// Used by the renderer to maintain scroll offset when using ItemsUpdatingScrollMode KeepScrollOffset
public void UndoNextScrollAdjustment()
{
// Don't start tracking the scroll offsets until we really need to
if (!_maintainingScrollOffsets)
{
_maintainingScrollOffsets = true;
_recyclerView.AddOnScrollListener(this);
}
_undoNextScrollAdjustment = true;
_lastScrollX = _recyclerView.ComputeHorizontalScrollOffset();
_lastScrollY = _recyclerView.ComputeVerticalScrollOffset();
}
public void CenterIfNeeded(RecyclerView recyclerView, bool isHorizontal)
{
if (!(recyclerView.GetLayoutManager() is LinearLayoutManager linearLayoutManager))
{
return;
}
var itemSourceCount = _itemsSource.Count;
var firstCompletelyItemVisible = linearLayoutManager.FindFirstCompletelyVisibleItemPosition();
var offSet = recyclerView.ComputeHorizontalScrollOffset();
if (!isHorizontal)
{
offSet = recyclerView.ComputeVerticalScrollOffset();
}
if (firstCompletelyItemVisible == 0)
{
linearLayoutManager.ScrollToPositionWithOffset(itemSourceCount, -offSet);
}
}