private void applyItemTypeMutators(Array<String> actionsSet) {
    // generic mutators
    if (sandbox.getSelector().getCurrentSelection().size() == 1) {
      if (sandbox.getSelector().selectionIsComposite()) {
        actionsSet.add(Sandbox.SHOW_ADD_LIBRARY_DIALOG);
        actionsSet.add(Sandbox.ACTION_CAMERA_CHANGE_COMPOSITE);
      }
      actionsSet.add(Sandbox.ACTION_SET_GRID_SIZE_FROM_ITEM);
    }

    // external plugin mutators
    PluginManager pluginManager = facade.retrieveProxy(PluginManager.NAME);
    pluginManager.dropDownActionSets(sandbox.getSelector().getCurrentSelection(), actionsSet);
  }
  @Override
  public void handleNotification(Notification notification) {
    super.handleNotification(notification);

    switch (notification.getName()) {
      case Overlap2D.SCENE_RIGHT_CLICK:
        Vector2 stageCoords = notification.getBody();
        showPopup(SCENE_ACTIONS_SET, stageCoords);
        break;
      case Overlap2D.ITEM_RIGHT_CLICK:
        Array<String> actionsSet = new Array<>(actionSets.get(ITEMS_ACTIONS_SET));
        applyItemTypeMutators(actionsSet);
        showPopup(actionsSet, sandbox.getSelector().getSelectedItem());
        break;
      case UIResourcesBoxMediator.IMAGE_RIGHT_CLICK:
        showPopup(IMAGE_RESOURCE_ACTION_SET, notification.getBody());
        break;
      case UIResourcesBoxMediator.ANIMATION_RIGHT_CLICK:
        showPopup(RESOURCE_ACTION_SET, notification.getBody());
        break;
      case UIResourcesBoxMediator.LIBRARY_ITEM_RIGHT_CLICK:
        showPopup(RESOURCE_ACTION_SET, notification.getBody());
        break;
      case UIResourcesBoxMediator.PARTICLE_EFFECT_RIGHT_CLICK:
        showPopup(RESOURCE_ACTION_SET, notification.getBody());
        break;
      case UIDropDownMenu.ITEM_CLICKED:
        facade.sendNotification(notification.getBody(), currentObservable);
        break;
      default:
        break;
    }
  }