| /* |
| * Copyright (C) 2008 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.google.common.collect; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.common.annotations.GwtIncompatible; |
| import java.io.Serializable; |
| import org.checkerframework.checker.nullness.compatqual.NullableDecl; |
| |
| /** |
| * {@code keySet()} implementation for {@link ImmutableMap}. |
| * |
| * @author Jesse Wilson |
| * @author Kevin Bourrillion |
| */ |
| @GwtCompatible(emulated = true) |
| final class ImmutableMapKeySet<K, V> extends IndexedImmutableSet<K> { |
| private final ImmutableMap<K, V> map; |
| |
| ImmutableMapKeySet(ImmutableMap<K, V> map) { |
| this.map = map; |
| } |
| |
| @Override |
| public int size() { |
| return map.size(); |
| } |
| |
| @Override |
| public UnmodifiableIterator<K> iterator() { |
| return map.keyIterator(); |
| } |
| |
| @Override |
| public boolean contains(@NullableDecl Object object) { |
| return map.containsKey(object); |
| } |
| |
| @Override |
| K get(int index) { |
| return map.entrySet().asList().get(index).getKey(); |
| } |
| |
| @Override |
| boolean isPartialView() { |
| return true; |
| } |
| |
| @GwtIncompatible // serialization |
| @Override |
| Object writeReplace() { |
| return new KeySetSerializedForm<K>(map); |
| } |
| |
| @GwtIncompatible // serialization |
| private static class KeySetSerializedForm<K> implements Serializable { |
| final ImmutableMap<K, ?> map; |
| |
| KeySetSerializedForm(ImmutableMap<K, ?> map) { |
| this.map = map; |
| } |
| |
| Object readResolve() { |
| return map.keySet(); |
| } |
| |
| private static final long serialVersionUID = 0; |
| } |
| } |