private void Init()
{
_mChildrenHeights = new SparseIntArray();
_mHeaderViewInfos = new List <FixedViewInfo>();
_mFooterViewInfos = new List <FixedViewInfo>();
base.SetClipChildren(false);
ScrollStateChanged += (sender, args) =>
{
if (_mOriginalScrollListener != null)
{
_mOriginalScrollListener.OnScrollStateChanged(args.View, args.ScrollState);
}
};
Scroll += (sender, args) =>
{
if (_mOriginalScrollListener != null)
{
_mOriginalScrollListener.OnScroll(args.View, args.FirstVisibleItem, args.VisibleItemCount, args.TotalItemCount);
}
// AbsListView#invokeOnItemScrollListener calls onScrollChanged(0, 0, 0, 0)
// on Android 4.0+, but Android 2.3 is not. (Android 3.0 is unknown)
// So call it with onScrollListener.
OnScrollChanged();
};
}
public override void OnScrolled(Android.Support.V7.Widget.RecyclerView recyclerView, int dx, int dy)
{
LinearLayoutManager layoutManager = (LinearLayoutManager)recyclerView.GetLayoutManager();
int firstVisible = layoutManager.FindFirstVisibleItemPosition();
int visibleCount = Math.Abs(firstVisible - layoutManager.FindLastCompletelyVisibleItemPosition());
int itemCount = recyclerView.GetAdapter().ItemCount;
if (firstVisible != _lastFirstVisible || visibleCount != _lastVisibleCount || itemCount != _lastItemCount)
{
_scrollListener.OnScroll(null, firstVisible, visibleCount, itemCount);
_lastVisibleCount = firstVisible;
_lastVisibleCount = visibleCount;
_lastItemCount = itemCount;
}
}