/*

     This file is part of Combean.

     Combean is free software; you can redistribute it and/or modify

     it under the terms of the GNU General Public License as published by

     the Free Software Foundation; either version 2 of the License, or

     (at your option) any later version.

     Combean 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 General Public License for more details.

     You should have received a copy of the GNU General Public License

     along with Combean; if not, write to the Free Software

     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

 /*

  * Created on 20.08.2005

  *

  */

 package net.sourceforge.combean.graph.alg.traversal;

 import net.sourceforge.combean.graph.containers.NodeMapAdvisor;

 import net.sourceforge.combean.interfaces.graph.Edge;

 import net.sourceforge.combean.interfaces.graph.Graph;

 import net.sourceforge.combean.interfaces.graph.Node;

 import net.sourceforge.combean.interfaces.graph.alg.traverse.TraversalVisitor;

 import net.sourceforge.combean.interfaces.graph.containers.NodeMap;

 import net.sourceforge.combean.interfaces.graph.prop.NeighborhoodGraphProp;

 /**

  * @author schickin

  *

  */

 public class ConstructPredMapVisitor extends IdleTraversalVisitor implements

         TraversalVisitor {

     private NodeMap<Edge> predMap = null;

     private NeighborhoodGraphProp neigh = null;

     private Node target = null;

     private boolean targetReached = false;

     /**

      * constructor 

      */

     public ConstructPredMapVisitor() {

         super();

     }

     /**

      * @return Returns the predMap.

      */

     public final NodeMap<Edge> getPredMap() {

         return this.predMap;

     }

     /**

      * @param predMap The predMap to set.

      */

     public final void setPredMap(NodeMap<Edge> predMap) {

         this.predMap = predMap;

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.alg.traverse.TraversalVisitor#init(net.sourceforge.combean.interfaces.graph.Graph)

      */

     public void init(Graph g) {

         this.neigh = (NeighborhoodGraphProp) g;

         if (this.predMap == null) {

             this.predMap = NodeMapAdvisor.getFastestNodeMap(g);

         }

         this.predMap.init(g);

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.alg.traverse.TraversalVisitor#initLocal(net.sourceforge.combean.interfaces.graph.Graph, net.sourceforge.combean.interfaces.graph.Node)

      */

     public void initLocal(Graph g, Node startNode) {

         init(g);

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.alg.traverse.TraversalVisitor#openNeighbor(net.sourceforge.combean.interfaces.graph.Edge, net.sourceforge.combean.interfaces.graph.Node)

      */

     public void openNeighbor(Edge e, Node from) {

         Node to = this.neigh.getOtherNode(e, from); 

         this.predMap.put(to, e);

         if (to.equals(this.target)) {

             this.targetReached = true;

         }

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.alg.traverse.TraversalVisitor#readyToTerminate()

      */

     public boolean readyToTerminate() {

         return this.targetReached;

     }

     /**

      * Set target node where the construction of the predecessor map

      * shall terminate. If no target node is set, all reachable nodes

      * will be visited.

      * 

      * @param target The target to set.

      */

     public final void setTarget(Node target) {

         this.target = target;

     }

 }