1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.collections4.iterators;
18
19 import java.util.ListIterator;
20 import java.util.Objects;
21
22 /**
23 * Provides basic behavior for decorating a list iterator with extra functionality.
24 * <p>
25 * All methods are forwarded to the decorated list iterator.
26 * </p>
27 *
28 * @param <E> the type of elements in this iterator.
29 * @since 3.0
30 */
31 public class AbstractListIteratorDecorator<E> implements ListIterator<E> {
32
33 /** The iterator being decorated */
34 private final ListIterator<E> iterator;
35
36 /**
37 * Constructor that decorates the specified iterator.
38 *
39 * @param iterator the iterator to decorate, must not be null
40 * @throws NullPointerException if the iterator is null
41 */
42 public AbstractListIteratorDecorator(final ListIterator<E> iterator) {
43 this.iterator = Objects.requireNonNull(iterator, "iterator");
44 }
45
46 /** {@inheritDoc} */
47 @Override
48 public void add(final E obj) {
49 iterator.add(obj);
50 }
51
52 /**
53 * Gets the iterator being decorated.
54 *
55 * @return the decorated iterator
56 */
57 protected ListIterator<E> getListIterator() {
58 return iterator;
59 }
60
61 /** {@inheritDoc} */
62 @Override
63 public boolean hasNext() {
64 return iterator.hasNext();
65 }
66
67 /** {@inheritDoc} */
68 @Override
69 public boolean hasPrevious() {
70 return iterator.hasPrevious();
71 }
72
73 /** {@inheritDoc} */
74 @Override
75 public E next() {
76 return iterator.next();
77 }
78
79 /** {@inheritDoc} */
80 @Override
81 public int nextIndex() {
82 return iterator.nextIndex();
83 }
84
85 /** {@inheritDoc} */
86 @Override
87 public E previous() {
88 return iterator.previous();
89 }
90
91 /** {@inheritDoc} */
92 @Override
93 public int previousIndex() {
94 return iterator.previousIndex();
95 }
96
97 /** {@inheritDoc} */
98 @Override
99 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 }