Home | History | Annotate | Download | only in collect 
      1 /*
      2  * Copyright (C) 2007 Google Inc.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.common.collect;
     18 
     19 import com.google.common.annotations.GwtCompatible;
     20 import com.google.common.annotations.GwtIncompatible;
     21 
     22 import java.util.Collection;
     23 import java.util.List;
     24 import java.util.ListIterator;
     25 
     26 import javax.annotation.Nullable;
     27 
     28 /**
     29  * A list which forwards all its method calls to another list. Subclasses should
     30  * override one or more methods to modify the behavior of the backing list as
     31  * desired per the <a
     32  * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
     33  *
     34  * <p>This class does not implement {@link java.util.RandomAccess}. If the
     35  * delegate supports random access, the {@code ForwadingList} subclass should
     36  * implement the {@code RandomAccess} interface.
     37  *
     38  * @author Mike Bostock
     39  * @since 2010.01.04 <b>stable</b> (imported from Google Collections Library)
     40  */
     41 @GwtCompatible
     42 public abstract class ForwardingList<E> extends ForwardingCollection<E>
     43     implements List<E> {
     44 
     45   @Override protected abstract List<E> delegate();
     46 
     47   public void add(int index, E element) {
     48     delegate().add(index, element);
     49   }
     50 
     51   public boolean addAll(int index, Collection<? extends E> elements) {
     52     return delegate().addAll(index, elements);
     53   }
     54 
     55   public E get(int index) {
     56     return delegate().get(index);
     57   }
     58 
     59   public int indexOf(Object element) {
     60     return delegate().indexOf(element);
     61   }
     62 
     63   public int lastIndexOf(Object element) {
     64     return delegate().lastIndexOf(element);
     65   }
     66 
     67   public ListIterator<E> listIterator() {
     68     return delegate().listIterator();
     69   }
     70 
     71   public ListIterator<E> listIterator(int index) {
     72     return delegate().listIterator(index);
     73   }
     74 
     75   public E remove(int index) {
     76     return delegate().remove(index);
     77   }
     78 
     79   public E set(int index, E element) {
     80     return delegate().set(index, element);
     81   }
     82 
     83   @GwtIncompatible("List.subList")
     84   public List<E> subList(int fromIndex, int toIndex) {
     85     return Platform.subList(delegate(), fromIndex, toIndex);
     86   }
     87 
     88   @Override public boolean equals(@Nullable Object object) {
     89     return object == this || delegate().equals(object);
     90   }
     91 
     92   @Override public int hashCode() {
     93     return delegate().hashCode();
     94   }
     95 }
     96