| /* |
| * 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; |
| |
| /** |
| * 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 <a |
| * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. |
| * |
| * <p><b>Warning:</b> The methods of {@code ForwardingDeque} 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 #offer} which can lead to unexpected behavior. In this case, you should |
| * override {@code offer} as well. |
| * |
| * <p><b>{@code default} method warning:</b> This class does <i>not</i> 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 |
| public abstract class ForwardingDeque<E> extends ForwardingQueue<E> implements Deque<E> { |
| |
| /** Constructor for use by subclasses. */ |
| protected ForwardingDeque() {} |
| |
| @Override |
| protected abstract Deque<E> delegate(); |
| |
| @Override |
| public void addFirst(E e) { |
| delegate().addFirst(e); |
| } |
| |
| @Override |
| public void addLast(E e) { |
| delegate().addLast(e); |
| } |
| |
| @Override |
| public Iterator<E> descendingIterator() { |
| return delegate().descendingIterator(); |
| } |
| |
| @Override |
| public E getFirst() { |
| return delegate().getFirst(); |
| } |
| |
| @Override |
| public E getLast() { |
| return delegate().getLast(); |
| } |
| |
| @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this? |
| @Override |
| public boolean offerFirst(E e) { |
| return delegate().offerFirst(e); |
| } |
| |
| @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this? |
| @Override |
| public boolean offerLast(E e) { |
| return delegate().offerLast(e); |
| } |
| |
| @Override |
| public E peekFirst() { |
| return delegate().peekFirst(); |
| } |
| |
| @Override |
| public E peekLast() { |
| return delegate().peekLast(); |
| } |
| |
| @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this? |
| @Override |
| public E pollFirst() { |
| return delegate().pollFirst(); |
| } |
| |
| @CanIgnoreReturnValue // TODO(cpovirk): Consider removing this? |
| @Override |
| public E pollLast() { |
| return delegate().pollLast(); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public E pop() { |
| return delegate().pop(); |
| } |
| |
| @Override |
| public void push(E e) { |
| delegate().push(e); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public E removeFirst() { |
| return delegate().removeFirst(); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public E removeLast() { |
| return delegate().removeLast(); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public boolean removeFirstOccurrence(Object o) { |
| return delegate().removeFirstOccurrence(o); |
| } |
| |
| @CanIgnoreReturnValue |
| @Override |
| public boolean removeLastOccurrence(Object o) { |
| return delegate().removeLastOccurrence(o); |
| } |
| } |