Artemis.Styles.DropTargetAdorners.DropTargetMetroHighlightAdorner.OnRender C# (CSharp) Method

        protected override void OnRender(DrawingContext drawingContext)
        {
            var visualTargetItem = DropInfo.VisualTargetItem;
            if (visualTargetItem != null)
            {
                var rect = Rect.Empty;

                var tvItem = visualTargetItem as TreeViewItem;
                if (tvItem != null && VisualTreeHelper.GetChildrenCount(tvItem) > 0)
                {
                    var descendant = VisualTreeHelper.GetDescendantBounds(tvItem);
                    var translatePoint = tvItem.TranslatePoint(new Point(), AdornedElement);
                    var itemRect = new Rect(translatePoint, tvItem.RenderSize);
                    descendant.Union(itemRect);
                    rect = new Rect(translatePoint, new Size(descendant.Width - translatePoint.X, tvItem.ActualHeight));
                }
                if (rect.IsEmpty)
                {
                    rect = new Rect(visualTargetItem.TranslatePoint(new Point(), AdornedElement),
                        VisualTreeHelper.GetDescendantBounds(visualTargetItem).Size);
                }
                var color = (Color) ThemeManager.DetectAppStyle(Application.Current).Item2.Resources["AccentColor"];
                drawingContext.DrawRoundedRectangle(null, new Pen(new SolidColorBrush(color), 2), rect, 2, 2);
            }
        }
    }