/*
Copyright 2008-2010 Gephi
Authors : Mathieu Bastian <mathieu.bastian@gephi.org>
Website : http://www.gephi.org
This file is part of Gephi.
DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
Copyright 2011 Gephi Consortium. All rights reserved.
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"License"). You may not use this file except in compliance with the
License. You can obtain a copy of the License at
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or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
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License. When distributing the software, include this License Header
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Contributor(s):
Portions Copyrighted 2011 Gephi Consortium.
*/
package org.gephi.graph.api;
/**
* Graph with only undirected edges. Note that undirected graph can be obtained
* even if all edges are directed. The graph is just taking care to ignore opposite
* edges.
*
* @author Mathieu Bastian
* @see GraphModel
*/
public interface UndirectedGraph extends Graph {
/**
* Add an undirected edge between<code>node1</code> and <code>node2</code>to the graph.
* Graph does not accept parallel edges.
* Fails if a such edge already exists in the graph.
* @param node1 the first node
* @param node2 the second node
* @return true if add is successful, false otherwise
* @throws IllegalArgumentException if <code>source</code> or <code>target</code>
* is <code>null</code> or not legal nodes for this <code>edge</code>
* @throws IllegalMonitorStateException if the current thread is holding a read lock
*/
public boolean addEdge(Node node1, Node node2);
/**
* Find and returns an edge that connects <code>node1</code> and <code>node2</code>. Returns
* <code>null</code> if no such edge is found.
* <p><b>Warning:</b> This method is not thread safe, be sure to call it in a locked
* statement.
* @param node1 the first incident node of the queried edge
* @param node2 thge second incident node of the queried edge
* @return an edge that connects <code>node1</code> and <code>node2</code>
* or <code>null</code> if no such edge exists
* @throws IllegalArgumentException if <code>node1</code> or <code>node2</code>
* is <code>null</code> or not legal nodes in the graph
*/
public Edge getEdge(Node node1, Node node2);
}