/// <summary>
/// An edge can define a cluster as logical head.
/// This is used to fake edges to and from clusters by clipping the edge on the borders of the logical head.
/// </summary>
public void SetLogicalHead(SubGraph lhead)
{
if (!lhead.IsCluster())
{
throw new InvalidOperationException("ltail must be a cluster");
}
if (!MyRootGraph.IsCompound())
{
throw new InvalidOperationException("rootgraph must be compound for lheads/ltails to be used");
}
string lheadname = lhead.GetName();
SafeSetAttribute("lhead", lheadname, "");
}
/// <summary>
/// FIXME: use an actual subg equivalent to agsubedge and agsubnode
/// https://github.com/ellson/graphviz/issues/1206
/// This might cause a new subgraph creation.
/// </summary>
public void AddExisting(SubGraph subgraph)
{
Agsubg(_ptr, subgraph.GetName(), 1);
}