Adorner for Line/linegeometry

K, so I kind of gave up on trying to draw thumbs on the ends of my line but instead I used ellipses (they weren't supposed to do anything anyway, just provide visual cues)

Here's the code I came up with for anyone who cares (adornes a connectorView which is essentially a linegeometry):

public class LineAdorner : Adorner
    {
        public LineAdorner(UIElement adornedElement)
            : base(adornedElement)
        {
        }
        protected override void OnRender(DrawingContext drawingContext)
        {
            if (this.AdornedElement.GetType() == typeof(ConnectorView))
            {
                ConnectorView target = this.AdornedElement as ConnectorView;
                drawingContext.DrawEllipse(Brushes.Black, null, target.StartPoint, 4, 4);
                drawingContext.DrawEllipse(Brushes.Black, null, target.EndPoint, 4, 4);
            }
        }
    }