did_drag_end_step3.dart

  bool _didDragEnd(ScrollNotification notification) {
    // Whenever dragDetails are null the scrolling happends without the users input
    // meaning that the user release the finger --> drag has ended.
    // For Cupertino Scrollables the ScrollEndNotification can not be used
    // since it will be send after the list scroll has completely ended and
    // the list is in its initial state
    if (notification is ScrollUpdateNotification &&
        notification.dragDetails == null) {
      return true;
    }

    // For Material Scrollables we can simply use the ScrollEndNotification
    if (notification is ScrollEndNotification) {
      return true;
    }

    return false;
  }