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 21 import java.util.Collection; 22 import java.util.Iterator; 23 24 /** 25 * A collection which forwards all its method calls to another collection. 26 * Subclasses should override one or more methods to modify the behavior of 27 * the backing collection as desired per the <a 28 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. 29 * 30 * @see ForwardingObject 31 * @author Kevin Bourrillion 32 * @since 2010.01.04 <b>stable</b> (imported from Google Collections Library) 33 */ 34 @GwtCompatible 35 public abstract class ForwardingCollection<E> extends ForwardingObject 36 implements Collection<E> { 37 delegate()38 @Override protected abstract Collection<E> delegate(); 39 iterator()40 public Iterator<E> iterator() { 41 return delegate().iterator(); 42 } 43 size()44 public int size() { 45 return delegate().size(); 46 } 47 removeAll(Collection<?> collection)48 public boolean removeAll(Collection<?> collection) { 49 return delegate().removeAll(collection); 50 } 51 isEmpty()52 public boolean isEmpty() { 53 return delegate().isEmpty(); 54 } 55 contains(Object object)56 public boolean contains(Object object) { 57 return delegate().contains(object); 58 } 59 toArray()60 public Object[] toArray() { 61 return delegate().toArray(); 62 } 63 toArray(T[] array)64 public <T> T[] toArray(T[] array) { 65 return delegate().toArray(array); 66 } 67 add(E element)68 public boolean add(E element) { 69 return delegate().add(element); 70 } 71 remove(Object object)72 public boolean remove(Object object) { 73 return delegate().remove(object); 74 } 75 containsAll(Collection<?> collection)76 public boolean containsAll(Collection<?> collection) { 77 return delegate().containsAll(collection); 78 } 79 addAll(Collection<? extends E> collection)80 public boolean addAll(Collection<? extends E> collection) { 81 return delegate().addAll(collection); 82 } 83 retainAll(Collection<?> collection)84 public boolean retainAll(Collection<?> collection) { 85 return delegate().retainAll(collection); 86 } 87 clear()88 public void clear() { 89 delegate().clear(); 90 } 91 } 92