| /* |
| * 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 static com.google.common.base.Preconditions.checkNotNull; |
| |
| import java.io.Serializable; |
| import java.util.AbstractCollection; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.Spliterator; |
| import org.checkerframework.checker.nullness.qual.Nullable; |
| |
| /** |
| * GWT emulated version of {@link ImmutableCollection}. |
| * |
| * @author Jesse Wilson |
| */ |
| @SuppressWarnings("serial") // we're overriding default serialization |
| public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable { |
| static final int SPLITERATOR_CHARACTERISTICS = |
| Spliterator.IMMUTABLE | Spliterator.NONNULL | Spliterator.ORDERED; |
| |
| static final ImmutableCollection<Object> EMPTY_IMMUTABLE_COLLECTION = |
| new ForwardingImmutableCollection<Object>(Collections.emptyList()); |
| |
| ImmutableCollection() {} |
| |
| public abstract UnmodifiableIterator<E> iterator(); |
| |
| public boolean contains(@Nullable Object object) { |
| return object != null && super.contains(object); |
| } |
| |
| public final boolean add(E e) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public final boolean remove(Object object) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public final boolean addAll(Collection<? extends E> newElements) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public final boolean removeAll(Collection<?> oldElements) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public final boolean retainAll(Collection<?> elementsToKeep) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public final void clear() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| private transient ImmutableList<E> asList; |
| |
| public ImmutableList<E> asList() { |
| ImmutableList<E> list = asList; |
| return (list == null) ? (asList = createAsList()) : list; |
| } |
| |
| ImmutableList<E> createAsList() { |
| switch (size()) { |
| case 0: |
| return ImmutableList.of(); |
| case 1: |
| return ImmutableList.of(iterator().next()); |
| default: |
| return new RegularImmutableAsList<E>(this, toArray()); |
| } |
| } |
| |
| /** If this collection is backed by an array of its elements in insertion order, returns it. */ |
| @Nullable |
| Object[] internalArray() { |
| return null; |
| } |
| |
| /** |
| * If this collection is backed by an array of its elements in insertion order, returns the offset |
| * where this collection's elements start. |
| */ |
| int internalArrayStart() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| /** |
| * If this collection is backed by an array of its elements in insertion order, returns the offset |
| * where this collection's elements end. |
| */ |
| int internalArrayEnd() { |
| throw new UnsupportedOperationException(); |
| } |
| |
| static <E> ImmutableCollection<E> unsafeDelegate(Collection<E> delegate) { |
| return new ForwardingImmutableCollection<E>(delegate); |
| } |
| |
| boolean isPartialView() { |
| return false; |
| } |
| |
| /** GWT emulated version of {@link ImmutableCollection.Builder}. */ |
| public abstract static class Builder<E> { |
| |
| Builder() {} |
| |
| static int expandedCapacity(int oldCapacity, int minCapacity) { |
| if (minCapacity < 0) { |
| throw new AssertionError("cannot store more than MAX_VALUE elements"); |
| } |
| // careful of overflow! |
| int newCapacity = oldCapacity + (oldCapacity >> 1) + 1; |
| if (newCapacity < minCapacity) { |
| newCapacity = Integer.highestOneBit(minCapacity - 1) << 1; |
| } |
| if (newCapacity < 0) { |
| newCapacity = Integer.MAX_VALUE; |
| // guaranteed to be >= newCapacity |
| } |
| return newCapacity; |
| } |
| |
| public abstract Builder<E> add(E element); |
| |
| public Builder<E> add(E... elements) { |
| checkNotNull(elements); // for GWT |
| for (E element : elements) { |
| add(checkNotNull(element)); |
| } |
| return this; |
| } |
| |
| public Builder<E> addAll(Iterable<? extends E> elements) { |
| checkNotNull(elements); // for GWT |
| for (E element : elements) { |
| add(checkNotNull(element)); |
| } |
| return this; |
| } |
| |
| public Builder<E> addAll(Iterator<? extends E> elements) { |
| checkNotNull(elements); // for GWT |
| while (elements.hasNext()) { |
| add(checkNotNull(elements.next())); |
| } |
| return this; |
| } |
| |
| public abstract ImmutableCollection<E> build(); |
| } |
| } |