    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}