001 /* 002 * Copyright (C) 2007 Google Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017 package com.google.common.collect; 018 019 import com.google.common.annotations.GwtCompatible; 020 021 import java.util.ListIterator; 022 023 /** 024 * A list iterator which forwards all its method calls to another list 025 * iterator. Subclasses should override one or more methods to modify the 026 * behavior of the backing iterator as desired per the <a 027 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 028 * 029 * @author Mike Bostock 030 * @since 2 (imported from Google Collections Library) 031 */ 032 @GwtCompatible 033 public abstract class ForwardingListIterator<E> extends ForwardingIterator<E> 034 implements ListIterator<E> { 035 036 /** Constructor for use by subclasses. */ 037 protected ForwardingListIterator() {} 038 039 @Override protected abstract ListIterator<E> delegate(); 040 041 public void add(E element) { 042 delegate().add(element); 043 } 044 045 public boolean hasPrevious() { 046 return delegate().hasPrevious(); 047 } 048 049 public int nextIndex() { 050 return delegate().nextIndex(); 051 } 052 053 public E previous() { 054 return delegate().previous(); 055 } 056 057 public int previousIndex() { 058 return delegate().previousIndex(); 059 } 060 061 public void set(E element) { 062 delegate().set(element); 063 } 064 }