Porting some animation-related fixes from StickyHeaderDecoration to DoubleHeaderDecoration.
Additional fixes to DoubleHeaderDecoration to handle smooth scrolling (i.e. LinearLayoutManager.scrollToPositionWithOffset); mostly filtering-out invisible children off the top of the parent RecyclerView that exist in this situation.
Porting some animation-related fixes from StickyHeaderDecoration to DoubleHeaderDecoration. Additional fixes to DoubleHeaderDecoration to handle smooth scrolling (i.e. LinearLayoutManager.scrollToPositionWithOffset); mostly filtering-out invisible children off the top of the parent RecyclerView that exist in this situation.