feat(jdk8): move files to new folder to avoid resources compiled.
This commit is contained in:
541
jdkSrc/jdk8/sun/awt/util/IdentityArrayList.java
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541
jdkSrc/jdk8/sun/awt/util/IdentityArrayList.java
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/*
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* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
|
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
|
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* published by the Free Software Foundation. Oracle designates this
|
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* particular file as subject to the "Classpath" exception as provided
|
||||
* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
|
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
||||
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package sun.awt.util;
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import java.util.AbstractList;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.ConcurrentModificationException;
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import java.util.List;
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import java.util.RandomAccess;
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/**
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* Resizable-array implementation of the <tt>List</tt> interface. Implements
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* all optional list operations, and permits all elements, including
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* <tt>null</tt>. In addition to implementing the <tt>List</tt> interface,
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* this class provides methods to manipulate the size of the array that is
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* used internally to store the list. (This class is roughly equivalent to
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* <tt>Vector</tt>, except that it is unsynchronized.)<p>
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*
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* The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
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* <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
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* time. The <tt>add</tt> operation runs in <i>amortized constant time</i>,
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* that is, adding n elements requires O(n) time. All of the other operations
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* run in linear time (roughly speaking). The constant factor is low compared
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* to that for the <tt>LinkedList</tt> implementation.<p>
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*
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* Each <tt>IdentityArrayList</tt> instance has a <i>capacity</i>. The capacity is
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* the size of the array used to store the elements in the list. It is always
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* at least as large as the list size. As elements are added to an IdentityArrayList,
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* its capacity grows automatically. The details of the growth policy are not
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* specified beyond the fact that adding an element has constant amortized
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* time cost.<p>
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*
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* An application can increase the capacity of an <tt>IdentityArrayList</tt> instance
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* before adding a large number of elements using the <tt>ensureCapacity</tt>
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* operation. This may reduce the amount of incremental reallocation.
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*
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* <p><strong>Note that this implementation is not synchronized.</strong>
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* If multiple threads access an <tt>IdentityArrayList</tt> instance concurrently,
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* and at least one of the threads modifies the list structurally, it
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* <i>must</i> be synchronized externally. (A structural modification is
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* any operation that adds or deletes one or more elements, or explicitly
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* resizes the backing array; merely setting the value of an element is not
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* a structural modification.) This is typically accomplished by
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* synchronizing on some object that naturally encapsulates the list.
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*
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* If no such object exists, the list should be "wrapped" using the
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* {@link Collections#synchronizedList Collections.synchronizedList}
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* method. This is best done at creation time, to prevent accidental
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* unsynchronized access to the list:<pre>
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* List list = Collections.synchronizedList(new IdentityArrayList(...));</pre>
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*
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* <p>The iterators returned by this class's <tt>iterator</tt> and
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* <tt>listIterator</tt> methods are <i>fail-fast</i>: if the list is
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* structurally modified at any time after the iterator is created, in any way
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* except through the iterator's own <tt>remove</tt> or <tt>add</tt> methods,
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* the iterator will throw a {@link ConcurrentModificationException}. Thus, in
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* the face of concurrent modification, the iterator fails quickly and cleanly,
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* rather than risking arbitrary, non-deterministic behavior at an undetermined
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* time in the future.<p>
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*
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* Note that the fail-fast behavior of an iterator cannot be guaranteed
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* as it is, generally speaking, impossible to make any hard guarantees in the
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* presence of unsynchronized concurrent modification. Fail-fast iterators
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* throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
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* Therefore, it would be wrong to write a program that depended on this
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* exception for its correctness: <i>the fail-fast behavior of iterators
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* should be used only to detect bugs.</i><p>
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*
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*/
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public class IdentityArrayList<E> extends AbstractList<E>
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implements List<E>, RandomAccess
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{
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/**
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* The array buffer into which the elements of the IdentityArrayList are stored.
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* The capacity of the IdentityArrayList is the length of this array buffer.
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*/
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private transient Object[] elementData;
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/**
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* The size of the IdentityArrayList (the number of elements it contains).
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*
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* @serial
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*/
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private int size;
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/**
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* Constructs an empty list with the specified initial capacity.
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*
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* @param initialCapacity the initial capacity of the list
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* @exception IllegalArgumentException if the specified initial capacity
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* is negative
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*/
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public IdentityArrayList(int initialCapacity) {
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super();
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if (initialCapacity < 0)
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throw new IllegalArgumentException("Illegal Capacity: "+
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initialCapacity);
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this.elementData = new Object[initialCapacity];
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}
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/**
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* Constructs an empty list with an initial capacity of ten.
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*/
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public IdentityArrayList() {
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this(10);
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}
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/**
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* Constructs a list containing the elements of the specified
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* collection, in the order they are returned by the collection's
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* iterator.
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*
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* @param c the collection whose elements are to be placed into this list
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* @throws NullPointerException if the specified collection is null
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*/
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public IdentityArrayList(Collection<? extends E> c) {
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elementData = c.toArray();
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size = elementData.length;
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// c.toArray might (incorrectly) not return Object[] (see 6260652)
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if (elementData.getClass() != Object[].class)
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elementData = Arrays.copyOf(elementData, size, Object[].class);
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}
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/**
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* Trims the capacity of this <tt>IdentityArrayList</tt> instance to be the
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* list's current size. An application can use this operation to minimize
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* the storage of an <tt>IdentityArrayList</tt> instance.
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*/
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public void trimToSize() {
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modCount++;
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int oldCapacity = elementData.length;
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if (size < oldCapacity) {
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elementData = Arrays.copyOf(elementData, size);
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}
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}
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/**
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* Increases the capacity of this <tt>IdentityArrayList</tt> instance, if
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* necessary, to ensure that it can hold at least the number of elements
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* specified by the minimum capacity argument.
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*
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* @param minCapacity the desired minimum capacity
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*/
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public void ensureCapacity(int minCapacity) {
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modCount++;
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int oldCapacity = elementData.length;
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if (minCapacity > oldCapacity) {
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Object oldData[] = elementData;
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int newCapacity = (oldCapacity * 3)/2 + 1;
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if (newCapacity < minCapacity)
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newCapacity = minCapacity;
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// minCapacity is usually close to size, so this is a win:
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elementData = Arrays.copyOf(elementData, newCapacity);
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}
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}
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/**
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* Returns the number of elements in this list.
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*
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* @return the number of elements in this list
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*/
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public int size() {
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return size;
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}
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/**
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* Returns <tt>true</tt> if this list contains no elements.
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*
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* @return <tt>true</tt> if this list contains no elements
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*/
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public boolean isEmpty() {
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return size == 0;
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}
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||||
|
||||
/**
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* Returns <tt>true</tt> if this list contains the specified element.
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* More formally, returns <tt>true</tt> if and only if this list contains
|
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* at least one element <tt>e</tt> such that
|
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* <tt>(o==null ? e==null : o == e)</tt>.
|
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*
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* @param o element whose presence in this list is to be tested
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* @return <tt>true</tt> if this list contains the specified element
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*/
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public boolean contains(Object o) {
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return indexOf(o) >= 0;
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}
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/**
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* Returns the index of the first occurrence of the specified element
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* in this list, or -1 if this list does not contain the element.
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* More formally, returns the lowest index <tt>i</tt> such that
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* <tt>(o==null ? get(i)==null : o == get(i))</tt>,
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* or -1 if there is no such index.
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*/
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public int indexOf(Object o) {
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for (int i = 0; i < size; i++) {
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if (o == elementData[i]) {
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return i;
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}
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}
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return -1;
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}
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/**
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* Returns the index of the last occurrence of the specified element
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* in this list, or -1 if this list does not contain the element.
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* More formally, returns the highest index <tt>i</tt> such that
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* <tt>(o==null ? get(i)==null : o == get(i))</tt>,
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* or -1 if there is no such index.
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*/
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public int lastIndexOf(Object o) {
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for (int i = size-1; i >= 0; i--) {
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if (o == elementData[i]) {
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return i;
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}
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}
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return -1;
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}
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/**
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* Returns an array containing all of the elements in this list
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* in proper sequence (from first to last element).
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*
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* <p>The returned array will be "safe" in that no references to it are
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* maintained by this list. (In other words, this method must allocate
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* a new array). The caller is thus free to modify the returned array.
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*
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* <p>This method acts as bridge between array-based and collection-based
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* APIs.
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*
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* @return an array containing all of the elements in this list in
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* proper sequence
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*/
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public Object[] toArray() {
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return Arrays.copyOf(elementData, size);
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||||
}
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||||
|
||||
/**
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* Returns an array containing all of the elements in this list in proper
|
||||
* sequence (from first to last element); the runtime type of the returned
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||||
* array is that of the specified array. If the list fits in the
|
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* specified array, it is returned therein. Otherwise, a new array is
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||||
* allocated with the runtime type of the specified array and the size of
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||||
* this list.
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*
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* <p>If the list fits in the specified array with room to spare
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||||
* (i.e., the array has more elements than the list), the element in
|
||||
* the array immediately following the end of the collection is set to
|
||||
* <tt>null</tt>. (This is useful in determining the length of the
|
||||
* list <i>only</i> if the caller knows that the list does not contain
|
||||
* any null elements.)
|
||||
*
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* @param a the array into which the elements of the list are to
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||||
* be stored, if it is big enough; otherwise, a new array of the
|
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* same runtime type is allocated for this purpose.
|
||||
* @return an array containing the elements of the list
|
||||
* @throws ArrayStoreException if the runtime type of the specified array
|
||||
* is not a supertype of the runtime type of every element in
|
||||
* this list
|
||||
* @throws NullPointerException if the specified array is null
|
||||
*/
|
||||
public <T> T[] toArray(T[] a) {
|
||||
if (a.length < size)
|
||||
// Make a new array of a's runtime type, but my contents:
|
||||
return (T[]) Arrays.copyOf(elementData, size, a.getClass());
|
||||
System.arraycopy(elementData, 0, a, 0, size);
|
||||
if (a.length > size)
|
||||
a[size] = null;
|
||||
return a;
|
||||
}
|
||||
|
||||
// Positional Access Operations
|
||||
|
||||
/**
|
||||
* Returns the element at the specified position in this list.
|
||||
*
|
||||
* @param index index of the element to return
|
||||
* @return the element at the specified position in this list
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E get(int index) {
|
||||
rangeCheck(index);
|
||||
|
||||
return (E) elementData[index];
|
||||
}
|
||||
|
||||
/**
|
||||
* Replaces the element at the specified position in this list with
|
||||
* the specified element.
|
||||
*
|
||||
* @param index index of the element to replace
|
||||
* @param element element to be stored at the specified position
|
||||
* @return the element previously at the specified position
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E set(int index, E element) {
|
||||
rangeCheck(index);
|
||||
|
||||
E oldValue = (E) elementData[index];
|
||||
elementData[index] = element;
|
||||
return oldValue;
|
||||
}
|
||||
|
||||
/**
|
||||
* Appends the specified element to the end of this list.
|
||||
*
|
||||
* @param e element to be appended to this list
|
||||
* @return <tt>true</tt> (as specified by {@link Collection#add})
|
||||
*/
|
||||
public boolean add(E e) {
|
||||
ensureCapacity(size + 1); // Increments modCount!!
|
||||
elementData[size++] = e;
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the specified element at the specified position in this
|
||||
* list. Shifts the element currently at that position (if any) and
|
||||
* any subsequent elements to the right (adds one to their indices).
|
||||
*
|
||||
* @param index index at which the specified element is to be inserted
|
||||
* @param element element to be inserted
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public void add(int index, E element) {
|
||||
rangeCheckForAdd(index);
|
||||
|
||||
ensureCapacity(size+1); // Increments modCount!!
|
||||
System.arraycopy(elementData, index, elementData, index + 1,
|
||||
size - index);
|
||||
elementData[index] = element;
|
||||
size++;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the element at the specified position in this list.
|
||||
* Shifts any subsequent elements to the left (subtracts one from their
|
||||
* indices).
|
||||
*
|
||||
* @param index the index of the element to be removed
|
||||
* @return the element that was removed from the list
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E remove(int index) {
|
||||
rangeCheck(index);
|
||||
|
||||
modCount++;
|
||||
E oldValue = (E) elementData[index];
|
||||
|
||||
int numMoved = size - index - 1;
|
||||
if (numMoved > 0)
|
||||
System.arraycopy(elementData, index+1, elementData, index,
|
||||
numMoved);
|
||||
elementData[--size] = null; // Let gc do its work
|
||||
|
||||
return oldValue;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the first occurrence of the specified element from this list,
|
||||
* if it is present. If the list does not contain the element, it is
|
||||
* unchanged. More formally, removes the element with the lowest index
|
||||
* <tt>i</tt> such that
|
||||
* <tt>(o==null ? get(i)==null : o == get(i))</tt>
|
||||
* (if such an element exists). Returns <tt>true</tt> if this list
|
||||
* contained the specified element (or equivalently, if this list
|
||||
* changed as a result of the call).
|
||||
*
|
||||
* @param o element to be removed from this list, if present
|
||||
* @return <tt>true</tt> if this list contained the specified element
|
||||
*/
|
||||
public boolean remove(Object o) {
|
||||
for (int index = 0; index < size; index++) {
|
||||
if (o == elementData[index]) {
|
||||
fastRemove(index);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/*
|
||||
* Private remove method that skips bounds checking and does not
|
||||
* return the value removed.
|
||||
*/
|
||||
private void fastRemove(int index) {
|
||||
modCount++;
|
||||
int numMoved = size - index - 1;
|
||||
if (numMoved > 0)
|
||||
System.arraycopy(elementData, index+1, elementData, index,
|
||||
numMoved);
|
||||
elementData[--size] = null; // Let gc do its work
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes all of the elements from this list. The list will
|
||||
* be empty after this call returns.
|
||||
*/
|
||||
public void clear() {
|
||||
modCount++;
|
||||
|
||||
// Let gc do its work
|
||||
for (int i = 0; i < size; i++)
|
||||
elementData[i] = null;
|
||||
|
||||
size = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Appends all of the elements in the specified collection to the end of
|
||||
* this list, in the order that they are returned by the
|
||||
* specified collection's Iterator. The behavior of this operation is
|
||||
* undefined if the specified collection is modified while the operation
|
||||
* is in progress. (This implies that the behavior of this call is
|
||||
* undefined if the specified collection is this list, and this
|
||||
* list is nonempty.)
|
||||
*
|
||||
* @param c collection containing elements to be added to this list
|
||||
* @return <tt>true</tt> if this list changed as a result of the call
|
||||
* @throws NullPointerException if the specified collection is null
|
||||
*/
|
||||
public boolean addAll(Collection<? extends E> c) {
|
||||
Object[] a = c.toArray();
|
||||
int numNew = a.length;
|
||||
ensureCapacity(size + numNew); // Increments modCount
|
||||
System.arraycopy(a, 0, elementData, size, numNew);
|
||||
size += numNew;
|
||||
return numNew != 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts all of the elements in the specified collection into this
|
||||
* list, starting at the specified position. Shifts the element
|
||||
* currently at that position (if any) and any subsequent elements to
|
||||
* the right (increases their indices). The new elements will appear
|
||||
* in the list in the order that they are returned by the
|
||||
* specified collection's iterator.
|
||||
*
|
||||
* @param index index at which to insert the first element from the
|
||||
* specified collection
|
||||
* @param c collection containing elements to be added to this list
|
||||
* @return <tt>true</tt> if this list changed as a result of the call
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
* @throws NullPointerException if the specified collection is null
|
||||
*/
|
||||
public boolean addAll(int index, Collection<? extends E> c) {
|
||||
rangeCheckForAdd(index);
|
||||
|
||||
Object[] a = c.toArray();
|
||||
int numNew = a.length;
|
||||
ensureCapacity(size + numNew); // Increments modCount
|
||||
|
||||
int numMoved = size - index;
|
||||
if (numMoved > 0) {
|
||||
System.arraycopy(elementData, index, elementData, index + numNew, numMoved);
|
||||
}
|
||||
|
||||
System.arraycopy(a, 0, elementData, index, numNew);
|
||||
size += numNew;
|
||||
return numNew != 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes from this list all of the elements whose index is between
|
||||
* <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive.
|
||||
* Shifts any succeeding elements to the left (reduces their index).
|
||||
* This call shortens the list by <tt>(toIndex - fromIndex)</tt> elements.
|
||||
* (If <tt>toIndex==fromIndex</tt>, this operation has no effect.)
|
||||
*
|
||||
* @param fromIndex index of first element to be removed
|
||||
* @param toIndex index after last element to be removed
|
||||
* @throws IndexOutOfBoundsException if fromIndex or toIndex out of
|
||||
* range (fromIndex < 0 || fromIndex >= size() || toIndex
|
||||
* > size() || toIndex < fromIndex)
|
||||
*/
|
||||
protected void removeRange(int fromIndex, int toIndex) {
|
||||
modCount++;
|
||||
int numMoved = size - toIndex;
|
||||
System.arraycopy(elementData, toIndex, elementData, fromIndex,
|
||||
numMoved);
|
||||
|
||||
// Let gc do its work
|
||||
int newSize = size - (toIndex-fromIndex);
|
||||
while (size != newSize)
|
||||
elementData[--size] = null;
|
||||
}
|
||||
|
||||
/**
|
||||
* Checks if the given index is in range. If not, throws an appropriate
|
||||
* runtime exception. This method does *not* check if the index is
|
||||
* negative: It is always used immediately prior to an array access,
|
||||
* which throws an ArrayIndexOutOfBoundsException if index is negative.
|
||||
*/
|
||||
private void rangeCheck(int index) {
|
||||
if (index >= size)
|
||||
throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
|
||||
}
|
||||
|
||||
/**
|
||||
* A version of rangeCheck used by add and addAll.
|
||||
*/
|
||||
private void rangeCheckForAdd(int index) {
|
||||
if (index > size || index < 0)
|
||||
throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
|
||||
}
|
||||
|
||||
/**
|
||||
* Constructs an IndexOutOfBoundsException detail message.
|
||||
* Of the many possible refactorings of the error handling code,
|
||||
* this "outlining" performs best with both server and client VMs.
|
||||
*/
|
||||
private String outOfBoundsMsg(int index) {
|
||||
return "Index: "+index+", Size: "+size;
|
||||
}
|
||||
}
|
||||
877
jdkSrc/jdk8/sun/awt/util/IdentityLinkedList.java
Normal file
877
jdkSrc/jdk8/sun/awt/util/IdentityLinkedList.java
Normal file
@@ -0,0 +1,877 @@
|
||||
/*
|
||||
* Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
|
||||
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
||||
*
|
||||
* This code is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 only, as
|
||||
* published by the Free Software Foundation. Oracle designates this
|
||||
* particular file as subject to the "Classpath" exception as provided
|
||||
* by Oracle in the LICENSE file that accompanied this code.
|
||||
*
|
||||
* This code is distributed in the hope that it will be useful, but WITHOUT
|
||||
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||||
* version 2 for more details (a copy is included in the LICENSE file that
|
||||
* accompanied this code).
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License version
|
||||
* 2 along with this work; if not, write to the Free Software Foundation,
|
||||
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
*
|
||||
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
||||
* or visit www.oracle.com if you need additional information or have any
|
||||
* questions.
|
||||
*/
|
||||
|
||||
package sun.awt.util;
|
||||
|
||||
import java.util.AbstractSequentialList;
|
||||
import java.util.Collection;
|
||||
import java.util.ConcurrentModificationException;
|
||||
import java.util.Deque;
|
||||
import java.util.Iterator;
|
||||
import java.util.List;
|
||||
import java.util.ListIterator;
|
||||
import java.util.NoSuchElementException;
|
||||
|
||||
/**
|
||||
* Linked list implementation of the <tt>List</tt> interface. Implements all
|
||||
* optional list operations, and permits all elements (including
|
||||
* <tt>null</tt>). In addition to implementing the <tt>List</tt> interface,
|
||||
* the <tt>IdentityLinkedList</tt> class provides uniformly named methods to
|
||||
* <tt>get</tt>, <tt>remove</tt> and <tt>insert</tt> an element at the
|
||||
* beginning and end of the list. These operations allow linked lists to be
|
||||
* used as a stack, {@linkplain Queue queue}, or {@linkplain Deque
|
||||
* double-ended queue}. <p>
|
||||
*
|
||||
* The class implements the <tt>Deque</tt> interface, providing
|
||||
* first-in-first-out queue operations for <tt>add</tt>,
|
||||
* <tt>poll</tt>, along with other stack and deque operations.<p>
|
||||
*
|
||||
* All of the operations perform as could be expected for a doubly-linked
|
||||
* list. Operations that index into the list will traverse the list from
|
||||
* the beginning or the end, whichever is closer to the specified index.<p>
|
||||
*
|
||||
* <p><strong>Note that this implementation is not synchronized.</strong>
|
||||
* If multiple threads access a linked list concurrently, and at least
|
||||
* one of the threads modifies the list structurally, it <i>must</i> be
|
||||
* synchronized externally. (A structural modification is any operation
|
||||
* that adds or deletes one or more elements; merely setting the value of
|
||||
* an element is not a structural modification.) This is typically
|
||||
* accomplished by synchronizing on some object that naturally
|
||||
* encapsulates the list.
|
||||
*
|
||||
* If no such object exists, the list should be "wrapped" using the
|
||||
* {@link Collections#synchronizedList Collections.synchronizedList}
|
||||
* method. This is best done at creation time, to prevent accidental
|
||||
* unsynchronized access to the list:<pre>
|
||||
* List list = Collections.synchronizedList(new IdentityLinkedList(...));</pre>
|
||||
*
|
||||
* <p>The iterators returned by this class's <tt>iterator</tt> and
|
||||
* <tt>listIterator</tt> methods are <i>fail-fast</i>: if the list is
|
||||
* structurally modified at any time after the iterator is created, in
|
||||
* any way except through the Iterator's own <tt>remove</tt> or
|
||||
* <tt>add</tt> methods, the iterator will throw a {@link
|
||||
* ConcurrentModificationException}. Thus, in the face of concurrent
|
||||
* modification, the iterator fails quickly and cleanly, rather than
|
||||
* risking arbitrary, non-deterministic behavior at an undetermined
|
||||
* time in the future.
|
||||
*
|
||||
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
|
||||
* as it is, generally speaking, impossible to make any hard guarantees in the
|
||||
* presence of unsynchronized concurrent modification. Fail-fast iterators
|
||||
* throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
|
||||
* Therefore, it would be wrong to write a program that depended on this
|
||||
* exception for its correctness: <i>the fail-fast behavior of iterators
|
||||
* should be used only to detect bugs.</i>
|
||||
*/
|
||||
|
||||
public class IdentityLinkedList<E>
|
||||
extends AbstractSequentialList<E>
|
||||
implements List<E>, Deque<E>
|
||||
{
|
||||
private transient Entry<E> header = new Entry<E>(null, null, null);
|
||||
private transient int size = 0;
|
||||
|
||||
/**
|
||||
* Constructs an empty list.
|
||||
*/
|
||||
public IdentityLinkedList() {
|
||||
header.next = header.previous = header;
|
||||
}
|
||||
|
||||
/**
|
||||
* Constructs a list containing the elements of the specified
|
||||
* collection, in the order they are returned by the collection's
|
||||
* iterator.
|
||||
*
|
||||
* @param c the collection whose elements are to be placed into this list
|
||||
* @throws NullPointerException if the specified collection is null
|
||||
*/
|
||||
public IdentityLinkedList(Collection<? extends E> c) {
|
||||
this();
|
||||
addAll(c);
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the first element in this list.
|
||||
*
|
||||
* @return the first element in this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
*/
|
||||
public E getFirst() {
|
||||
if (size==0)
|
||||
throw new NoSuchElementException();
|
||||
|
||||
return header.next.element;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the last element in this list.
|
||||
*
|
||||
* @return the last element in this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
*/
|
||||
public E getLast() {
|
||||
if (size==0)
|
||||
throw new NoSuchElementException();
|
||||
|
||||
return header.previous.element;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes and returns the first element from this list.
|
||||
*
|
||||
* @return the first element from this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
*/
|
||||
public E removeFirst() {
|
||||
return remove(header.next);
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes and returns the last element from this list.
|
||||
*
|
||||
* @return the last element from this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
*/
|
||||
public E removeLast() {
|
||||
return remove(header.previous);
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the specified element at the beginning of this list.
|
||||
*
|
||||
* @param e the element to add
|
||||
*/
|
||||
public void addFirst(E e) {
|
||||
addBefore(e, header.next);
|
||||
}
|
||||
|
||||
/**
|
||||
* Appends the specified element to the end of this list.
|
||||
*
|
||||
* <p>This method is equivalent to {@link #add}.
|
||||
*
|
||||
* @param e the element to add
|
||||
*/
|
||||
public void addLast(E e) {
|
||||
addBefore(e, header);
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns <tt>true</tt> if this list contains the specified element.
|
||||
* More formally, returns <tt>true</tt> if and only if this list contains
|
||||
* at least one element <tt>e</tt> such that
|
||||
* <tt>(o==null ? e==null : o == e)</tt>.
|
||||
*
|
||||
* @param o element whose presence in this list is to be tested
|
||||
* @return <tt>true</tt> if this list contains the specified element
|
||||
*/
|
||||
public boolean contains(Object o) {
|
||||
return indexOf(o) != -1;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the number of elements in this list.
|
||||
*
|
||||
* @return the number of elements in this list
|
||||
*/
|
||||
public int size() {
|
||||
return size;
|
||||
}
|
||||
|
||||
/**
|
||||
* Appends the specified element to the end of this list.
|
||||
*
|
||||
* <p>This method is equivalent to {@link #addLast}.
|
||||
*
|
||||
* @param e element to be appended to this list
|
||||
* @return <tt>true</tt> (as specified by {@link Collection#add})
|
||||
*/
|
||||
public boolean add(E e) {
|
||||
addBefore(e, header);
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the first occurrence of the specified element from this list,
|
||||
* if it is present. If this list does not contain the element, it is
|
||||
* unchanged. More formally, removes the element with the lowest index
|
||||
* <tt>i</tt> such that <tt>get(i)==o</tt>
|
||||
* (if such an element exists). Returns <tt>true</tt> if this list
|
||||
* contained the specified element (or equivalently, if this list
|
||||
* changed as a result of the call).
|
||||
*
|
||||
* @param o element to be removed from this list, if present
|
||||
* @return <tt>true</tt> if this list contained the specified element
|
||||
*/
|
||||
public boolean remove(Object o) {
|
||||
for (Entry<E> e = header.next; e != header; e = e.next) {
|
||||
if (o == e.element) {
|
||||
remove(e);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* Appends all of the elements in the specified collection to the end of
|
||||
* this list, in the order that they are returned by the specified
|
||||
* collection's iterator. The behavior of this operation is undefined if
|
||||
* the specified collection is modified while the operation is in
|
||||
* progress. (Note that this will occur if the specified collection is
|
||||
* this list, and it's nonempty.)
|
||||
*
|
||||
* @param c collection containing elements to be added to this list
|
||||
* @return <tt>true</tt> if this list changed as a result of the call
|
||||
* @throws NullPointerException if the specified collection is null
|
||||
*/
|
||||
public boolean addAll(Collection<? extends E> c) {
|
||||
return addAll(size, c);
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts all of the elements in the specified collection into this
|
||||
* list, starting at the specified position. Shifts the element
|
||||
* currently at that position (if any) and any subsequent elements to
|
||||
* the right (increases their indices). The new elements will appear
|
||||
* in the list in the order that they are returned by the
|
||||
* specified collection's iterator.
|
||||
*
|
||||
* @param index index at which to insert the first element
|
||||
* from the specified collection
|
||||
* @param c collection containing elements to be added to this list
|
||||
* @return <tt>true</tt> if this list changed as a result of the call
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
* @throws NullPointerException if the specified collection is null
|
||||
*/
|
||||
public boolean addAll(int index, Collection<? extends E> c) {
|
||||
if (index < 0 || index > size)
|
||||
throw new IndexOutOfBoundsException("Index: "+index+
|
||||
", Size: "+size);
|
||||
Object[] a = c.toArray();
|
||||
int numNew = a.length;
|
||||
if (numNew==0)
|
||||
return false;
|
||||
modCount++;
|
||||
|
||||
Entry<E> successor = (index==size ? header : entry(index));
|
||||
Entry<E> predecessor = successor.previous;
|
||||
for (int i=0; i<numNew; i++) {
|
||||
Entry<E> e = new Entry<E>((E)a[i], successor, predecessor);
|
||||
predecessor.next = e;
|
||||
predecessor = e;
|
||||
}
|
||||
successor.previous = predecessor;
|
||||
|
||||
size += numNew;
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes all of the elements from this list.
|
||||
*/
|
||||
public void clear() {
|
||||
Entry<E> e = header.next;
|
||||
while (e != header) {
|
||||
Entry<E> next = e.next;
|
||||
e.next = e.previous = null;
|
||||
e.element = null;
|
||||
e = next;
|
||||
}
|
||||
header.next = header.previous = header;
|
||||
size = 0;
|
||||
modCount++;
|
||||
}
|
||||
|
||||
|
||||
// Positional Access Operations
|
||||
|
||||
/**
|
||||
* Returns the element at the specified position in this list.
|
||||
*
|
||||
* @param index index of the element to return
|
||||
* @return the element at the specified position in this list
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E get(int index) {
|
||||
return entry(index).element;
|
||||
}
|
||||
|
||||
/**
|
||||
* Replaces the element at the specified position in this list with the
|
||||
* specified element.
|
||||
*
|
||||
* @param index index of the element to replace
|
||||
* @param element element to be stored at the specified position
|
||||
* @return the element previously at the specified position
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E set(int index, E element) {
|
||||
Entry<E> e = entry(index);
|
||||
E oldVal = e.element;
|
||||
e.element = element;
|
||||
return oldVal;
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the specified element at the specified position in this list.
|
||||
* Shifts the element currently at that position (if any) and any
|
||||
* subsequent elements to the right (adds one to their indices).
|
||||
*
|
||||
* @param index index at which the specified element is to be inserted
|
||||
* @param element element to be inserted
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public void add(int index, E element) {
|
||||
addBefore(element, (index==size ? header : entry(index)));
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the element at the specified position in this list. Shifts any
|
||||
* subsequent elements to the left (subtracts one from their indices).
|
||||
* Returns the element that was removed from the list.
|
||||
*
|
||||
* @param index the index of the element to be removed
|
||||
* @return the element previously at the specified position
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
*/
|
||||
public E remove(int index) {
|
||||
return remove(entry(index));
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the indexed entry.
|
||||
*/
|
||||
private Entry<E> entry(int index) {
|
||||
if (index < 0 || index >= size)
|
||||
throw new IndexOutOfBoundsException("Index: "+index+
|
||||
", Size: "+size);
|
||||
Entry<E> e = header;
|
||||
if (index < (size >> 1)) {
|
||||
for (int i = 0; i <= index; i++)
|
||||
e = e.next;
|
||||
} else {
|
||||
for (int i = size; i > index; i--)
|
||||
e = e.previous;
|
||||
}
|
||||
return e;
|
||||
}
|
||||
|
||||
|
||||
// Search Operations
|
||||
|
||||
/**
|
||||
* Returns the index of the first occurrence of the specified element
|
||||
* in this list, or -1 if this list does not contain the element.
|
||||
* More formally, returns the lowest index <tt>i</tt> such that
|
||||
* <tt>get(i)==o</tt>,
|
||||
* or -1 if there is no such index.
|
||||
*
|
||||
* @param o element to search for
|
||||
* @return the index of the first occurrence of the specified element in
|
||||
* this list, or -1 if this list does not contain the element
|
||||
*/
|
||||
public int indexOf(Object o) {
|
||||
int index = 0;
|
||||
for (Entry e = header.next; e != header; e = e.next) {
|
||||
if (o == e.element) {
|
||||
return index;
|
||||
}
|
||||
index++;
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns the index of the last occurrence of the specified element
|
||||
* in this list, or -1 if this list does not contain the element.
|
||||
* More formally, returns the highest index <tt>i</tt> such that
|
||||
* <tt>get(i)==o</tt>,
|
||||
* or -1 if there is no such index.
|
||||
*
|
||||
* @param o element to search for
|
||||
* @return the index of the last occurrence of the specified element in
|
||||
* this list, or -1 if this list does not contain the element
|
||||
*/
|
||||
public int lastIndexOf(Object o) {
|
||||
int index = size;
|
||||
for (Entry e = header.previous; e != header; e = e.previous) {
|
||||
index--;
|
||||
if (o == e.element) {
|
||||
return index;
|
||||
}
|
||||
}
|
||||
return -1;
|
||||
}
|
||||
|
||||
// Queue operations.
|
||||
|
||||
/**
|
||||
* Retrieves, but does not remove, the head (first element) of this list.
|
||||
* @return the head of this list, or <tt>null</tt> if this list is empty
|
||||
* @since 1.5
|
||||
*/
|
||||
public E peek() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return getFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves, but does not remove, the head (first element) of this list.
|
||||
* @return the head of this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
* @since 1.5
|
||||
*/
|
||||
public E element() {
|
||||
return getFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves and removes the head (first element) of this list
|
||||
* @return the head of this list, or <tt>null</tt> if this list is empty
|
||||
* @since 1.5
|
||||
*/
|
||||
public E poll() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return removeFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves and removes the head (first element) of this list.
|
||||
*
|
||||
* @return the head of this list
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
* @since 1.5
|
||||
*/
|
||||
public E remove() {
|
||||
return removeFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Adds the specified element as the tail (last element) of this list.
|
||||
*
|
||||
* @param e the element to add
|
||||
* @return <tt>true</tt> (as specified by {@link Queue#offer})
|
||||
* @since 1.5
|
||||
*/
|
||||
public boolean offer(E e) {
|
||||
return add(e);
|
||||
}
|
||||
|
||||
// Deque operations
|
||||
/**
|
||||
* Inserts the specified element at the front of this list.
|
||||
*
|
||||
* @param e the element to insert
|
||||
* @return <tt>true</tt> (as specified by {@link Deque#offerFirst})
|
||||
* @since 1.6
|
||||
*/
|
||||
public boolean offerFirst(E e) {
|
||||
addFirst(e);
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Inserts the specified element at the end of this list.
|
||||
*
|
||||
* @param e the element to insert
|
||||
* @return <tt>true</tt> (as specified by {@link Deque#offerLast})
|
||||
* @since 1.6
|
||||
*/
|
||||
public boolean offerLast(E e) {
|
||||
addLast(e);
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves, but does not remove, the first element of this list,
|
||||
* or returns <tt>null</tt> if this list is empty.
|
||||
*
|
||||
* @return the first element of this list, or <tt>null</tt>
|
||||
* if this list is empty
|
||||
* @since 1.6
|
||||
*/
|
||||
public E peekFirst() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return getFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves, but does not remove, the last element of this list,
|
||||
* or returns <tt>null</tt> if this list is empty.
|
||||
*
|
||||
* @return the last element of this list, or <tt>null</tt>
|
||||
* if this list is empty
|
||||
* @since 1.6
|
||||
*/
|
||||
public E peekLast() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return getLast();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves and removes the first element of this list,
|
||||
* or returns <tt>null</tt> if this list is empty.
|
||||
*
|
||||
* @return the first element of this list, or <tt>null</tt> if
|
||||
* this list is empty
|
||||
* @since 1.6
|
||||
*/
|
||||
public E pollFirst() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return removeFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Retrieves and removes the last element of this list,
|
||||
* or returns <tt>null</tt> if this list is empty.
|
||||
*
|
||||
* @return the last element of this list, or <tt>null</tt> if
|
||||
* this list is empty
|
||||
* @since 1.6
|
||||
*/
|
||||
public E pollLast() {
|
||||
if (size==0)
|
||||
return null;
|
||||
return removeLast();
|
||||
}
|
||||
|
||||
/**
|
||||
* Pushes an element onto the stack represented by this list. In other
|
||||
* words, inserts the element at the front of this list.
|
||||
*
|
||||
* <p>This method is equivalent to {@link #addFirst}.
|
||||
*
|
||||
* @param e the element to push
|
||||
* @since 1.6
|
||||
*/
|
||||
public void push(E e) {
|
||||
addFirst(e);
|
||||
}
|
||||
|
||||
/**
|
||||
* Pops an element from the stack represented by this list. In other
|
||||
* words, removes and returns the first element of this list.
|
||||
*
|
||||
* <p>This method is equivalent to {@link #removeFirst()}.
|
||||
*
|
||||
* @return the element at the front of this list (which is the top
|
||||
* of the stack represented by this list)
|
||||
* @throws NoSuchElementException if this list is empty
|
||||
* @since 1.6
|
||||
*/
|
||||
public E pop() {
|
||||
return removeFirst();
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the first occurrence of the specified element in this
|
||||
* list (when traversing the list from head to tail). If the list
|
||||
* does not contain the element, it is unchanged.
|
||||
*
|
||||
* @param o element to be removed from this list, if present
|
||||
* @return <tt>true</tt> if the list contained the specified element
|
||||
* @since 1.6
|
||||
*/
|
||||
public boolean removeFirstOccurrence(Object o) {
|
||||
return remove(o);
|
||||
}
|
||||
|
||||
/**
|
||||
* Removes the last occurrence of the specified element in this
|
||||
* list (when traversing the list from head to tail). If the list
|
||||
* does not contain the element, it is unchanged.
|
||||
*
|
||||
* @param o element to be removed from this list, if present
|
||||
* @return <tt>true</tt> if the list contained the specified element
|
||||
* @since 1.6
|
||||
*/
|
||||
public boolean removeLastOccurrence(Object o) {
|
||||
for (Entry<E> e = header.previous; e != header; e = e.previous) {
|
||||
if (o == e.element) {
|
||||
remove(e);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns a list-iterator of the elements in this list (in proper
|
||||
* sequence), starting at the specified position in the list.
|
||||
* Obeys the general contract of <tt>List.listIterator(int)</tt>.<p>
|
||||
*
|
||||
* The list-iterator is <i>fail-fast</i>: if the list is structurally
|
||||
* modified at any time after the Iterator is created, in any way except
|
||||
* through the list-iterator's own <tt>remove</tt> or <tt>add</tt>
|
||||
* methods, the list-iterator will throw a
|
||||
* <tt>ConcurrentModificationException</tt>. Thus, in the face of
|
||||
* concurrent modification, the iterator fails quickly and cleanly, rather
|
||||
* than risking arbitrary, non-deterministic behavior at an undetermined
|
||||
* time in the future.
|
||||
*
|
||||
* @param index index of the first element to be returned from the
|
||||
* list-iterator (by a call to <tt>next</tt>)
|
||||
* @return a ListIterator of the elements in this list (in proper
|
||||
* sequence), starting at the specified position in the list
|
||||
* @throws IndexOutOfBoundsException {@inheritDoc}
|
||||
* @see List#listIterator(int)
|
||||
*/
|
||||
public ListIterator<E> listIterator(int index) {
|
||||
return new ListItr(index);
|
||||
}
|
||||
|
||||
private class ListItr implements ListIterator<E> {
|
||||
private Entry<E> lastReturned = header;
|
||||
private Entry<E> next;
|
||||
private int nextIndex;
|
||||
private int expectedModCount = modCount;
|
||||
|
||||
ListItr(int index) {
|
||||
if (index < 0 || index > size)
|
||||
throw new IndexOutOfBoundsException("Index: "+index+
|
||||
", Size: "+size);
|
||||
if (index < (size >> 1)) {
|
||||
next = header.next;
|
||||
for (nextIndex=0; nextIndex<index; nextIndex++)
|
||||
next = next.next;
|
||||
} else {
|
||||
next = header;
|
||||
for (nextIndex=size; nextIndex>index; nextIndex--)
|
||||
next = next.previous;
|
||||
}
|
||||
}
|
||||
|
||||
public boolean hasNext() {
|
||||
return nextIndex != size;
|
||||
}
|
||||
|
||||
public E next() {
|
||||
checkForComodification();
|
||||
if (nextIndex == size)
|
||||
throw new NoSuchElementException();
|
||||
|
||||
lastReturned = next;
|
||||
next = next.next;
|
||||
nextIndex++;
|
||||
return lastReturned.element;
|
||||
}
|
||||
|
||||
public boolean hasPrevious() {
|
||||
return nextIndex != 0;
|
||||
}
|
||||
|
||||
public E previous() {
|
||||
if (nextIndex == 0)
|
||||
throw new NoSuchElementException();
|
||||
|
||||
lastReturned = next = next.previous;
|
||||
nextIndex--;
|
||||
checkForComodification();
|
||||
return lastReturned.element;
|
||||
}
|
||||
|
||||
public int nextIndex() {
|
||||
return nextIndex;
|
||||
}
|
||||
|
||||
public int previousIndex() {
|
||||
return nextIndex-1;
|
||||
}
|
||||
|
||||
public void remove() {
|
||||
checkForComodification();
|
||||
Entry<E> lastNext = lastReturned.next;
|
||||
try {
|
||||
IdentityLinkedList.this.remove(lastReturned);
|
||||
} catch (NoSuchElementException e) {
|
||||
throw new IllegalStateException();
|
||||
}
|
||||
if (next==lastReturned)
|
||||
next = lastNext;
|
||||
else
|
||||
nextIndex--;
|
||||
lastReturned = header;
|
||||
expectedModCount++;
|
||||
}
|
||||
|
||||
public void set(E e) {
|
||||
if (lastReturned == header)
|
||||
throw new IllegalStateException();
|
||||
checkForComodification();
|
||||
lastReturned.element = e;
|
||||
}
|
||||
|
||||
public void add(E e) {
|
||||
checkForComodification();
|
||||
lastReturned = header;
|
||||
addBefore(e, next);
|
||||
nextIndex++;
|
||||
expectedModCount++;
|
||||
}
|
||||
|
||||
final void checkForComodification() {
|
||||
if (modCount != expectedModCount)
|
||||
throw new ConcurrentModificationException();
|
||||
}
|
||||
}
|
||||
|
||||
private static class Entry<E> {
|
||||
E element;
|
||||
Entry<E> next;
|
||||
Entry<E> previous;
|
||||
|
||||
Entry(E element, Entry<E> next, Entry<E> previous) {
|
||||
this.element = element;
|
||||
this.next = next;
|
||||
this.previous = previous;
|
||||
}
|
||||
}
|
||||
|
||||
private Entry<E> addBefore(E e, Entry<E> entry) {
|
||||
Entry<E> newEntry = new Entry<E>(e, entry, entry.previous);
|
||||
newEntry.previous.next = newEntry;
|
||||
newEntry.next.previous = newEntry;
|
||||
size++;
|
||||
modCount++;
|
||||
return newEntry;
|
||||
}
|
||||
|
||||
private E remove(Entry<E> e) {
|
||||
if (e == header)
|
||||
throw new NoSuchElementException();
|
||||
|
||||
E result = e.element;
|
||||
e.previous.next = e.next;
|
||||
e.next.previous = e.previous;
|
||||
e.next = e.previous = null;
|
||||
e.element = null;
|
||||
size--;
|
||||
modCount++;
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* @since 1.6
|
||||
*/
|
||||
public Iterator<E> descendingIterator() {
|
||||
return new DescendingIterator();
|
||||
}
|
||||
|
||||
/** Adapter to provide descending iterators via ListItr.previous */
|
||||
private class DescendingIterator implements Iterator {
|
||||
final ListItr itr = new ListItr(size());
|
||||
public boolean hasNext() {
|
||||
return itr.hasPrevious();
|
||||
}
|
||||
public E next() {
|
||||
return itr.previous();
|
||||
}
|
||||
public void remove() {
|
||||
itr.remove();
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns an array containing all of the elements in this list
|
||||
* in proper sequence (from first to last element).
|
||||
*
|
||||
* <p>The returned array will be "safe" in that no references to it are
|
||||
* maintained by this list. (In other words, this method must allocate
|
||||
* a new array). The caller is thus free to modify the returned array.
|
||||
*
|
||||
* <p>This method acts as bridge between array-based and collection-based
|
||||
* APIs.
|
||||
*
|
||||
* @return an array containing all of the elements in this list
|
||||
* in proper sequence
|
||||
*/
|
||||
public Object[] toArray() {
|
||||
Object[] result = new Object[size];
|
||||
int i = 0;
|
||||
for (Entry<E> e = header.next; e != header; e = e.next)
|
||||
result[i++] = e.element;
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns an array containing all of the elements in this list in
|
||||
* proper sequence (from first to last element); the runtime type of
|
||||
* the returned array is that of the specified array. If the list fits
|
||||
* in the specified array, it is returned therein. Otherwise, a new
|
||||
* array is allocated with the runtime type of the specified array and
|
||||
* the size of this list.
|
||||
*
|
||||
* <p>If the list fits in the specified array with room to spare (i.e.,
|
||||
* the array has more elements than the list), the element in the array
|
||||
* immediately following the end of the list is set to <tt>null</tt>.
|
||||
* (This is useful in determining the length of the list <i>only</i> if
|
||||
* the caller knows that the list does not contain any null elements.)
|
||||
*
|
||||
* <p>Like the {@link #toArray()} method, this method acts as bridge between
|
||||
* array-based and collection-based APIs. Further, this method allows
|
||||
* precise control over the runtime type of the output array, and may,
|
||||
* under certain circumstances, be used to save allocation costs.
|
||||
*
|
||||
* <p>Suppose <tt>x</tt> is a list known to contain only strings.
|
||||
* The following code can be used to dump the list into a newly
|
||||
* allocated array of <tt>String</tt>:
|
||||
*
|
||||
* <pre>
|
||||
* String[] y = x.toArray(new String[0]);</pre>
|
||||
*
|
||||
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
|
||||
* <tt>toArray()</tt>.
|
||||
*
|
||||
* @param a the array into which the elements of the list are to
|
||||
* be stored, if it is big enough; otherwise, a new array of the
|
||||
* same runtime type is allocated for this purpose.
|
||||
* @return an array containing the elements of the list
|
||||
* @throws ArrayStoreException if the runtime type of the specified array
|
||||
* is not a supertype of the runtime type of every element in
|
||||
* this list
|
||||
* @throws NullPointerException if the specified array is null
|
||||
*/
|
||||
public <T> T[] toArray(T[] a) {
|
||||
if (a.length < size)
|
||||
a = (T[])java.lang.reflect.Array.newInstance(
|
||||
a.getClass().getComponentType(), size);
|
||||
int i = 0;
|
||||
Object[] result = a;
|
||||
for (Entry<E> e = header.next; e != header; e = e.next)
|
||||
result[i++] = e.element;
|
||||
|
||||
if (a.length > size)
|
||||
a[size] = null;
|
||||
|
||||
return a;
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user