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
17package com.google.common.collect;
18
19import static com.google.common.base.Preconditions.checkNotNull;
20
21import com.google.common.annotations.GwtCompatible;
22
23import java.util.Map;
24
25/**
26 * An implementation of {@link ImmutableTable} that holds a single cell.
27 *
28 * @author Gregory Kick
29 */
30@GwtCompatible
31class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
32  final R singleRowKey;
33  final C singleColumnKey;
34  final V singleValue;
35
36  SingletonImmutableTable(R rowKey, C columnKey, V value) {
37    this.singleRowKey = checkNotNull(rowKey);
38    this.singleColumnKey = checkNotNull(columnKey);
39    this.singleValue = checkNotNull(value);
40  }
41
42  SingletonImmutableTable(Cell<R, C, V> cell) {
43    this(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
44  }
45
46  @Override public ImmutableMap<R, V> column(C columnKey) {
47    checkNotNull(columnKey);
48    return containsColumn(columnKey)
49        ? ImmutableMap.of(singleRowKey, singleValue)
50        : ImmutableMap.<R, V>of();
51  }
52
53  @Override public ImmutableMap<C, Map<R, V>> columnMap() {
54    return ImmutableMap.of(singleColumnKey,
55        (Map<R, V>) ImmutableMap.of(singleRowKey, singleValue));
56  }
57
58  @Override public ImmutableMap<R, Map<C, V>> rowMap() {
59    return ImmutableMap.of(singleRowKey,
60        (Map<C, V>) ImmutableMap.of(singleColumnKey, singleValue));
61  }
62
63  @Override public int size() {
64    return 1;
65  }
66
67  @Override
68  ImmutableSet<Cell<R, C, V>> createCellSet() {
69    return ImmutableSet.of(
70        cellOf(singleRowKey, singleColumnKey, singleValue));
71  }
72
73  @Override ImmutableCollection<V> createValues() {
74    return ImmutableSet.of(singleValue);
75  }
76}
77