private void initUI() {
    myTree.setShowsRootHandles(true);
    myTree.setRootVisible(false);
    myTree.setRowHeight(0); // enable variable-height rows
    myTree.setCellRenderer(new TodoCompositeRenderer());
    EditSourceOnDoubleClickHandler.install(myTree);
    EditSourceOnEnterKeyHandler.install(myTree);
    TreeUIHelper.getInstance().installTreeSpeedSearch(myTree);

    DefaultActionGroup group = new DefaultActionGroup();
    group.add(ActionManager.getInstance().getAction(IdeActions.ACTION_EDIT_SOURCE));
    group.addSeparator();
    group.add(CommonActionsManager.getInstance().createExpandAllAction(myTreeExpander, this));
    group.add(CommonActionsManager.getInstance().createCollapseAllAction(myTreeExpander, this));
    group.addSeparator();
    group.add(ActionManager.getInstance().getAction(IdeActions.GROUP_VERSION_CONTROLS));
    PopupHandler.installPopupMenu(myTree, group, ActionPlaces.TODO_VIEW_POPUP);

    myUsagePreviewPanel.setVisible(mySettings.showPreview);

    setContent(createCenterComponent());

    myTree.getSelectionModel().addTreeSelectionListener(new TreeSelectionListener() {
      @Override
      public void valueChanged(@NotNull TreeSelectionEvent e) {
        myCoroutineHelper.schedulePreviewPanelLayoutUpdate();
      }
    });

    myAutoScrollToSourceHandler = new MyAutoScrollToSourceHandler();
    myAutoScrollToSourceHandler.install(myTree);

    // Create tool bars and register custom shortcuts

    DefaultActionGroup toolbarGroup = new DefaultActionGroup();
    toolbarGroup.add(new PreviousOccurenceToolbarAction(myOccurenceNavigator));
    toolbarGroup.add(new NextOccurenceToolbarAction(myOccurenceNavigator));
    toolbarGroup.add(new SetTodoFilterAction(myProject, mySettings, todoFilter -> setTodoFilter(todoFilter)));
    toolbarGroup.add(createAutoScrollToSourceAction());
    toolbarGroup.add(CommonActionsManager.getInstance().createExpandAllAction(myTreeExpander, this));
    toolbarGroup.add(CommonActionsManager.getInstance().createCollapseAllAction(myTreeExpander, this));

    if (!myCurrentFileMode) {
      DefaultActionGroup groupBy = createGroupByActionGroup();
      toolbarGroup.add(groupBy);
    }

    toolbarGroup.add(new MyPreviewAction());

    ActionToolbar toolbar = ActionManager.getInstance().createActionToolbar(ActionPlaces.TODO_VIEW_TOOLBAR, toolbarGroup, false);
    toolbar.setTargetComponent(myTree);
    setToolbar(toolbar.getComponent());
  }
private void initUI()