/*

     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 25.03.2005

  *

  */

 package net.sourceforge.combean.graph.decorators;

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

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

 import net.sourceforge.combean.util.except.UnsupportedMethodException;

 /**

  * A decorator which returns a specific all nodes iterator, i.e., which

  * enforces traversal of the nodes of the graph in a given order.

  * 

  * @author schickin

  *

  */

 public class OrderedNodesGraph extends AbstractDecoratedGraph

 implements GlobalNodesGraphProp {

     private GlobalNodesGraphProp g = null;

     private NodeIterator itAllNodes = null;

     /**

      * Constructor

      * 

      * @param g the graph the nodes of which shall be traversed in a specific order

      * @param itAllNodes the iterator (with the current implementation

      * getAllNodesIterator() may only be invoked once on the decorated graph) 

      */

     public OrderedNodesGraph(GlobalNodesGraphProp g, NodeIterator itAllNodes) {

         super(g);

         this.g = g;

         this.itAllNodes = itAllNodes;

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.GlobalNodesGraphProp#getNumNodes()

      */

     public int getNumNodes() {

          return this.g.getNumNodes();

     }

     /* (non-Javadoc)

      * @see net.sourceforge.combean.interfaces.graph.GlobalNodesGraphProp#getAllNodesIterator()

      */

     public NodeIterator getAllNodesIterator() {

         NodeIterator result = this.itAllNodes;

         if (result == null) {

             throw new UnsupportedMethodException("OrderedNodes can only produce one iterator for all nodes");

         }

         this.itAllNodes = null;

         return result;

     }

     /**

      * All nested properties except those which refer to the global nodes

      * and their identity (GlobalNodesGraphProp and derivatives) may be nested.

      * 

      * @see net.sourceforge.combean.interfaces.graph.prop.NestedGraphProp#mayNestGraphProp(java.lang.Class)

      */

     public boolean mayNestGraphProp(Class wantedProp) {

          return !GlobalNodesGraphProp.class.isAssignableFrom(wantedProp);

     }

 }