/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/map/AbstractOrderedMapDecorator.java,v 1.1 2003/11/20 22:33:54 scolebourne Exp $
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.commons.collections.map;

import org.apache.commons.collections.iterators.MapIterator;
import org.apache.commons.collections.iterators.OrderedMapIterator;

/** 
 * Provides a base decorator that enables additional functionality to be added
 * to an OrderedMap via decoration.
 * <p>
 * Methods are forwarded directly to the decorated map.
 * <p>
 * This implementation does not perform any special processing with the map views.
 * Instead it simply returns the set/collection from the wrapped map. This may be
 * undesirable, for example if you are trying to write a validating implementation
 * it would provide a loophole around the validation.
 * But, you might want that loophole, so this class is kept simple.
 *
 * @since Commons Collections 3.0
 * @version $Revision: 1.1 $ $Date: 2003/11/20 22:33:54 $
 * 
 * @author Stephen Colebourne
 */
public abstract class AbstractOrderedMapDecorator extends AbstractMapDecorator implements OrderedMap {
    
    /**
     * Constructor that wraps (not copies).
     *
     * @param map  the map to decorate, must not be null
     * @throws IllegalArgumentException if the collection is null
     */
    public AbstractOrderedMapDecorator(OrderedMap map) {
        super(map);
    }

    /**
     * Gets the map being decorated.
     * 
     * @return the decorated map
     */
    protected OrderedMap getOrderedMap() {
        return (OrderedMap) map;
    }

    //-----------------------------------------------------------------------
    public Object firstKey() {
        return getOrderedMap().firstKey();
    }

    public Object lastKey() {
        return getOrderedMap().lastKey();
    }

    public Object nextKey(Object key) {
        return getOrderedMap().nextKey(key);
    }

    public Object previousKey(Object key) {
        return getOrderedMap().previousKey(key);
    }

    public MapIterator mapIterator() {
        return getOrderedMap().mapIterator();
    }

    public OrderedMapIterator orderedMapIterator() {
        return getOrderedMap().orderedMapIterator();
    }

}

Add new decorator abstract class for OrderedMap