com.google.common.collect.ForwardingListIterator Maven / Gradle / Ivy
/*
* 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.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ListIterator;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* A list iterator which forwards all its method calls to another list iterator. Subclasses should
* override one or more methods to modify the behavior of the backing iterator as desired per the decorator pattern.
*
* {@code default} method warning: This class forwards calls to only some {@code
* default} methods. Specifically, it forwards calls only for methods that existed before {@code
* default} methods were introduced. For newer methods, like {@code forEachRemaining}, it
* inherits their default implementations. When those implementations invoke methods, they invoke
* methods on the {@code ForwardingListIterator}.
*
* @author Mike Bostock
* @since 2.0
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class ForwardingListIterator
extends ForwardingIterator implements ListIterator {
/** Constructor for use by subclasses. */
protected ForwardingListIterator() {}
@Override
protected abstract ListIterator delegate();
@Override
public void add(@ParametricNullness E element) {
delegate().add(element);
}
@Override
public boolean hasPrevious() {
return delegate().hasPrevious();
}
@Override
public int nextIndex() {
return delegate().nextIndex();
}
@CanIgnoreReturnValue
@Override
@ParametricNullness
public E previous() {
return delegate().previous();
}
@Override
public int previousIndex() {
return delegate().previousIndex();
}
@Override
public void set(@ParametricNullness E element) {
delegate().set(element);
}
}