/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You 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 org.apache.commons.collections.primitives;

 import java.io.IOException;

 import java.io.ObjectInputStream;

 import java.io.ObjectOutputStream;

 import java.io.Serializable;

 /**

  * An {@link ShortList} backed by an array of <code>short</code>s.

  * This implementation supports all optional methods.

  * 

  * @since Commons Primitives 1.0

  * @version $Revision: 480460 $ $Date: 2006-11-29 03:14:21 -0500 (Wed, 29 Nov 2006) $

  * 

  * @author Rodney Waldhoff 

  */

 public class ArrayShortList extends RandomAccessShortList implements ShortList, Serializable {

     // constructors

     //-------------------------------------------------------------------------

     /** 

      * Construct an empty list with the default

      * initial capacity.

      */

     public ArrayShortList() {

         this(8);

     }    

     /**

      * Construct an empty list with the given

      * initial capacity.

      * @throws IllegalArgumentException when <i>initialCapacity</i> is negative

      */

     public ArrayShortList(int initialCapacity) {

         if(initialCapacity < 0) {

             throw new IllegalArgumentException("capacity " + initialCapacity);

         }

         _data = new short[initialCapacity];

         _size = 0;

     }    

     /** 

      * Constructs a list containing the elements of the given collection, 

      * in the order they are returned by that collection's iterator.

      * 

      * @see ArrayShortList#addAll(org.apache.commons.collections.primitives.ShortCollection)

      * @param that the non-<code>null</code> collection of <code>short</code>s 

      *        to add

      * @throws NullPointerException if <i>that</i> is <code>null</code>

      */

     public ArrayShortList(ShortCollection that) { 

         this(that.size());

         addAll(that);

     }    

     /**

      * Constructs a list by copying the specified array.

      * 

      * @param array  the array to initialize the collection with

      * @throws NullPointerException if the array is <code>null</code>

      */

     public ArrayShortList(short[] array) { 

         this(array.length);

         System.arraycopy(array, 0, _data, 0, array.length);

         _size = array.length;

     }

     // ShortList methods

     //-------------------------------------------------------------------------

     public short get(int index) {

         checkRange(index);

         return _data[index];

     }

     public int size() {

         return _size;

     }

     /** 

      * Removes the element at the specified position in 

      * (optional operation).  Any subsequent elements 

      * are shifted to the left, subtracting one from their 

      * indices.  Returns the element that was removed.

      * 

      * @param index the index of the element to remove

      * @return the value of the element that was removed

      * 

      * @throws UnsupportedOperationException when this operation is not 

      *         supported

      * @throws IndexOutOfBoundsException if the specified index is out of range

      */

     public short removeElementAt(int index) {

         checkRange(index);

         incrModCount();

         short oldval = _data[index];

         int numtomove = _size - index - 1;

         if(numtomove > 0) {

             System.arraycopy(_data,index+1,_data,index,numtomove);

         }

         _size--;

         return oldval;

     }

     /** 

      * Replaces the element at the specified 

      * position in me with the specified element

      * (optional operation). 

      * 

      * @param index the index of the element to change

      * @param element the value to be stored at the specified position

      * @return the value previously stored at the specified position

      * 

      * @throws UnsupportedOperationException when this operation is not 

      *         supported

      * @throws IndexOutOfBoundsException if the specified index is out of range

      */

     public short set(int index, short element) {

         checkRange(index);

         incrModCount();

         short oldval = _data[index];

         _data[index] = element;

         return oldval;

     }

     /** 

      * Inserts the specified element at the specified position 

      * (optional operation). Shifts the element currently 

      * at that position (if any) and any subsequent elements to the 

      * right, increasing their indices.

      * 

      * @param index the index at which to insert the element

      * @param element the value to insert

      * 

      * @throws UnsupportedOperationException when this operation is not 

      *         supported

      * @throws IllegalArgumentException if some aspect of the specified element 

      *         prevents it from being added to me

      * @throws IndexOutOfBoundsException if the specified index is out of range

      */

     public void add(int index, short element) {

         checkRangeIncludingEndpoint(index);

         incrModCount();

         ensureCapacity(_size+1);

         int numtomove = _size-index;

         System.arraycopy(_data,index,_data,index+1,numtomove);

         _data[index] = element;

         _size++;

     }

     public void clear() {

         incrModCount();

         _size = 0;

     }

     public boolean addAll(ShortCollection collection) {

         return addAll(size(), collection);

     }

     public boolean addAll(int index, ShortCollection collection) {

         if (collection.size() == 0) {

             return false;

         }

         checkRangeIncludingEndpoint(index);

         incrModCount();

         ensureCapacity(_size + collection.size());

         if (index != _size) {

             // Need to move some elements

             System.arraycopy(_data, index, _data, index + collection.size(), _size - index);

         }

         for (ShortIterator it = collection.iterator(); it.hasNext();) {

             _data[index] = it.next();

             index++;

         }

         _size += collection.size();

         return true;

     }

     // capacity methods

     //-------------------------------------------------------------------------

     /** 

      * Increases my capacity, if necessary, to ensure that I can hold at 

      * least the number of elements specified by the minimum capacity 

      * argument without growing.

      */

     public void ensureCapacity(int mincap) {

         incrModCount();

         if(mincap > _data.length) {

             int newcap = (_data.length * 3)/2 + 1;

             short[] olddata = _data;

             _data = new short[newcap < mincap ? mincap : newcap];

             System.arraycopy(olddata,0,_data,0,_size);

         }

     }

     /** 

      * Reduce my capacity, if necessary, to match my

      * current {@link #size size}.

      */

     public void trimToSize() {

         incrModCount();

         if(_size < _data.length) {

             short[] olddata = _data;

             _data = new short[_size];

             System.arraycopy(olddata,0,_data,0,_size);

         }

     }

     // private methods

     //-------------------------------------------------------------------------

     private void writeObject(ObjectOutputStream out) throws IOException{

         out.defaultWriteObject();

         out.writeInt(_data.length);

         for(int i=0;i<_size;i++) {

             out.writeShort(_data[i]);

         }

     }

     private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {

         in.defaultReadObject();

         _data = new short[in.readInt()];

         for(int i=0;i<_size;i++) {

             _data[i] = in.readShort();

         }

     }

     private final void checkRange(int index) {

         if(index < 0 || index >= _size) {

             throw new IndexOutOfBoundsException("Should be at least 0 and less than " + _size + ", found " + index);

         }

     }

     private final void checkRangeIncludingEndpoint(int index) {

         if(index < 0 || index > _size) {

             throw new IndexOutOfBoundsException("Should be at least 0 and at most " + _size + ", found " + index);

         }

     }

     // attributes

     //-------------------------------------------------------------------------

     private transient short[] _data = null;

     private int _size = 0;

 }