Cheesebaron.SlidingUpPanel.SlidingUpPanelLayout.UpdateObscuredViewVisibility C# (CSharp) Method

        private void UpdateObscuredViewVisibility()
        {
            if (ChildCount == 0) return;

            var leftBound = PaddingLeft;
            var rightBound = Width - PaddingLeft;
            var topBound = PaddingTop;
            var bottomBound = Height - PaddingBottom;
            int left;
            int right;
            int top;
            int bottom;

            if (_slideableView != null && HasOpaqueBackground(_slideableView))
            {
                left = _slideableView.Left;
                right = _slideableView.Right;
                top = _slideableView.Top;
                bottom = _slideableView.Bottom;
            }
            else
                left = right = top = bottom = 0;

            var child = GetChildAt(0);
            var clampedChildLeft = Math.Max(leftBound, child.Left);
            var clampedChildTop = Math.Max(topBound, child.Top);
            var clampedChildRight = Math.Max(rightBound, child.Right);
            var clampedChildBottom = Math.Max(bottomBound, child.Bottom);
            ViewStates vis;
            if (clampedChildLeft >= left && clampedChildTop >= top &&
                clampedChildRight <= right && clampedChildBottom <= bottom)
                vis = ViewStates.Invisible;
            else
                vis = ViewStates.Visible;
            child.Visibility = vis;
        }

            public override void OnViewDragStateChanged(int state)
            {
                var anchoredTop = (int)(_panelLayout._anchorPoint * _panelLayout._slideRange);

                if (_panelLayout._dragHelper.ViewDragState == ViewDragHelper.StateIdle)
                {
                    if (FloatNearlyEqual(_panelLayout._slideOffset, 0))
                    {
                        if (_panelLayout._slideState != SlideState.Expanded)
                        {
                            _panelLayout.UpdateObscuredViewVisibility();
                            _panelLayout.OnPanelExpanded(_panelLayout._slideableView);
                            _panelLayout._slideState = SlideState.Expanded;
                        }
                    }
                    else if (FloatNearlyEqual(_panelLayout._slideOffset, (float)anchoredTop / _panelLayout._slideRange))
                    {
                        if (_panelLayout._slideState != SlideState.Anchored)
                        {
                            _panelLayout.UpdateObscuredViewVisibility();
                            _panelLayout.OnPanelAnchored(_panelLayout._slideableView);
                            _panelLayout._slideState = SlideState.Anchored;
                        }
                    }
                    else if (_panelLayout._slideState != SlideState.Collapsed)
                    {
                        _panelLayout.OnPanelCollapsed(_panelLayout._slideableView);
                        _panelLayout._slideState = SlideState.Collapsed;
                    }
                }
            }