com.google.common.collect.AbstractIndexedListIterator Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* Copyright (C) 2009 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.checkPositionIndex;
import com.google.common.annotations.GwtCompatible;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import org.checkerframework.checker.nullness.qual.Nullable;
/**
* This class provides a skeletal implementation of the {@link ListIterator} interface across a
* fixed number of elements that may be retrieved by position. It does not support {@link #remove},
* {@link #set}, or {@link #add}.
*
* @author Jared Levy
*/
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractIndexedListIterator
extends UnmodifiableListIterator {
private final int size;
private int position;
/** Returns the element with the specified index. This method is called by {@link #next()}. */
@ParametricNullness
protected abstract E get(int index);
/**
* Constructs an iterator across a sequence of the given size whose initial position is 0. That
* is, the first call to {@link #next()} will return the first element (or throw {@link
* NoSuchElementException} if {@code size} is zero).
*
* @throws IllegalArgumentException if {@code size} is negative
*/
protected AbstractIndexedListIterator(int size) {
this(size, 0);
}
/**
* Constructs an iterator across a sequence of the given size with the given initial position.
* That is, the first call to {@link #nextIndex()} will return {@code position}, and the first
* call to {@link #next()} will return the element at that index, if available. Calls to {@link
* #previous()} can retrieve the preceding {@code position} elements.
*
* @throws IndexOutOfBoundsException if {@code position} is negative or is greater than {@code
* size}
* @throws IllegalArgumentException if {@code size} is negative
*/
protected AbstractIndexedListIterator(int size, int position) {
checkPositionIndex(position, size);
this.size = size;
this.position = position;
}
@Override
public final boolean hasNext() {
return position < size;
}
@Override
@ParametricNullness
public final E next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return get(position++);
}
@Override
public final int nextIndex() {
return position;
}
@Override
public final boolean hasPrevious() {
return position > 0;
}
@Override
@ParametricNullness
public final E previous() {
if (!hasPrevious()) {
throw new NoSuchElementException();
}
return get(--position);
}
@Override
public final int previousIndex() {
return position - 1;
}
}