1/* 2 * Copyright (C) 2009 The Guava Authors 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 17package com.google.common.collect; 18 19import java.util.Collection; 20import java.util.Collections; 21import java.util.Set; 22 23import javax.annotation.Nullable; 24 25/** 26 * GWT implementation of {@link ImmutableSet} that forwards to another {@code Set} implementation. 27 * 28 * @author Hayward Chan 29 */ 30@SuppressWarnings("serial") // Serialization only done in GWT. 31public abstract class ForwardingImmutableSet<E> extends ImmutableSet<E> { 32 private final transient Set<E> delegate; 33 34 ForwardingImmutableSet(Set<E> delegate) { 35 // TODO(cpovirk): are we over-wrapping? 36 this.delegate = Collections.unmodifiableSet(delegate); 37 } 38 39 @Override public UnmodifiableIterator<E> iterator() { 40 return Iterators.unmodifiableIterator(delegate.iterator()); 41 } 42 43 @Override public boolean contains(@Nullable Object object) { 44 return object != null && delegate.contains(object); 45 } 46 47 @Override public boolean containsAll(Collection<?> targets) { 48 return delegate.containsAll(targets); 49 } 50 51 @Override public int size() { 52 return delegate.size(); 53 } 54 55 @Override public boolean isEmpty() { 56 return delegate.isEmpty(); 57 } 58 59 @Override public Object[] toArray() { 60 return delegate.toArray(); 61 } 62 63 @Override public <T> T[] toArray(T[] other) { 64 return delegate.toArray(other); 65 } 66 67 @Override public String toString() { 68 return delegate.toString(); 69 } 70 71 // TODO(cpovirk): equals(), as well, in case it's any faster than Sets.equalsImpl? 72 73 @Override public int hashCode() { 74 return delegate.hashCode(); 75 } 76} 77