com.google.common.collect.ForwardingDeque Maven / Gradle / Ivy
/*
* Copyright (C) 2012 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.GwtIncompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Deque;
import java.util.Iterator;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* A deque which forwards all its method calls to another deque. Subclasses should override one or
* more methods to modify the behavior of the backing deque as desired per the decorator pattern.
*
* Warning: The methods of {@code ForwardingDeque} forward indiscriminately to the
* methods of the delegate. For example, overriding {@link #add} alone will not change the
* behavior of {@link #offer} which can lead to unexpected behavior. In this case, you should
* override {@code offer} as well.
*
*
{@code default} method warning: This class does not forward calls to {@code
* default} methods. Instead, it inherits their default implementations. When those implementations
* invoke methods, they invoke methods on the {@code ForwardingDeque}.
*
* @author Kurt Alfred Kluever
* @since 12.0
*/
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class ForwardingDeque extends ForwardingQueue
implements Deque {
/** Constructor for use by subclasses. */
protected ForwardingDeque() {}
@Override
protected abstract Deque delegate();
@Override
public void addFirst(@ParametricNullness E e) {
delegate().addFirst(e);
}
@Override
public void addLast(@ParametricNullness E e) {
delegate().addLast(e);
}
@Override
public Iterator descendingIterator() {
return delegate().descendingIterator();
}
@Override
@ParametricNullness
public E getFirst() {
return delegate().getFirst();
}
@Override
@ParametricNullness
public E getLast() {
return delegate().getLast();
}
@CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
@Override
public boolean offerFirst(@ParametricNullness E e) {
return delegate().offerFirst(e);
}
@CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
@Override
public boolean offerLast(@ParametricNullness E e) {
return delegate().offerLast(e);
}
@Override
@CheckForNull
public E peekFirst() {
return delegate().peekFirst();
}
@Override
@CheckForNull
public E peekLast() {
return delegate().peekLast();
}
@CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
@Override
@CheckForNull
public E pollFirst() {
return delegate().pollFirst();
}
@CanIgnoreReturnValue // TODO(cpovirk): Consider removing this?
@Override
@CheckForNull
public E pollLast() {
return delegate().pollLast();
}
@CanIgnoreReturnValue
@Override
@ParametricNullness
public E pop() {
return delegate().pop();
}
@Override
public void push(@ParametricNullness E e) {
delegate().push(e);
}
@CanIgnoreReturnValue
@Override
@ParametricNullness
public E removeFirst() {
return delegate().removeFirst();
}
@CanIgnoreReturnValue
@Override
@ParametricNullness
public E removeLast() {
return delegate().removeLast();
}
@CanIgnoreReturnValue
@Override
public boolean removeFirstOccurrence(@CheckForNull Object o) {
return delegate().removeFirstOccurrence(o);
}
@CanIgnoreReturnValue
@Override
public boolean removeLastOccurrence(@CheckForNull Object o) {
return delegate().removeLastOccurrence(o);
}
}