<?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_Pdf

 * @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: Table.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * PDF file reference table

 *

 * @category   Zend

 * @package    Zend_Pdf

 * @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_Pdf_Element_Reference_Table

{

    /**

     * Parent reference table

     *

     * @var Zend_Pdf_Element_Reference_Table

     */

    private $_parent;

    /**

     * Free entries

     * 'reference' => next free object number

     *

     * @var array

     */

    private $_free;

    /**

     * Generation numbers for free objects.

     * Array: objNum => nextGeneration

     *

     * @var array

     */

    private $_generations;

    /**

     * In use entries

     * 'reference' => offset

     *

     * @var array

     */

    private $_inuse;

    /**

     * Generation numbers for free objects.

     * Array: objNum => objGeneration

     *

     * @var array

     */

    private $_usedObjects;

    /**

     * Object constructor

     */

    public function  __construct()

    {

        $this->_parent = null;

        $this->_free   = array();  $this->_generations = array();

        $this->_inuse  = array();  $this->_usedObjects = array();

    }

    /**

     * Add reference to the reference table

     *

     * @param string $ref

     * @param integer $offset

     * @param boolean $inuse

     */

    public function addReference($ref, $offset, $inuse = true)

    {

        $refElements = explode(' ', $ref);

        if (!is_numeric($refElements[0]) || !is_numeric($refElements[1]) || $refElements[2] != 'R') {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception("Incorrect reference: '$ref'");

        }

        $objNum = (int)$refElements[0];

        $genNum = (int)$refElements[1];

        if ($inuse) {

            $this->_inuse[$ref]          = $offset;

            $this->_usedObjects[$objNum] = $objNum;

        } else {

            $this->_free[$ref]           = $offset;

            $this->_generations[$objNum] = $genNum;

        }

    }

    /**

     * Set parent reference table

     *

     * @param Zend_Pdf_Element_Reference_Table $parent

     */

    public function setParent(self $parent)

    {

        $this->_parent = $parent;

    }

    /**

     * Get object offset

     *

     * @param string $ref

     * @return integer

     */

    public function getOffset($ref)

    {

        if (isset($this->_inuse[$ref])) {

            return $this->_inuse[$ref];

        }

        if (isset($this->_free[$ref])) {

            return null;

        }

        if (isset($this->_parent)) {

            return $this->_parent->getOffset($ref);

        }

        return null;

    }

    /**

     * Get next object from a list of free objects.

     *

     * @param string $ref

     * @return integer

     * @throws Zend_Pdf_Exception

     */

    public function getNextFree($ref)

    {

        if (isset($this->_inuse[$ref])) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception('Object is not free');

        }

        if (isset($this->_free[$ref])) {

            return $this->_free[$ref];

        }

        if (isset($this->_parent)) {

            return $this->_parent->getNextFree($ref);

        }

        require_once 'Zend/Pdf/Exception.php';

        throw new Zend_Pdf_Exception('Object not found.');

    }

    /**

     * Get next generation number for free object

     *

     * @param integer $objNum

     * @return unknown

     */

    public function getNewGeneration($objNum)

    {

        if (isset($this->_usedObjects[$objNum])) {

            require_once 'Zend/Pdf/Exception.php';

            throw new Zend_Pdf_Exception('Object is not free');

        }

        if (isset($this->_generations[$objNum])) {

            return $this->_generations[$objNum];

        }

        if (isset($this->_parent)) {

            return $this->_parent->getNewGeneration($objNum);

        }

        require_once 'Zend/Pdf/Exception.php';

        throw new Zend_Pdf_Exception('Object not found.');

    }

}