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 */
017package org.apache.commons.collections4.list;
018
019import java.util.Collection;
020import java.util.List;
021import java.util.ListIterator;
022
023import org.apache.commons.collections4.collection.AbstractCollectionDecorator;
024
025/**
026 * Decorates another {@link List} to provide additional behaviour.
027 * <p>
028 * Methods are forwarded directly to the decorated list.
029 *
030 * @param <E> the type of the elements in the list
031 * @since 3.0
032 */
033public abstract class AbstractListDecorator<E> extends AbstractCollectionDecorator<E>
034        implements List<E> {
035
036    /** Serialization version--necessary in an abstract class? */
037    private static final long serialVersionUID = 4500739654952315623L;
038
039    /**
040     * Constructor only used in deserialization, do not use otherwise.
041     * @since 3.1
042     */
043    protected AbstractListDecorator() {
044        super();
045    }
046
047    /**
048     * Constructor that wraps (not copies).
049     *
050     * @param list  the list to decorate, must not be null
051     * @throws NullPointerException if list is null
052     */
053    protected AbstractListDecorator(final List<E> list) {
054        super(list);
055    }
056
057    /**
058     * Gets the list being decorated.
059     *
060     * @return the decorated list
061     */
062    @Override
063    protected List<E> decorated() {
064        return (List<E>) super.decorated();
065    }
066
067    @Override
068    public boolean equals(final Object object) {
069        return object == this || decorated().equals(object);
070    }
071
072    @Override
073    public int hashCode() {
074        return decorated().hashCode();
075    }
076
077    //-----------------------------------------------------------------------
078
079    @Override
080    public void add(final int index, final E object) {
081        decorated().add(index, object);
082    }
083
084    @Override
085    public boolean addAll(final int index, final Collection<? extends E> coll) {
086        return decorated().addAll(index, coll);
087    }
088
089    @Override
090    public E get(final int index) {
091        return decorated().get(index);
092    }
093
094    @Override
095    public int indexOf(final Object object) {
096        return decorated().indexOf(object);
097    }
098
099    @Override
100    public int lastIndexOf(final Object object) {
101        return decorated().lastIndexOf(object);
102    }
103
104    @Override
105    public ListIterator<E> listIterator() {
106        return decorated().listIterator();
107    }
108
109    @Override
110    public ListIterator<E> listIterator(final int index) {
111        return decorated().listIterator(index);
112    }
113
114    @Override
115    public E remove(final int index) {
116        return decorated().remove(index);
117    }
118
119    @Override
120    public E set(final int index, final E object) {
121        return decorated().set(index, object);
122    }
123
124    @Override
125    public List<E> subList(final int fromIndex, final int toIndex) {
126        return decorated().subList(fromIndex, toIndex);
127    }
128
129}