1/* 2 * Copyright (C) 2008 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.checkArgument; 20 21import com.google.common.base.Function; 22import com.google.common.base.Predicate; 23import com.google.common.collect.Maps.EntryTransformer; 24 25import java.io.Serializable; 26import java.util.AbstractSet; 27import java.util.Collection; 28import java.util.Iterator; 29import java.util.Map; 30import java.util.Set; 31import java.util.SortedMap; 32import java.util.SortedSet; 33 34import javax.annotation.Nullable; 35 36/** 37 * Minimal GWT emulation of {@code com.google.common.collect.Platform}. 38 * 39 * <p><strong>This .java file should never be consumed by javac.</strong> 40 * 41 * @author Hayward Chan 42 */ 43final class Platform { 44 45 static <T> T[] newArray(T[] reference, int length) { 46 return GwtPlatform.newArray(reference, length); 47 } 48 49 /* 50 * Regarding newSetForMap() and SetFromMap: 51 * 52 * Written by Doug Lea with assistance from members of JCP JSR-166 53 * Expert Group and released to the public domain, as explained at 54 * http://creativecommons.org/licenses/publicdomain 55 */ 56 57 static <E> Set<E> newSetFromMap(Map<E, Boolean> map) { 58 return new SetFromMap<E>(map); 59 } 60 61 private static class SetFromMap<E> extends AbstractSet<E> 62 implements Set<E>, Serializable { 63 private final Map<E, Boolean> m; // The backing map 64 private transient Set<E> s; // Its keySet 65 66 SetFromMap(Map<E, Boolean> map) { 67 checkArgument(map.isEmpty(), "Map is non-empty"); 68 m = map; 69 s = map.keySet(); 70 } 71 72 @Override public void clear() { 73 m.clear(); 74 } 75 @Override public int size() { 76 return m.size(); 77 } 78 @Override public boolean isEmpty() { 79 return m.isEmpty(); 80 } 81 @Override public boolean contains(Object o) { 82 return m.containsKey(o); 83 } 84 @Override public boolean remove(Object o) { 85 return m.remove(o) != null; 86 } 87 @Override public boolean add(E e) { 88 return m.put(e, Boolean.TRUE) == null; 89 } 90 @Override public Iterator<E> iterator() { 91 return s.iterator(); 92 } 93 @Override public Object[] toArray() { 94 return s.toArray(); 95 } 96 @Override public <T> T[] toArray(T[] a) { 97 return s.toArray(a); 98 } 99 @Override public String toString() { 100 return s.toString(); 101 } 102 @Override public int hashCode() { 103 return s.hashCode(); 104 } 105 @Override public boolean equals(@Nullable Object object) { 106 return this == object || this.s.equals(object); 107 } 108 @Override public boolean containsAll(Collection<?> c) { 109 return s.containsAll(c); 110 } 111 @Override public boolean removeAll(Collection<?> c) { 112 return s.removeAll(c); 113 } 114 @Override public boolean retainAll(Collection<?> c) { 115 return s.retainAll(c); 116 } 117 } 118 119 static MapMaker tryWeakKeys(MapMaker mapMaker) { 120 return mapMaker; 121 } 122 123 static <K, V1, V2> SortedMap<K, V2> mapsTransformEntriesSortedMap( 124 SortedMap<K, V1> fromMap, 125 EntryTransformer<? super K, ? super V1, V2> transformer) { 126 return Maps.transformEntriesIgnoreNavigable(fromMap, transformer); 127 } 128 129 static <K, V> SortedMap<K, V> mapsAsMapSortedSet( 130 SortedSet<K> set, Function<? super K, V> function) { 131 return Maps.asMapSortedIgnoreNavigable(set, function); 132 } 133 134 static <E> SortedSet<E> setsFilterSortedSet( 135 SortedSet<E> unfiltered, Predicate<? super E> predicate) { 136 return Sets.filterSortedIgnoreNavigable(unfiltered, predicate); 137 } 138 139 static <K, V> SortedMap<K, V> mapsFilterSortedMap( 140 SortedMap<K, V> unfiltered, Predicate<? super Map.Entry<K, V>> predicate) { 141 return Maps.filterSortedIgnoreNavigable(unfiltered, predicate); 142 } 143 144 private Platform() {} 145} 146