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JGraphT is a free Java graph library
that provides mathematical graph-theory objects and algorithms
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/* ==========================================
* JGraphT : a free Java graph-theory library
* ==========================================
*
* Project Info: http://jgrapht.sourceforge.net/
* Project Creator: Barak Naveh (http://sourceforge.net/users/barak_naveh)
*
* (C) Copyright 2003-2007, by Barak Naveh and Contributors.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
/* ------------------
* IntegerNameProvider.java
* ------------------
* (C) Copyright 2005-2007, by Charles Fry and Contributors.
*
* Original Author: Charles Fry
*
* $Id: IntegerNameProvider.java 568 2007-09-30 00:12:18Z perfecthash $
*
* Changes
* -------
* 13-Dec-2005 : Initial Version (CF);
*
*/
package org.jgrapht.ext;
import java.util.*;
import org.jgrapht.event.*;
/**
* Assigns a unique integer to represent each vertex. Each instance of
* IntegerNameProvider maintains an internal map between every vertex it has
* ever seen and the unique integer representing that vertex. As a result it is
* probably desirable to have a separate instance for each distinct graph.
*
* @author Charles Fry
*/
public class IntegerNameProvider
implements VertexNameProvider
{
//~ Instance fields --------------------------------------------------------
private int nextID = 1;
private final Map idMap = new HashMap();
//~ Methods ----------------------------------------------------------------
/**
* Clears all cached identifiers, and resets the unique identifier counter.
*/
public void clear()
{
nextID = 1;
idMap.clear();
}
/**
* Returns the String representation of the unique integer representing a
* vertex.
*
* @param vertex the vertex to be named
*
* @return the name of
*
* @see GraphListener#edgeAdded(GraphEdgeChangeEvent)
*/
public String getVertexName(V vertex)
{
Integer id = idMap.get(vertex);
if (id == null) {
id = nextID++;
idMap.put(vertex, id);
}
return id.toString();
}
}
// End IntegerNameProvider.java