<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Paginator

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: SerializableLimitIterator.php 23189 2010-10-20 18:55:32Z mabe $

 */

/**

 * @category   Zend

 * @package    Zend_Paginator

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Paginator_SerializableLimitIterator extends LimitIterator implements Serializable, ArrayAccess

{

    /**

     * Offset to first element

     *

     * @var int

     */

    private $_offset;

    /**

     * Maximum number of elements to show or -1 for all

     *

     * @var int

     */

    private $_count;

    /**

     * Construct a Zend_Paginator_SerializableLimitIterator

     *

     * @param Iterator $it Iterator to limit (must be serializable by un-/serialize)

     * @param int $offset Offset to first element

     * @param int $count Maximum number of elements to show or -1 for all

     * @see LimitIterator::__construct

     */

    public function __construct (Iterator $it, $offset=0, $count=-1)

    {

        parent::__construct($it, $offset, $count);

        $this->_offset = $offset;

        $this->_count = $count;

    }

    /**

     * @return string representation of the instance

     */

    public function serialize()

    {

        return serialize(array(

            'it'     => $this->getInnerIterator(),

            'offset' => $this->_offset,

            'count'  => $this->_count,

            'pos'    => $this->getPosition(),

        ));

    }

    /**

     * @param string $data representation of the instance

     */

    public function unserialize($data)

    {

        $dataArr = unserialize($data);

        $this->__construct($dataArr['it'], $dataArr['offset'], $dataArr['count']);

        $this->seek($dataArr['pos']+$dataArr['offset']);

    }

    /**

     * Returns value of the Iterator

     *

     * @param int $offset

     * @return mixed

     */

    public function offsetGet($offset)

    {

        $currentOffset = $this->key();

        $this->seek($offset);

        $current = $this->current();

        $this->seek($currentOffset);

        return $current;

    }

    /**

     * Does nothing

     * Required by the ArrayAccess implementation

     *

     * @param int $offset

     * @param mixed $value

     */

    public function offsetSet($offset, $value)

    {

    }

    /**

     * Determine if a value of Iterator is set and is not NULL

     *

     * @param int $offset

     */

    public function offsetExists($offset)

    {

        if ($offset > 0 && $offset < $this->_count) {

            try {

                $currentOffset = $this->key();

                $this->seek($offset);

                $current = $this->current();

                $this->seek($currentOffset);

                return null !== $current;

            } catch (OutOfBoundsException $e) {

                // reset position in case of exception is assigned null

                $this->rewind();

                $this->seek($currentOffset);

                return false;

            }

        }

        return false;

    }

    /**

     * Does nothing

     * Required by the ArrayAccess implementation

     *

     * @param int $offset

     */

    public function offsetUnset($offset)

    {

    }

}