/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef GFX_DIRECTEDGRAPH_H #define GFX_DIRECTEDGRAPH_H #include "gfxTypes.h" #include "nsTArray.h" namespace mozilla { namespace layers { template <typename T> class DirectedGraph { public: class Edge { public: Edge(T aFrom, T aTo) : mFrom(aFrom), mTo(aTo) {} bool operator==(const Edge& aOther) const { return mFrom == aOther.mFrom && mTo == aOther.mTo; } T mFrom; T mTo; }; class RemoveEdgesToComparator { public: bool Equals(const Edge& a, T const& b) const { return a.mTo == b; } }; /** * Add a new edge to the graph. */ void AddEdge(Edge aEdge) { NS_ASSERTION(!mEdges.Contains(aEdge), "Adding a duplicate edge!"); mEdges.AppendElement(aEdge); } void AddEdge(T aFrom, T aTo) { AddEdge(Edge(aFrom, aTo)); } /** * Get the list of edges. */ const nsTArray<Edge>& GetEdgeList() const { return mEdges; } /** * Remove the given edge from the graph. */ void RemoveEdge(Edge aEdge) { mEdges.RemoveElement(aEdge); } /** * Remove all edges going into aNode. */ void RemoveEdgesTo(T aNode) { RemoveEdgesToComparator c; while (mEdges.RemoveElement(aNode, c)) {} } /** * Get the number of edges going into aNode. */ unsigned int NumEdgesTo(T aNode) { unsigned int count = 0; for (unsigned int i = 0; i < mEdges.Length(); i++) { if (mEdges.ElementAt(i).mTo == aNode) { count++; } } return count; } /** * Get the list of all edges going from aNode */ void GetEdgesFrom(T aNode, nsTArray<Edge>& aResult) { for (unsigned int i = 0; i < mEdges.Length(); i++) { if (mEdges.ElementAt(i).mFrom == aNode) { aResult.AppendElement(mEdges.ElementAt(i)); } } } /** * Get the total number of edges. */ unsigned int GetEdgeCount() { return mEdges.Length(); } private: nsTArray<Edge> mEdges; }; } // namespace layers } // namespace mozilla #endif // GFX_DIRECTEDGRAPH_H