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DefaultNodeCursor.java

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/* -*- indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Marco Kuhlmann <kuhlmann@ps.uni-sb.de>
 *     Guido Tack <tack@gecode.org>
 *
 *  Contributing authors:
 *     Mikael Lagerkvist <lagerkvist@gecode.org>
 *
 *  Copyright:
 *     Marco Kuhlmann, 2005
 *     Guido Tack, 2006
 *
 *  Last modified:
 *     $Date: 2006-10-26 11:31:58 +0200 (Thu, 26 Oct 2006) $ by $Author: tack $
 *     $Revision: 3796 $
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  See the file "LICENSE" for information on usage and
 *  redistribution of this file, and for a
 *     DISCLAIMER OF ALL WARRANTIES.
 *
 */

package org.gecode.gist;

abstract public class DefaultNodeCursor implements NodeCursorInterface {
    
    private Node startNode;
    private Node node;
    
    public DefaultNodeCursor(Node theNode) {
        this.startNode = theNode;
        this.node = theNode;
    }
    
    public Node getCurrentNode() {
        return node;
    }
    
    public boolean mayMoveUpwards() {
        return (node != startNode && ! node.isRoot());
    }
    
    public void moveUpwards() {
        node = node.getParent();
    }
    
    public boolean mayMoveDownwards() {
        return (node.getNumberOfChildren() > 0);
    }
    
    public void moveDownwards() {
        node = node.getFirstChild();
    }
    
    public boolean mayMoveSidewards() {
        return (! node.isLastChild());
    }
    
    public void moveSidewards() {
        node = node.getNextSibling();
    }
    
    abstract public void processCurrentNode(); 
    
}