private void updateActionModeTitle() {
    String title =
        adapter.getAmountOfCheckedItems()
            + " "
            + getActivity()
                .getResources()
                .getQuantityString(
                    R.plurals.formula_editor_variable_context_action_item_selected,
                    adapter.getAmountOfCheckedItems());

    contextActionMode.setTitle(title);
  }
  @Override
  public void onCheckedChange() {
    if (!inContextMode) {
      return;
    }

    updateActionModeTitle();
    Utils.setSelectAllActionModeButtonVisibility(
        selectAllActionModeButton,
        adapter.getCount() > 0 && adapter.getAmountOfCheckedItems() != adapter.getCount());
  }