IGraphDataSource.java

/*******************************************************************************
 * Copyright (c) 2010-2012, Tamas Szabo, Istvan Rath and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Tamas Szabo - initial API and implementation
 *******************************************************************************/

package org.eclipse.incquery.runtime.base.itc.igraph;

import java.io.Serializable;
import java.util.List;
import java.util.Set;

/**
 * This interface is used to provide information about the graph to the observers.
 * 
 * @author Tamas Szabo
 * 
 * @param <V>
 *            the type of the nodes in the graph
 */
public interface IGraphDataSource<V> extends Serializable {

    /**
     * Attach a new graph observer.
     * 
     * Note that the order of attaching the observers may be important (some observers will be notified earlier than
     * others).
     * 
     * @param go
     *            the graph observer
     */
    public void attachObserver(IGraphObserver<V> go);

    /**
     * Detach an existing observer.
     * 
     * @param go
     *            the graph observer
     */
    public void detachObserver(IGraphObserver<V> go);

    /**
     * Get all nodes of the graph.
     * 
     * @return the set of all nodes
     */
    public Set<V> getAllNodes();

    /**
     * Get those nodes that are the target of an edge starting with source. The list is necessary because there can be
     * more edges between two nodes. If no such edge can be found than the method returns null.
     * 
     * @param source
     *            the source node
     * @return the list of target nodes or null if no targets can be found
     */
    public List<V> getTargetNodes(V source);
}