gecko-dev/gfx/layers/DirectedGraph.h

102 строки
2.3 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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