/** Instantiates a new base viewer activity. */
  public ViewerActivityController(final ViewerActivity activity) {
    super(activity, BEFORE_CREATE, BEFORE_RECREATE, AFTER_CREATE, ON_POST_CREATE, ON_DESTROY);

    intent = activity.getIntent();

    history = new NavigationHistory(this);

    executor = new AsyncTaskExecutor(256, 1, 5, 1, "BookExecutor-" + id);

    SettingsManager.addListener(this);
  }