internal CardinalDirection GetDirection()
        {
            var rectangle = new Rectangle(ParentElement.Location, ParentElement.Size);
            var point     = new Point(location.X - ParentElement.Location.X + size.Width / 2,
                                      location.Y - ParentElement.Location.Y + size.Height / 2);

            return(DiagramHelper.GetDirection(rectangle, point));
        }