eaglercraft-1.8/sources/main/java/com/google/common/collect/WellBehavedMap.java
2022-12-25 01:12:28 -08:00

102 lines
2.5 KiB
Java

/*
* Copyright (C) 2011 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 java.util.Iterator;
import java.util.Map;
import java.util.Set;
import com.google.common.annotations.GwtCompatible;
/**
* Workaround for
* <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6312706"> EnumMap
* bug</a>. If you want to pass an {@code EnumMap}, with the intention of using
* its {@code entrySet()} method, you should wrap the {@code EnumMap} in this
* class instead.
*
* <p>
* This class is not thread-safe even if the underlying map is.
*
* @author Dimitris Andreou
*/
@GwtCompatible
final class WellBehavedMap<K, V> extends ForwardingMap<K, V> {
private final Map<K, V> delegate;
private Set<Entry<K, V>> entrySet;
private WellBehavedMap(Map<K, V> delegate) {
this.delegate = delegate;
}
/**
* Wraps the given map into a {@code WellBehavedEntriesMap}, which intercepts
* its {@code entrySet()} method by taking the {@code Set<K> keySet()} and
* transforming it to {@code Set<Entry<K, V>>}. All other invocations are
* delegated as-is.
*/
static <K, V> WellBehavedMap<K, V> wrap(Map<K, V> delegate) {
return new WellBehavedMap<K, V>(delegate);
}
@Override
protected Map<K, V> delegate() {
return delegate;
}
@Override
public Set<Entry<K, V>> entrySet() {
Set<Entry<K, V>> es = entrySet;
if (es != null) {
return es;
}
return entrySet = new EntrySet();
}
private final class EntrySet extends Maps.EntrySet<K, V> {
@Override
Map<K, V> map() {
return WellBehavedMap.this;
}
@Override
public Iterator<Entry<K, V>> iterator() {
return new TransformedIterator<K, Entry<K, V>>(keySet().iterator()) {
@Override
Entry<K, V> transform(final K key) {
return new AbstractMapEntry<K, V>() {
@Override
public K getKey() {
return key;
}
@Override
public V getValue() {
return get(key);
}
@Override
public V setValue(V value) {
return put(key, value);
}
};
}
};
}
}
}