1   /*
2    * Copyright (C) 2008 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  
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.io.Serializable;
23  import java.util.Map.Entry;
24  
25  import javax.annotation.Nullable;
26  
27  /**
28   * {@code values()} implementation for {@link ImmutableMap}.
29   *
30   * @author Jesse Wilson
31   * @author Kevin Bourrillion
32   */
33  @GwtCompatible(emulated = true)
34  final class ImmutableMapValues<K, V> extends ImmutableCollection<V> {
35    private final ImmutableMap<K, V> map;
36    
37    ImmutableMapValues(ImmutableMap<K, V> map) {
38      this.map = map;
39    }
40  
41    @Override
42    public int size() {
43      return map.size();
44    }
45  
46    @Override
47    public UnmodifiableIterator<V> iterator() {
48      return Maps.valueIterator(map.entrySet().iterator());
49    }
50  
51    @Override
52    public boolean contains(@Nullable Object object) {
53      return object != null && Iterators.contains(iterator(), object);
54    }
55  
56    @Override
57    boolean isPartialView() {
58      return true;
59    }
60  
61    @Override
62    ImmutableList<V> createAsList() {
63      final ImmutableList<Entry<K, V>> entryList = map.entrySet().asList();
64      return new ImmutableAsList<V>() {
65        @Override
66        public V get(int index) {
67          return entryList.get(index).getValue();
68        }
69  
70        @Override
71        ImmutableCollection<V> delegateCollection() {
72          return ImmutableMapValues.this;
73        }
74      };
75    }
76  
77    @GwtIncompatible("serialization")
78    @Override Object writeReplace() {
79      return new SerializedForm<V>(map);
80    }
81  
82    @GwtIncompatible("serialization")
83    private static class SerializedForm<V> implements Serializable {
84      final ImmutableMap<?, V> map;
85      SerializedForm(ImmutableMap<?, V> map) {
86        this.map = map;
87      }
88      Object readResolve() {
89        return map.values();
90      }
91      private static final long serialVersionUID = 0;
92    }
93  }