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.iterators;
018
019import java.util.ListIterator;
020import java.util.Objects;
021
022/**
023 * Provides basic behavior for decorating a list iterator with extra functionality.
024 * <p>
025 * All methods are forwarded to the decorated list iterator.
026 * </p>
027 *
028 * @param <E> the type of elements in this iterator.
029 * @since 3.0
030 */
031public class AbstractListIteratorDecorator<E> implements ListIterator<E> {
032
033    /** The iterator being decorated */
034    private final ListIterator<E> iterator;
035
036    /**
037     * Constructor that decorates the specified iterator.
038     *
039     * @param iterator  the iterator to decorate, must not be null
040     * @throws NullPointerException if the iterator is null
041     */
042    public AbstractListIteratorDecorator(final ListIterator<E> iterator) {
043        this.iterator = Objects.requireNonNull(iterator, "iterator");
044    }
045
046    /** {@inheritDoc} */
047    @Override
048    public void add(final E obj) {
049        iterator.add(obj);
050    }
051
052    /**
053     * Gets the iterator being decorated.
054     *
055     * @return the decorated iterator
056     */
057    protected ListIterator<E> getListIterator() {
058        return iterator;
059    }
060
061    /** {@inheritDoc} */
062    @Override
063    public boolean hasNext() {
064        return iterator.hasNext();
065    }
066
067    /** {@inheritDoc} */
068    @Override
069    public boolean hasPrevious() {
070        return iterator.hasPrevious();
071    }
072
073    /** {@inheritDoc} */
074    @Override
075    public E next() {
076        return iterator.next();
077    }
078
079    /** {@inheritDoc} */
080    @Override
081    public int nextIndex() {
082        return iterator.nextIndex();
083    }
084
085    /** {@inheritDoc} */
086    @Override
087    public E previous() {
088        return iterator.previous();
089    }
090
091    /** {@inheritDoc} */
092    @Override
093    public int previousIndex() {
094        return iterator.previousIndex();
095    }
096
097    /** {@inheritDoc} */
098    @Override
099    public void remove() {
100        iterator.remove();
101    }
102
103    /** {@inheritDoc} */
104    @Override
105    public void set(final E obj) {
106        iterator.set(obj);
107    }
108
109}