public Object getData(String dataId) {
    if (PlatformDataKeys.PROJECT.is(dataId)) {
      return myProject;
    }
    if (PlatformDataKeys.NAVIGATABLE.is(dataId)) {
      final FavoritesTreeNodeDescriptor[] selectedNodeDescriptors = getSelectedNodeDescriptors();
      return selectedNodeDescriptors.length == 1 ? selectedNodeDescriptors[0].getElement() : null;
    }
    if (PlatformDataKeys.NAVIGATABLE_ARRAY.is(dataId)) {
      final List<Navigatable> selectedElements = getSelectedElements(Navigatable.class);
      return selectedElements.toArray(new Navigatable[selectedElements.size()]);
    }

    if (PlatformDataKeys.CUT_PROVIDER.is(dataId)) {
      return myCopyPasteDelegator.getCutProvider();
    }
    if (PlatformDataKeys.COPY_PROVIDER.is(dataId)) {
      return myCopyPasteDelegator.getCopyProvider();
    }
    if (PlatformDataKeys.PASTE_PROVIDER.is(dataId)) {
      return myCopyPasteDelegator.getPasteProvider();
    }
    if (PlatformDataKeys.HELP_ID.is(dataId)) {
      return myHelpId;
    }
    if (LangDataKeys.PSI_ELEMENT.is(dataId)) {
      PsiElement[] elements = getSelectedPsiElements();
      if (elements.length != 1) {
        return null;
      }
      return elements[0] != null && elements[0].isValid() ? elements[0] : null;
    }
    if (LangDataKeys.PSI_ELEMENT_ARRAY.is(dataId)) {
      final PsiElement[] elements = getSelectedPsiElements();
      ArrayList<PsiElement> result = new ArrayList<PsiElement>();
      for (PsiElement element : elements) {
        if (element.isValid()) {
          result.add(element);
        }
      }
      return result.isEmpty() ? null : result.toArray(new PsiElement[result.size()]);
    }

    if (LangDataKeys.IDE_VIEW.is(dataId)) {
      return myIdeView;
    }

    if (LangDataKeys.TARGET_PSI_ELEMENT.is(dataId)) {
      return null;
    }

    if (LangDataKeys.MODULE_CONTEXT.is(dataId)) {
      Module[] selected = getSelectedModules();
      return selected != null && selected.length == 1 ? selected[0] : null;
    }
    if (LangDataKeys.MODULE_CONTEXT_ARRAY.is(dataId)) {
      return getSelectedModules();
    }

    if (PlatformDataKeys.DELETE_ELEMENT_PROVIDER.is(dataId)) {
      final Object[] elements = getSelectedNodeElements();
      return elements != null && elements.length >= 1 && elements[0] instanceof Module
          ? myDeleteModuleProvider
          : myDeletePSIElementProvider;
    }
    if (ModuleGroup.ARRAY_DATA_KEY.is(dataId)) {
      final List<ModuleGroup> selectedElements = getSelectedElements(ModuleGroup.class);
      return selectedElements.isEmpty()
          ? null
          : selectedElements.toArray(new ModuleGroup[selectedElements.size()]);
    }
    if (LibraryGroupElement.ARRAY_DATA_KEY.is(dataId)) {
      final List<LibraryGroupElement> selectedElements =
          getSelectedElements(LibraryGroupElement.class);
      return selectedElements.isEmpty()
          ? null
          : selectedElements.toArray(new LibraryGroupElement[selectedElements.size()]);
    }
    if (NamedLibraryElement.ARRAY_DATA_KEY.is(dataId)) {
      final List<NamedLibraryElement> selectedElements =
          getSelectedElements(NamedLibraryElement.class);
      return selectedElements.isEmpty()
          ? null
          : selectedElements.toArray(new NamedLibraryElement[selectedElements.size()]);
    }
    if (CONTEXT_FAVORITES_ROOTS_DATA_KEY.is(dataId)) {
      List<FavoritesTreeNodeDescriptor> result = new ArrayList<FavoritesTreeNodeDescriptor>();
      FavoritesTreeNodeDescriptor[] selectedNodeDescriptors = getSelectedNodeDescriptors();
      for (FavoritesTreeNodeDescriptor selectedNodeDescriptor : selectedNodeDescriptors) {
        FavoritesTreeNodeDescriptor root = selectedNodeDescriptor.getFavoritesRoot();
        if (root != null && !(root.getElement().getValue() instanceof String)) {
          result.add(root);
        }
      }
      return result.toArray(new FavoritesTreeNodeDescriptor[result.size()]);
    }
    if (FAVORITES_LIST_NAME_DATA_KEY.is(dataId)) {
      return myListName;
    }
    FavoritesTreeNodeDescriptor[] descriptors = getSelectedNodeDescriptors();
    if (descriptors.length > 0) {
      List<AbstractTreeNode> nodes = new ArrayList<AbstractTreeNode>();
      for (FavoritesTreeNodeDescriptor descriptor : descriptors) {
        nodes.add(descriptor.getElement());
      }
      return myFavoritesTreeStructure.getDataFromProviders(nodes, dataId);
    }
    return null;
  }
  public FavoritesTreeViewPanel(Project project, String helpId, String name) {
    super(new BorderLayout());
    myProject = project;
    myHelpId = helpId;
    myListName = name;

    myFavoritesTreeStructure = new FavoritesTreeStructure(project, myListName);
    DefaultMutableTreeNode root = new DefaultMutableTreeNode();
    root.setUserObject(myFavoritesTreeStructure.getRootElement());
    final DefaultTreeModel treeModel = new DefaultTreeModel(root);
    myTree = new DnDAwareTree(treeModel);
    myBuilder =
        new FavoritesViewTreeBuilder(
            myProject, myTree, treeModel, myFavoritesTreeStructure, myListName);

    TreeUtil.installActions(myTree);
    UIUtil.setLineStyleAngled(myTree);
    myTree.setRootVisible(false);
    myTree.setShowsRootHandles(true);
    myTree.setLargeModel(true);
    new TreeSpeedSearch(myTree);
    ToolTipManager.sharedInstance().registerComponent(myTree);
    myTree.setCellRenderer(
        new NodeRenderer() {
          public void customizeCellRenderer(
              JTree tree,
              Object value,
              boolean selected,
              boolean expanded,
              boolean leaf,
              int row,
              boolean hasFocus) {
            super.customizeCellRenderer(tree, value, selected, expanded, leaf, row, hasFocus);
            if (value instanceof DefaultMutableTreeNode) {
              final DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
              // only favorites roots to explain
              final Object userObject = node.getUserObject();
              if (userObject instanceof FavoritesTreeNodeDescriptor) {
                final FavoritesTreeNodeDescriptor favoritesTreeNodeDescriptor =
                    (FavoritesTreeNodeDescriptor) userObject;
                AbstractTreeNode treeNode = favoritesTreeNodeDescriptor.getElement();
                final ItemPresentation presentation = treeNode.getPresentation();
                String locationString = presentation.getLocationString();
                if (locationString != null && locationString.length() > 0) {
                  append(" (" + locationString + ")", SimpleTextAttributes.GRAY_ATTRIBUTES);
                } else if (node.getParent() != null && node.getParent().getParent() == null) {
                  final String location = favoritesTreeNodeDescriptor.getLocation();
                  if (location != null && location.length() > 0) {
                    append(" (" + location + ")", SimpleTextAttributes.GRAY_ATTRIBUTES);
                  }
                }
              }
            }
          }
        });
    JScrollPane scrollPane = ScrollPaneFactory.createScrollPane(myTree);
    myTreePopupHandler =
        CustomizationUtil.installPopupHandler(
            myTree, IdeActions.GROUP_FAVORITES_VIEW_POPUP, ActionPlaces.FAVORITES_VIEW_POPUP);
    add(scrollPane, BorderLayout.CENTER);
    // add(createActionsToolbar(), BorderLayout.NORTH);

    EditSourceOnDoubleClickHandler.install(myTree);
    EditSourceOnEnterKeyHandler.install(myTree);
    myCopyPasteDelegator =
        new CopyPasteDelegator(myProject, this) {
          @NotNull
          protected PsiElement[] getSelectedElements() {
            return getSelectedPsiElements();
          }
        };
  }