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  
17  package com.google.common.collect;
18  
19  import com.google.common.annotations.GwtCompatible;
20  
21  /**
22   * List returned by {@link ImmutableCollection#asList} that delegates {@code contains} checks
23   * to the backing collection.
24   *
25   * @author Jared Levy
26   * @author Louis Wasserman
27   */
28  @GwtCompatible(serializable = true, emulated = true)
29  @SuppressWarnings("serial")
30  abstract class ImmutableAsList<E> extends ImmutableList<E> {
31    abstract ImmutableCollection<E> delegateCollection();
32  
33    @Override public boolean contains(Object target) {
34      // The collection's contains() is at least as fast as ImmutableList's
35      // and is often faster.
36      return delegateCollection().contains(target);
37    }
38  
39    @Override
40    public int size() {
41      return delegateCollection().size();
42    }
43  
44    @Override
45    public boolean isEmpty() {
46      return delegateCollection().isEmpty();
47    }
48  
49    @Override
50    boolean isPartialView() {
51      return delegateCollection().isPartialView();
52    }
53  }
54