// optimize the creation of the ForceDirectedNetwork:
// only create it when there are Nodes or Links added or removed
protected override void PerformLayout()
{
Diagram diagram = this.Diagram;
if (diagram == null)
{
return;
}
var cfdlayout = diagram.Layout as ContinuousForceDirectedLayout;
if (cfdlayout != null)
{
// assume there are no Groups with their own Layout
if (!cfdlayout.ValidLayout)
{
// make sure there's no animation interfering with ContinuousForceDirectedLayout
this.Animated = false;
// don't set Wait cursor during drag
diagram.Cursor = null;
// the ForceDirectedNetwork needs to be cleared whenever a Node or Link is added or removed
var net = cfdlayout.Network;
if (net == null) // create a new one
{
net = new ForceDirectedNetwork();
net.AddNodesAndLinks(diagram.Nodes.Where(n => CanLayoutPart(n, cfdlayout)),
diagram.Links.Where(l => CanLayoutPart(l, cfdlayout)));
cfdlayout.Network = net;
}
else // update all vertex.Bounds
{
foreach (ForceDirectedVertex v in net.Vertexes)
{
Node n = v.Node;
if (n != null)
{
v.Bounds = n.Bounds;
}
}
}
// don't need to re-collect the appropriate Nodes and Links to pass to DoLayout
this.IsLayingOut = true;
cfdlayout.DoLayout(null, null);
this.IsLayingOut = false;
cfdlayout.ValidLayout = true;
// DoLayout normally discards the Network; keep it for next time
cfdlayout.Network = net;
}
}
else
{
base.PerformLayout();
}
}
public override ForceDirectedNetwork MakeNetwork(IEnumerable <Node> nodes, IEnumerable <Link> links)
{
ForceDirectedNetwork net = base.MakeNetwork(nodes, links);
foreach (ForceDirectedVertex v in net.Vertexes)
{
Node node = v.Node;
if (node != null)
{
v.IsFixed = node.IsSelected;
}
}
return(net);
}
