com.google.gwt.emul.java.util.EnumMap Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* 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 java.util;
import com.google.gwt.lang.Array;
/**
* A {@link java.util.Map} of {@link Enum}s. [Sun
* docs]
*
* @param key type
* @param value type
*/
public class EnumMap, V> extends AbstractMap {
private final class EntrySet extends AbstractSet> {
@Override
public void clear() {
EnumMap.this.clear();
}
@Override
public boolean contains(Object o) {
if (o instanceof Map.Entry) {
Map.Entry entry = (Map.Entry) o;
Object key = entry.getKey();
if (EnumMap.this.containsKey(key)) {
Object value = EnumMap.this.get(key);
return Objects.equals(entry.getValue(), value);
}
}
return false;
}
@Override
public Iterator> iterator() {
return new EntrySetIterator();
}
@Override
public boolean remove(Object entry) {
if (contains(entry)) {
Object key = ((Map.Entry) entry).getKey();
EnumMap.this.remove(key);
return true;
}
return false;
}
public int size() {
return EnumMap.this.size();
}
}
private final class EntrySetIterator implements Iterator> {
private Iterator it = keySet.iterator();
private K key;
public boolean hasNext() {
return it.hasNext();
}
public Entry next() {
key = it.next();
return new MapEntry(key);
}
public void remove() {
if (key == null) {
throw new IllegalStateException();
}
EnumMap.this.remove(key);
key = null;
}
}
private class MapEntry extends AbstractMapEntry {
private final K key;
public MapEntry(K key) {
this.key = key;
}
public K getKey() {
return key;
}
public V getValue() {
return values[key.ordinal()];
}
public V setValue(V value) {
V old = getValue();
values[key.ordinal()] = value;
return old;
}
}
private EnumSet keySet;
private V[] values;
public EnumMap(Class type) {
init(type);
}
public EnumMap(EnumMap m) {
init(m);
}
public EnumMap(Map m) {
if (m instanceof EnumMap) {
init((EnumMap) m);
} else {
if (m.isEmpty()) {
throw new IllegalArgumentException("Specified map is empty");
}
init(m.keySet().iterator().next().getDeclaringClass());
putAll(m);
}
}
@SuppressWarnings("unchecked")
@Override
public void clear() {
keySet.clear();
values = (V[]) new Object[values.length];
}
public EnumMap clone() {
return new EnumMap(this);
}
@Override
public boolean containsKey(Object key) {
return keySet.contains(key);
}
@Override
public boolean containsValue(Object value) {
for (K key : keySet) {
if (Objects.equals(value, values[key.ordinal()])) {
return true;
}
}
return false;
}
@Override
public Set> entrySet() {
return new EntrySet();
}
@Override
public V get(Object k) {
return keySet.contains(k) ? values[asOrdinal(k)] : null;
}
@Override
public V put(K key, V value) {
keySet.add(key);
return set(key.ordinal(), value);
}
@Override
public V remove(Object key) {
return keySet.remove(key) ? set(asOrdinal(key), null) : null;
}
@Override
public int size() {
return keySet.size();
}
/**
* Returns key as K. Only runtime checks that
* key is an Enum, not that it's the particular Enum K. Should only be called
* when you are sure key is of type K.
*/
@SuppressWarnings("unchecked")
private K asKey(Object key) {
return (K) key;
}
private int asOrdinal(Object key) {
return asKey(key).ordinal();
}
@SuppressWarnings("unchecked")
private void init(Class type) {
keySet = EnumSet.noneOf(type);
values = (V[]) new Object[keySet.capacity()];
}
private void init(EnumMap m) {
keySet = m.keySet.clone();
values = Array.clone(m.values);
}
private V set(int ordinal, V value) {
V was = values[ordinal];
values[ordinal] = value;
return was;
}
}