gecko/gfx/layers/DirectedGraph.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Matt Woodrow <mwoodrow@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#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:
PRBool 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;
};
}
}
#endif // GFX_DIRECTEDGRAPH_H