               .doWhenFocusSettlesDown(
                                   new Runnable() {
                                     @Override
                                     public void run() {
                                       if (newEditor.getComponent().isShowing()) {
                                         showHint(
                                             hint,
                                             newEditor,
                                             popupPosition,
                                             handler,
                                             maxUsages,
                                             options);
                                       }
                                     }
                                   });
                         }
                       });
             }
           });
 }
 public UsageNode doAppendUsage(@NotNull Usage usage) {
   // invoke in ReadAction to be be sure that usages are not invalidated while the tree is being
   // built
   ApplicationManager.getApplication().assertReadAccessAllowed();
   if (!usage.isValid()) {
     // because the view is built incrementally, the usage may be already invalid, so need to
     // filter such cases
     return null;
   }
   UsageNode node = myBuilder.appendUsage(usage);
   myUsageNodes.put(usage, node == null ? NULL_NODE : node);
   if (!myIsFirstVisibleUsageFound && node != null) { // first visible usage found;
     myIsFirstVisibleUsageFound = true;
     showNode(node);
   }
   return node;
 }
 @Nullable
 private static Editor getEditorFor(@NotNull Usage usage) {
   FileEditorLocation location = usage.getLocation();
   FileEditor newFileEditor = location == null ? null : location.getEditor();
   return newFileEditor instanceof TextEditor ? ((TextEditor) newFileEditor).getEditor() : null;
 }