private void OnAddEdge(object sender, IEdge edge)
{
edge.SetAlgorithmObj(_KH_PANE_GRAPH_PRIOR, 0);
edge.SetAlgorithmObj(_KH_PANE_BOUNDS, new RectangleF());
edge.SetAlgorithmObj(Flags.State.None.ToString(), false);
edge.SetAlgorithmObj(Flags.State.Focus.ToString(), false);
edge.SetAlgorithmObj(Flags.State.Hover.ToString(), false);
edge.SetAlgorithmObj(Flags.State.DraggedOver.ToString(), false);
edge.SetAlgorithmObj(Flags.State.Dragging.ToString(), false);
edge.SetAlgorithmObj(Flags.State.HighLight.ToString(), false);
edge.OnAttributeChange += OnAttributeChange;
NeedRefresh = true;
//this.Refresh();
}