/// <summary>
/// Pops a graph handle from stack, no checks performed.
/// </summary>
private void EndGraphInternal()
{
GraphHandle h = _subGraphs.Pop();
h.MarkAsUsed();
Line("}");
}
public IGraphHandle StartGraph(GraphMode graphMode, bool strict)
{
_graphMode = graphMode;
if (_subGraphs.Count != 0)
{
throw new InvalidOperationException();
}
string line = "";
if (strict)
{
line += "strict ";
}
line += graphMode == GraphMode.Graph ? "graph" : "digraph";
line += " \"\" {";
Line(line);
GraphHandle g = new GraphHandle(this);
_subGraphs.Push(g);
return(g);
}
/// <summary>
/// Ends graph or subgraph when called by handle disposal.
/// </summary>
internal void EndGraphFromHandle(GraphHandle handle)
{
if (!ReferenceEquals(_subGraphs.Peek(), handle))
{
throw new InvalidOperationException();
}
EndGraphInternal();
}
public IGraphHandle StartSubGraph()
{
if (_subGraphs.Count == 0)
{
throw new InvalidOperationException();
}
Line("subgraph {");
GraphHandle g = new GraphHandle(this);
_subGraphs.Push(g);
return(g);
}