/// <summary>
/// Add a plain subgraph with given name to self, containing the nodes that occur both in origin
/// and the filter. In other words, filter the origin subgraph by the filter subgraph on node-level.
/// Attributes are copied from origin to the result.
///
/// Side effect: adds the returned subgraph to self.
/// </summary>
public SubGraph AddSubgraphFilteredByNodes(string name, SubGraph origin, IEnumerable <Node> filter)
{
SubGraph result = GetOrAddSubgraph(name);
foreach (var node in origin.Nodes().Where(filter.Contains))
{
result.AddExisting(node);
}
origin.CopyAttributesTo(result);
return(result);
}
/// <summary>
/// Create a subgraph consisting of nodes from the given nodes.
/// Edges are added to the result if both endpoints are among the nodes.
/// Subgraphs are added to the result if they have nodes in the given nodelist.
/// The names of the Subgraphs are of the form "name:subgraphname".
///
/// Side effect: adds the returned subgraph (and its children) to self.
/// </summary>
public SubGraph AddSubgraphFromNodes(string name, IEnumerable <Node> nodes)
{
// Freeze the list of descendants,
// since we are going to add subgraphs while iterating over existing subgraphs
List <SubGraph> descendants = Descendants().ToList();
SubGraph result = GetOrAddSubgraph(name);
foreach (var node in nodes)
{
result.AddExisting(node);
}
Debug.Assert(result.Nodes().Count() == nodes.Count());
// All that remains to do is to patch up the result by adding edges and subgraphs
foreach (var node in result.Nodes())
{
foreach (var edge in node.EdgesOut(this))
{
if (result.Contains(edge.Head()))
{
result.AddExisting(edge);
}
}
}
Debug.Assert(result.Nodes().Count() == nodes.Count());
// Iterate over the (frozen) existing subgraphs and add new filtered subgraphs
// in the same hierarchical position as their unfiltered counterparts.
foreach (var subgraph in descendants)
{
string filteredsubgraphname = name + ":" + subgraph.GetName();
Debug.WriteLine("Adding filtered subgraph {0}", filteredsubgraphname);
Graph parent = subgraph.Parent();
Graph filteredparent;
if (parent.Equals(this))
{
filteredparent = result;
}
else
{
string parentname = name + ":" + parent.GetName();
filteredparent = result.GetDescendantByName(parentname);
Debug.Assert(filteredparent != null);
}
filteredparent.AddSubgraphFilteredByNodes(filteredsubgraphname, subgraph, nodes);
}
Debug.Assert(result.Nodes().Count() == nodes.Count());
// Remove subgraphs again if they are empty
// Again, we have to freeze the descendants we are enumerating, since we are disposing on the fly
result.SafeDeleteSubgraphs(s => !s.Nodes().Any());
Debug.Assert(result.Nodes().Count() == nodes.Count());
return(result);
}
