public void notifyGroupChanged(String groupId) {
    // Clear cache
    groupTable.removeAllItems();
    groupListContainer.removeAllItems();

    // select changed group
    groupTable.select(groupListContainer.getIndexForObjectId(groupId));
  }
  @Override
  protected void initUi() {
    super.initUi();

    if (groupId == null) {
      selectElement(0);
    } else {
      selectElement(groupListContainer.getIndexForObjectId(groupId));
    }
  }