/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.collections15.keyvalue;

import java.util.Map;

import org.apache.commons.collections15.KeyValue;

/**
 * Provides a base decorator that allows additional functionality to be added to
 * a {@link java.util.Map.Entry Map.Entry}.
 *
 * @since Commons Collections 3.0
 * @version $Revision$ $Date$
 *
 * @author Stephen Colebourne
 */
public abstract class AbstractMapEntryDecorator<K, V>
		implements Map.Entry<K, V>, KeyValue<K, V> {

	/** The <code>Map.Entry</code> to decorate */
	protected final Map.Entry<K, V> entry;

	/**
	 * Constructor that wraps (not copies).
	 *
	 * @param entry
	 *            the <code>Map.Entry</code> to decorate, must not be null
	 * @throws IllegalArgumentException
	 *             if the collection is null
	 */
	public AbstractMapEntryDecorator(Map.Entry<K, V> entry) {
		if (entry == null) {
			throw new IllegalArgumentException("Map Entry must not be null");
		}
		this.entry = entry;
	}

	/**
	 * Gets the map being decorated.
	 * 
	 * @return the decorated map
	 */
	protected Map.Entry<K, V> getMapEntry() {
		return entry;
	}

	// -----------------------------------------------------------------------
	@Override
	public K getKey() {
		return entry.getKey();
	}

	@Override
	public V getValue() {
		return entry.getValue();
	}

	@Override
	public V setValue(V object) {
		return entry.setValue(object);
	}

	@Override
	public boolean equals(Object object) {
		if (object == this) {
			return true;
		}
		return entry.equals(object);
	}

	@Override
	public int hashCode() {
		return entry.hashCode();
	}

	@Override
	public String toString() {
		return entry.toString();
	}

}