/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.graph.path;
import java.util.Iterator;
import org.geotools.graph.structure.Node;
/**
* Represents a sequence of nodes in a graph.
*
* @author Justin Deoliveira, Refractions Research Inc, jdeolive@refractions.net
*
*
* @source $URL$
*/
public interface NodeSequence {
/**
* Returns the first node in the sequence.
*
* @return Object of tupe Node.
*/
public Node getFirst();
/**
* Returns the last node in the sequence.
*
* @return Object of type node.
*/
public Node getLast();
/**
* Returns the number of nodes in the sequence.
*
* @return an integer representing the number of nodes in the sequence.
*/
public int size();
/**
* Returns an iterator over the nodes.
*
* @return An iterator.
*/
public Iterator iterator();
/**
* Determines if the node sequence id valid based on the rules of the
* implementation.
*
* @return True if valid, otherwise false.
*/
public boolean isValid();
}