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author | Yohann Roussel <yroussel@google.com> | 2014-03-19 16:25:37 +0100 |
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committer | Yohann Roussel <yroussel@google.com> | 2014-03-20 15:13:33 +0100 |
commit | 4eceb95409e844fdc33c9c706e1dc307bfd40303 (patch) | |
tree | ee9f4f3fc79f757c79081c336bce4f1782c6ccd8 /guava/src/com/google/common/collect/ForwardingCollection.java | |
parent | 3d2402901b1a6462e2cf47a6fd09711f327961c3 (diff) | |
download | toolchain_jack-4eceb95409e844fdc33c9c706e1dc307bfd40303.zip toolchain_jack-4eceb95409e844fdc33c9c706e1dc307bfd40303.tar.gz toolchain_jack-4eceb95409e844fdc33c9c706e1dc307bfd40303.tar.bz2 |
Initial Jack import.
Change-Id: I953cf0a520195a7187d791b2885848ad0d5a9b43
Diffstat (limited to 'guava/src/com/google/common/collect/ForwardingCollection.java')
-rw-r--r-- | guava/src/com/google/common/collect/ForwardingCollection.java | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/guava/src/com/google/common/collect/ForwardingCollection.java b/guava/src/com/google/common/collect/ForwardingCollection.java new file mode 100644 index 0000000..a6a46f0 --- /dev/null +++ b/guava/src/com/google/common/collect/ForwardingCollection.java @@ -0,0 +1,265 @@ +/* + * Copyright (C) 2007 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.Beta; +import com.google.common.annotations.GwtCompatible; +import com.google.common.base.Objects; + +import java.util.Collection; +import java.util.Iterator; + +import javax.annotation.Nullable; + +/** + * A collection which forwards all its method calls to another collection. + * Subclasses should override one or more methods to modify the behavior of the + * backing collection as desired per the <a + * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. + * + * <p><b>Warning:</b> The methods of {@code ForwardingCollection} forward + * <b>indiscriminately</b> to the methods of the delegate. For example, + * overriding {@link #add} alone <b>will not</b> change the behavior of {@link + * #addAll}, which can lead to unexpected behavior. In this case, you should + * override {@code addAll} as well, either providing your own implementation, or + * delegating to the provided {@code standardAddAll} method. + * + * <p>The {@code standard} methods are not guaranteed to be thread-safe, even + * when all of the methods that they depend on are thread-safe. + * + * @author Kevin Bourrillion + * @author Louis Wasserman + * @since 2.0 (imported from Google Collections Library) + */ +@GwtCompatible +public abstract class ForwardingCollection<E> extends ForwardingObject + implements Collection<E> { + // TODO(user): identify places where thread safety is actually lost + + /** Constructor for use by subclasses. */ + protected ForwardingCollection() {} + + @Override protected abstract Collection<E> delegate(); + + @Override + public Iterator<E> iterator() { + return delegate().iterator(); + } + + @Override + public int size() { + return delegate().size(); + } + + @Override + public boolean removeAll(Collection<?> collection) { + return delegate().removeAll(collection); + } + + @Override + public boolean isEmpty() { + return delegate().isEmpty(); + } + + @Override + public boolean contains(Object object) { + return delegate().contains(object); + } + + @Override + public boolean add(E element) { + return delegate().add(element); + } + + @Override + public boolean remove(Object object) { + return delegate().remove(object); + } + + @Override + public boolean containsAll(Collection<?> collection) { + return delegate().containsAll(collection); + } + + @Override + public boolean addAll(Collection<? extends E> collection) { + return delegate().addAll(collection); + } + + @Override + public boolean retainAll(Collection<?> collection) { + return delegate().retainAll(collection); + } + + @Override + public void clear() { + delegate().clear(); + } + + @Override + public Object[] toArray() { + return delegate().toArray(); + } + + @Override + public <T> T[] toArray(T[] array) { + return delegate().toArray(array); + } + + /** + * A sensible definition of {@link #contains} in terms of {@link #iterator}. + * If you override {@link #iterator}, you may wish to override {@link + * #contains} to forward to this implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardContains(@Nullable Object object) { + return Iterators.contains(iterator(), object); + } + + /** + * A sensible definition of {@link #containsAll} in terms of {@link #contains} + * . If you override {@link #contains}, you may wish to override {@link + * #containsAll} to forward to this implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardContainsAll(Collection<?> collection) { + for (Object o : collection) { + if (!contains(o)) { + return false; + } + } + return true; + } + + /** + * A sensible definition of {@link #addAll} in terms of {@link #add}. If you + * override {@link #add}, you may wish to override {@link #addAll} to forward + * to this implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardAddAll(Collection<? extends E> collection) { + return Iterators.addAll(this, collection.iterator()); + } + + /** + * A sensible definition of {@link #remove} in terms of {@link #iterator}, + * using the iterator's {@code remove} method. If you override {@link + * #iterator}, you may wish to override {@link #remove} to forward to this + * implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardRemove(@Nullable Object object) { + Iterator<E> iterator = iterator(); + while (iterator.hasNext()) { + if (Objects.equal(iterator.next(), object)) { + iterator.remove(); + return true; + } + } + return false; + } + + /** + * A sensible definition of {@link #removeAll} in terms of {@link #iterator}, + * using the iterator's {@code remove} method. If you override {@link + * #iterator}, you may wish to override {@link #removeAll} to forward to this + * implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardRemoveAll(Collection<?> collection) { + return Iterators.removeAll(iterator(), collection); + } + + /** + * A sensible definition of {@link #retainAll} in terms of {@link #iterator}, + * using the iterator's {@code remove} method. If you override {@link + * #iterator}, you may wish to override {@link #retainAll} to forward to this + * implementation. + * + * @since 7.0 + */ + @Beta protected boolean standardRetainAll(Collection<?> collection) { + return Iterators.retainAll(iterator(), collection); + } + + /** + * A sensible definition of {@link #clear} in terms of {@link #iterator}, + * using the iterator's {@code remove} method. If you override {@link + * #iterator}, you may wish to override {@link #clear} to forward to this + * implementation. + * + * @since 7.0 + */ + @Beta protected void standardClear() { + Iterator<E> iterator = iterator(); + while (iterator.hasNext()) { + iterator.next(); + iterator.remove(); + } + } + + /** + * A sensible definition of {@link #isEmpty} as {@code !iterator().hasNext}. + * If you override {@link #isEmpty}, you may wish to override {@link #isEmpty} + * to forward to this implementation. Alternately, it may be more efficient to + * implement {@code isEmpty} as {@code size() == 0}. + * + * @since 7.0 + */ + @Beta protected boolean standardIsEmpty() { + return !iterator().hasNext(); + } + + /** + * A sensible definition of {@link #toString} in terms of {@link #iterator}. + * If you override {@link #iterator}, you may wish to override {@link + * #toString} to forward to this implementation. + * + * @since 7.0 + */ + @Beta protected String standardToString() { + return Collections2.toStringImpl(this); + } + + /** + * A sensible definition of {@link #toArray()} in terms of {@link + * #toArray(Object[])}. If you override {@link #toArray(Object[])}, you may + * wish to override {@link #toArray} to forward to this implementation. + * + * @since 7.0 + */ + @Beta protected Object[] standardToArray() { + Object[] newArray = new Object[size()]; + return toArray(newArray); + } + + /** + * A sensible definition of {@link #toArray(Object[])} in terms of {@link + * #size} and {@link #iterator}. If you override either of these methods, you + * may wish to override {@link #toArray} to forward to this implementation. + * + * @since 7.0 + */ + @Beta protected <T> T[] standardToArray(T[] array) { + return ObjectArrays.toArrayImpl(this, array); + } +} |