private void OnLongPressGestureDetected(object source, LongPressGestureDetector.DetectedEventArgs e) { switch (e.LongPressGesture.State) { case Gesture.StateType.Started: { Size windowSize = NUIApplication.GetDefaultWindow().Size; ItemRange range = new ItemRange(0, 0); mItemView.GetItemsRange(range); uint item = (e.LongPressGesture.ScreenPoint.Y < 0.5f * (float)windowSize.Height) ? range.begin : range.end; mItemView.ScrollToItem(item, SCROLL_TO_ITEM_ANIMATION_TIME); break; } case Gesture.StateType.Finished: { PropertyMap attributes = new PropertyMap(); mItemView.DoAction("stopScrolling", attributes); break; } default: { break; } } }