001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.commons.collections.map;
018    
019    import org.apache.commons.collections.MapIterator;
020    import org.apache.commons.collections.OrderedMap;
021    import org.apache.commons.collections.OrderedMapIterator;
022    
023    /** 
024     * Provides a base decorator that enables additional functionality to be added
025     * to an OrderedMap via decoration.
026     * <p>
027     * Methods are forwarded directly to the decorated map.
028     * <p>
029     * This implementation does not perform any special processing with the map views.
030     * Instead it simply returns the set/collection from the wrapped map. This may be
031     * undesirable, for example if you are trying to write a validating implementation
032     * it would provide a loophole around the validation.
033     * But, you might want that loophole, so this class is kept simple.
034     *
035     * @since Commons Collections 3.0
036     * @version $Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $
037     * 
038     * @author Stephen Colebourne
039     */
040    public abstract class AbstractOrderedMapDecorator
041            extends AbstractMapDecorator implements OrderedMap {
042    
043        /**
044         * Constructor only used in deserialization, do not use otherwise.
045         * @since Commons Collections 3.1
046         */
047        protected AbstractOrderedMapDecorator() {
048            super();
049        }
050    
051        /**
052         * Constructor that wraps (not copies).
053         *
054         * @param map  the map to decorate, must not be null
055         * @throws IllegalArgumentException if the collection is null
056         */
057        public AbstractOrderedMapDecorator(OrderedMap map) {
058            super(map);
059        }
060    
061        /**
062         * Gets the map being decorated.
063         * 
064         * @return the decorated map
065         */
066        protected OrderedMap getOrderedMap() {
067            return (OrderedMap) map;
068        }
069    
070        //-----------------------------------------------------------------------
071        public Object firstKey() {
072            return getOrderedMap().firstKey();
073        }
074    
075        public Object lastKey() {
076            return getOrderedMap().lastKey();
077        }
078    
079        public Object nextKey(Object key) {
080            return getOrderedMap().nextKey(key);
081        }
082    
083        public Object previousKey(Object key) {
084            return getOrderedMap().previousKey(key);
085        }
086    
087        public MapIterator mapIterator() {
088            return getOrderedMap().mapIterator();
089        }
090    
091        public OrderedMapIterator orderedMapIterator() {
092            return getOrderedMap().orderedMapIterator();
093        }
094    
095    }