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
17package com.google.common.collect;
18
19import com.google.common.annotations.GwtCompatible;
20
21import java.util.Collection;
22import java.util.Map;
23import java.util.Set;
24
25import javax.annotation.Nullable;
26
27/**
28 * A map which forwards all its method calls to another map. Subclasses should
29 * override one or more methods to modify the behavior of the backing map as
30 * desired per the <a
31 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
32 *
33 * @see ForwardingObject
34 * @author Kevin Bourrillion
35 * @author Jared Levy
36 * @since 2010.01.04 <b>stable</b> (imported from Google Collections Library)
37 */
38@GwtCompatible
39public abstract class ForwardingMap<K, V> extends ForwardingObject
40    implements Map<K, V> {
41
42  @Override protected abstract Map<K, V> delegate();
43
44  public int size() {
45    return delegate().size();
46  }
47
48  public boolean isEmpty() {
49    return delegate().isEmpty();
50  }
51
52  public V remove(Object object) {
53    return delegate().remove(object);
54  }
55
56  public void clear() {
57    delegate().clear();
58  }
59
60  public boolean containsKey(Object key) {
61    return delegate().containsKey(key);
62  }
63
64  public boolean containsValue(Object value) {
65    return delegate().containsValue(value);
66  }
67
68  public V get(Object key) {
69    return delegate().get(key);
70  }
71
72  public V put(K key, V value) {
73    return delegate().put(key, value);
74  }
75
76  public void putAll(Map<? extends K, ? extends V> map) {
77    delegate().putAll(map);
78  }
79
80  public Set<K> keySet() {
81    return delegate().keySet();
82  }
83
84  public Collection<V> values() {
85    return delegate().values();
86  }
87
88  public Set<Entry<K, V>> entrySet() {
89    return delegate().entrySet();
90  }
91
92  @Override public boolean equals(@Nullable Object object) {
93    return object == this || delegate().equals(object);
94  }
95
96  @Override public int hashCode() {
97    return delegate().hashCode();
98  }
99}
100