/* $Id: GenCompositeClasses2.java 17846 2010-01-12 19:37:12Z linus $
 *****************************************************************************
 * Copyright (c) 2009 Contributors - see below
 * 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:
 *    linus
 *****************************************************************************
 *
 * Some portions of this file was previously release using the BSD License:
 */

// Copyright (c) 2008 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph appear in all copies. This software program and
// documentation are copyrighted by The Regents of the University of
// California. The software program and documentation are supplied "AS
// IS", without any accompanying services from The Regents. The Regents
// does not warrant that the operation of the program will be
// uninterrupted or error-free. The end-user understands that the program
// was developed for research purposes and is advised not to rely
// exclusively on the program for any reason. IN NO EVENT SHALL THE
// UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT,
// SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING LOST PROFITS,
// ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
// THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE. THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
// PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
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package org.argouml.uml;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.argouml.model.Model;
import org.argouml.util.ChildGenerator;

/**
 * Utility class to generate a list of the "children" of a class which are the
 * other classes that are associated with the parent class, and that Association
 * has a COMPOSITE end at the parent. This is used in one of the critics.
 * 
 * @see org.argouml.uml.cognitive.critics.CrCircularComposition
 * @stereotype singleton
 */
public class GenCompositeClasses2 implements
        ChildGenerator {

    /**
     * This SINGLETON is used in CrCircularComposition.
     *
     */
    private static final GenCompositeClasses2 SINGLETON =
        new GenCompositeClasses2();

    /**
     * @return Return the singleton
     */
    public static GenCompositeClasses2 getInstance() {
        return SINGLETON;
    }
    
    public Iterator childIterator(Object parent) {
        return collectChildren(parent).iterator();
    }

    /**
     * Collect children.<p>
     *
     * @param o the parent element
     * @return a collection of children.
     */
    protected Collection collectChildren(Object o) {
        List res = new ArrayList();
        if (!(Model.getFacade().isAClassifier(o))) {
            return res;
        }
        Object cls = o;
        List ends = new ArrayList(Model.getFacade().getAssociationEnds(cls));
        if (ends == null) {
            return res;
        }
        Iterator assocEnds = ends.iterator();
        while (assocEnds.hasNext()) {
            Object ae = assocEnds.next();
            if (Model.getAggregationKind().getComposite().equals(
                    Model.getFacade().getAggregation(ae))) {
                Object asc = Model.getFacade().getAssociation(ae);
                ArrayList conn =
                    new ArrayList(Model.getFacade().getConnections(asc));
                if (conn == null || conn.size() != 2) {
                    continue;
                }
                Object otherEnd =
                    (ae == conn.get(0)) ? conn.get(1) : conn.get(0);
                if (Model.getFacade().getType(ae)
                        != Model.getFacade().getType(otherEnd)) {
                    res.add(Model.getFacade().getType(otherEnd));
                }
            }
        }
        return res;
    }

}