/mod/assign/feedback/editpdf/fpdi/fpdi_pdf_parser.php

<?php

/**

 * This file is part of FPDI

 *

 * @package   FPDI

 * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)

 * @license   http://opensource.org/licenses/mit-license The MIT License

 * @version   1.6.1

 */



if (!class_exists('pdf_parser')) {

    require_once('pdf_parser.php');

}



/**

 * Class fpdi_pdf_parser

 */

class fpdi_pdf_parser extends pdf_parser

{

    /**

     * Pages

     *

     * Index begins at 0

     *

     * @var array

     */

    protected $_pages;

    

    /**

     * Page count

     *

     * @var integer

     */

    protected $_pageCount;

    

    /**

     * Current page number

     *

     * @var integer

     */

    public $pageNo;

    

    /**

     * PDF version of imported document

     *

     * @var string

     */

    public $_pdfVersion;

    

    /**

     * Available BoxTypes

     *

     * @var array

     */

    public $availableBoxes = array('/MediaBox', '/CropBox', '/BleedBox', '/TrimBox', '/ArtBox');

        

    /**

     * The constructor.

     *

     * @param string $filename The source filename

     */

    public function __construct($filename)

    {

        parent::__construct($filename);



        // resolve Pages-Dictonary

        $pages = $this->resolveObject($this->_root[1][1]['/Pages']);



        // Read pages

        $this->_readPages($pages, $this->_pages);

        

        // count pages;

        $this->_pageCount = count($this->_pages);

    }

    

    /**

     * Get page count from source file.

     *

     * @return int

     */

    public function getPageCount()

    {

        return $this->_pageCount;

    }



    /**

     * Set the page number.

     *

     * @param int $pageNo Page number to use

     * @throws InvalidArgumentException

     */

    public function setPageNo($pageNo)

    {

        $pageNo = ((int) $pageNo) - 1;



        if ($pageNo < 0 || $pageNo >= $this->getPageCount()) {

            throw new InvalidArgumentException('Invalid page number!');

        }



        $this->pageNo = $pageNo;

    }

    

    /**

     * Get page-resources from current page

     *

     * @return array|boolean

     */

    public function getPageResources()

    {

        return $this->_getPageResources($this->_pages[$this->pageNo]);

    }

    

    /**

     * Get page-resources from a /Page dictionary.

     *

     * @param array $obj Array of pdf-data

     * @return array|boolean

     */

    protected function _getPageResources($obj)

    {

        $obj = $this->resolveObject($obj);



        // If the current object has a resources

        // dictionary associated with it, we use

        // it. Otherwise, we move back to its

        // parent object.

        if (isset($obj[1][1]['/Resources'])) {

            $res = $this->resolveObject($obj[1][1]['/Resources']);

            if ($res[0] == pdf_parser::TYPE_OBJECT)

                return $res[1];

            return $res;

        }



        if (!isset($obj[1][1]['/Parent'])) {

            return false;

        }



        $res = $this->_getPageResources($obj[1][1]['/Parent']);

        if ($res[0] == pdf_parser::TYPE_OBJECT)

            return $res[1];

        return $res;

    }



    /**

     * Get content of current page.

     *

     * If /Contents is an array, the streams are concatenated

     *

     * @return string

     */

    public function getContent()

    {

        $buffer = '';

        

        if (isset($this->_pages[$this->pageNo][1][1]['/Contents'])) {

            $contents = $this->_getPageContent($this->_pages[$this->pageNo][1][1]['/Contents']);

            foreach ($contents AS $tmpContent) {

                $buffer .= $this->_unFilterStream($tmpContent) . ' ';

            }

        }

        

        return $buffer;

    }



    /**

     * Resolve all content objects.

     *

     * @param array $contentRef

     * @return array

     */

    protected function _getPageContent($contentRef)

    {

        $contents = array();

        

        if ($contentRef[0] == pdf_parser::TYPE_OBJREF) {

            $content = $this->resolveObject($contentRef);

            if ($content[1][0] == pdf_parser::TYPE_ARRAY) {

                $contents = $this->_getPageContent($content[1]);

            } else {

                $contents[] = $content;

            }

        } else if ($contentRef[0] == pdf_parser::TYPE_ARRAY) {

            foreach ($contentRef[1] AS $tmp_content_ref) {

                $contents = array_merge($contents, $this->_getPageContent($tmp_content_ref));

            }

        }



        return $contents;

    }



    /**

     * Get a boundary box from a page

     *

     * Array format is same as used by FPDF_TPL.

     *

     * @param array $page a /Page dictionary

     * @param string $boxIndex Type of box {see {@link $availableBoxes})

     * @param float Scale factor from user space units to points

     *

     * @return array|boolean

     */

    protected function _getPageBox($page, $boxIndex, $k)

    {

        $page = $this->resolveObject($page);

        $box = null;

        if (isset($page[1][1][$boxIndex])) {

            $box = $page[1][1][$boxIndex];

        }

        

        if (!is_null($box) && $box[0] == pdf_parser::TYPE_OBJREF) {

            $tmp_box = $this->resolveObject($box);

            $box = $tmp_box[1];

        }

            

        if (!is_null($box) && $box[0] == pdf_parser::TYPE_ARRAY) {

            $b = $box[1];

            return array(

                'x' => $b[0][1] / $k,

                'y' => $b[1][1] / $k,

                'w' => abs($b[0][1] - $b[2][1]) / $k,

                'h' => abs($b[1][1] - $b[3][1]) / $k,

                'llx' => min($b[0][1], $b[2][1]) / $k,

                'lly' => min($b[1][1], $b[3][1]) / $k,

                'urx' => max($b[0][1], $b[2][1]) / $k,

                'ury' => max($b[1][1], $b[3][1]) / $k,

            );

        } else if (!isset($page[1][1]['/Parent'])) {

            return false;

        } else {

            return $this->_getPageBox($this->resolveObject($page[1][1]['/Parent']), $boxIndex, $k);

        }

    }



    /**

     * Get all page boundary boxes by page number

     * 

     * @param int $pageNo The page number

     * @param float $k Scale factor from user space units to points

     * @return array

     * @throws InvalidArgumentException

     */

    public function getPageBoxes($pageNo, $k)

    {

        if (!isset($this->_pages[$pageNo - 1])) {

            throw new InvalidArgumentException('Page ' . $pageNo . ' does not exists.');

        }



        return $this->_getPageBoxes($this->_pages[$pageNo - 1], $k);

    }

    

    /**

     * Get all boxes from /Page dictionary

     *

     * @param array $page A /Page dictionary

     * @param float $k Scale factor from user space units to points

     * @return array

     */

    protected function _getPageBoxes($page, $k)

    {

        $boxes = array();



        foreach($this->availableBoxes AS $box) {

            if ($_box = $this->_getPageBox($page, $box, $k)) {

                $boxes[$box] = $_box;

            }

        }



        return $boxes;

    }



    /**

     * Get the page rotation by page number

     *

     * @param integer $pageNo

     * @throws InvalidArgumentException

     * @return array

     */

    public function getPageRotation($pageNo)

    {

        if (!isset($this->_pages[$pageNo - 1])) {

            throw new InvalidArgumentException('Page ' . $pageNo . ' does not exists.');

        }



        return $this->_getPageRotation($this->_pages[$pageNo - 1]);

    }



    /**

     * Get the rotation value of a page

     *

     * @param array $obj A /Page dictionary

     * @return array|bool

     */

    protected function _getPageRotation($obj)

    {

        $obj = $this->resolveObject($obj);

        if (isset($obj[1][1]['/Rotate'])) {

            $res = $this->resolveObject($obj[1][1]['/Rotate']);

            if ($res[0] == pdf_parser::TYPE_OBJECT)

                return $res[1];

            return $res;

        }



        if (!isset($obj[1][1]['/Parent'])) {

            return false;

        }



        $res = $this->_getPageRotation($obj[1][1]['/Parent']);

        if ($res[0] == pdf_parser::TYPE_OBJECT)

            return $res[1];



        return $res;

    }



    /**

     * Read all pages

     *

     * @param array $pages /Pages dictionary

     * @param array $result The result array

     * @throws Exception

     */

    protected function _readPages(&$pages, &$result)

    {

        // Get the kids dictionary

        $_kids = $this->resolveObject($pages[1][1]['/Kids']);



        if (!is_array($_kids)) {

            throw new Exception('Cannot find /Kids in current /Page-Dictionary');

        }



        if ($_kids[0] === self::TYPE_OBJECT) {

            $_kids =  $_kids[1];

        }



        $kids = $_kids[1];



        foreach ($kids as $v) {

            $pg = $this->resolveObject($v);

            if ($pg[1][1]['/Type'][1] === '/Pages') {

                // If one of the kids is an embedded

                // /Pages array, resolve it as well.

                $this->_readPages($pg, $result);

            } else {

                $result[] = $pg;

            }

        }

    }

}