UnmodifiableSortedMultiset.java revision 7dd252788645e940eada959bdde927426e2531c9 
1/*
2 * Copyright (C) 2012 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 com.google.common.annotations.GwtCompatible;
20import com.google.common.collect.Multisets.UnmodifiableMultiset;
21
22import java.util.Collections;
23import java.util.Comparator;
24import java.util.SortedSet;
25
26/**
27 * Implementation of {@link Multisets#unmodifiableSortedMultiset(SortedMultiset)},
28 * split out into its own file so it can be GWT emulated (to deal with the differing
29 * elementSet() types in GWT and non-GWT).
30 *
31 * @author Louis Wasserman
32 */
33@GwtCompatible(emulated = true)
34final class UnmodifiableSortedMultiset<E> extends UnmodifiableMultiset<E> implements
35    SortedMultiset<E> {
36  UnmodifiableSortedMultiset(SortedMultiset<E> delegate) {
37    super(delegate);
38  }
39
40  @Override
41  protected SortedMultiset<E> delegate() {
42    return (SortedMultiset<E>) super.delegate();
43  }
44
45  public Comparator<? super E> comparator() {
46    return delegate().comparator();
47  }
48
49  @Override
50  SortedSet<E> createElementSet() {
51    return Collections.unmodifiableSortedSet(delegate().elementSet());
52  }
53
54  @Override
55  public SortedSet<E> elementSet() {
56    return (SortedSet<E>) super.elementSet();
57  }
58
59  private transient UnmodifiableSortedMultiset<E> descendingMultiset;
60
61  public SortedMultiset<E> descendingMultiset() {
62    UnmodifiableSortedMultiset<E> result = descendingMultiset;
63    if (result == null) {
64      result = new UnmodifiableSortedMultiset<E>(delegate().descendingMultiset());
65      result.descendingMultiset = this;
66      return descendingMultiset = result;
67    }
68    return result;
69  }
70
71  public Entry<E> firstEntry() {
72    return delegate().firstEntry();
73  }
74
75  public Entry<E> lastEntry() {
76    return delegate().lastEntry();
77  }
78
79  public Entry<E> pollFirstEntry() {
80    throw new UnsupportedOperationException();
81  }
82
83  public Entry<E> pollLastEntry() {
84    throw new UnsupportedOperationException();
85  }
86
87  public SortedMultiset<E> headMultiset(E upperBound, BoundType boundType) {
88    return Multisets.unmodifiableSortedMultiset(delegate().headMultiset(upperBound, boundType));
89  }
90
91  public SortedMultiset<E> subMultiset(E lowerBound, BoundType lowerBoundType, E upperBound,
92      BoundType upperBoundType) {
93    return Multisets.unmodifiableSortedMultiset(delegate().subMultiset(lowerBound, lowerBoundType,
94        upperBound, upperBoundType));
95  }
96
97  public SortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
98    return Multisets.unmodifiableSortedMultiset(delegate().tailMultiset(lowerBound, boundType));
99  }
100
101  private static final long serialVersionUID = 0;
102}