public void CollapseLevels(MotionEvent ev)
        {
            if (bsb.State == BottomSheetBehavior.StateExpanded)
            {
                Rect outRect = new Rect();
                flSheet.GetGlobalVisibleRect(outRect);

                if (!outRect.Contains((int)ev.RawX, (int)ev.RawY))
                {
                    bsb.State = BottomSheetBehavior.StateCollapsed;
                }
            }
        }