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.GwtIncompatible;
20
21import javax.annotation.Nullable;
22
23/**
24 * Skeletal implementation of {@link ImmutableSortedSet#descendingSet()}.
25 *
26 * @author Louis Wasserman
27 */
28class DescendingImmutableSortedSet<E> extends ImmutableSortedSet<E> {
29  private final ImmutableSortedSet<E> forward;
30
31  DescendingImmutableSortedSet(ImmutableSortedSet<E> forward) {
32    super(Ordering.from(forward.comparator()).reverse());
33    this.forward = forward;
34  }
35
36  @Override
37  public int size() {
38    return forward.size();
39  }
40
41  @Override
42  public UnmodifiableIterator<E> iterator() {
43    return forward.descendingIterator();
44  }
45
46  @Override
47  ImmutableSortedSet<E> headSetImpl(E toElement, boolean inclusive) {
48    return forward.tailSet(toElement, inclusive).descendingSet();
49  }
50
51  @Override
52  ImmutableSortedSet<E> subSetImpl(
53      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
54    return forward.subSet(toElement, toInclusive, fromElement, fromInclusive).descendingSet();
55  }
56
57  @Override
58  ImmutableSortedSet<E> tailSetImpl(E fromElement, boolean inclusive) {
59    return forward.headSet(fromElement, inclusive).descendingSet();
60  }
61
62  @Override
63  @GwtIncompatible("NavigableSet")
64  public ImmutableSortedSet<E> descendingSet() {
65    return forward;
66  }
67
68  @Override
69  @GwtIncompatible("NavigableSet")
70  public UnmodifiableIterator<E> descendingIterator() {
71    return forward.iterator();
72  }
73
74  @Override
75  @GwtIncompatible("NavigableSet")
76  ImmutableSortedSet<E> createDescendingSet() {
77    throw new AssertionError("should never be called");
78  }
79
80  @Override
81  public E lower(E element) {
82    return forward.higher(element);
83  }
84
85  @Override
86  public E floor(E element) {
87    return forward.ceiling(element);
88  }
89
90  @Override
91  public E ceiling(E element) {
92    return forward.floor(element);
93  }
94
95  @Override
96  public E higher(E element) {
97    return forward.lower(element);
98  }
99
100  @Override
101  int indexOf(@Nullable Object target) {
102    int index = forward.indexOf(target);
103    if (index == -1) {
104      return index;
105    } else {
106      return size() - 1 - index;
107    }
108  }
109
110  @Override
111  boolean isPartialView() {
112    return forward.isPartialView();
113  }
114}
115