Proyectos de Subversion Moodle

<?php

/**

 * This file is part of FPDI

 *

 * @package   setasign\Fpdi

 * @copyright Copyright (c) 2024 Setasign GmbH & Co. KG (https://www.setasign.com)

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

 */

namespace setasign\Fpdi\PdfReader;

use setasign\Fpdi\FpdiException;

use setasign\Fpdi\GraphicsState;

use setasign\Fpdi\Math\Vector;

use setasign\Fpdi\PdfParser\Filter\FilterException;

use setasign\Fpdi\PdfParser\PdfParser;

use setasign\Fpdi\PdfParser\PdfParserException;

use setasign\Fpdi\PdfParser\Type\PdfArray;

use setasign\Fpdi\PdfParser\Type\PdfDictionary;

use setasign\Fpdi\PdfParser\Type\PdfHexString;

use setasign\Fpdi\PdfParser\Type\PdfIndirectObject;

use setasign\Fpdi\PdfParser\Type\PdfName;

use setasign\Fpdi\PdfParser\Type\PdfNull;

use setasign\Fpdi\PdfParser\Type\PdfNumeric;

use setasign\Fpdi\PdfParser\Type\PdfStream;

use setasign\Fpdi\PdfParser\Type\PdfString;

use setasign\Fpdi\PdfParser\Type\PdfType;

use setasign\Fpdi\PdfParser\Type\PdfTypeException;

use setasign\Fpdi\PdfReader\DataStructure\Rectangle;

use setasign\Fpdi\PdfParser\CrossReference\CrossReferenceException;

/**

 * Class representing a page of a PDF document

 */

class Page

{

    /**

     * @var PdfIndirectObject

     */

    protected $pageObject;

    /**

     * @var PdfDictionary

     */

    protected $pageDictionary;

    /**

     * @var PdfParser

     */

    protected $parser;

    /**

     * Inherited attributes

     *

     * @var null|array

     */

    protected $inheritedAttributes;

    /**

     * Page constructor.

     *

     * @param PdfIndirectObject $page

     * @param PdfParser $parser

     */

    public function __construct(PdfIndirectObject $page, PdfParser $parser)

    {

        $this->pageObject = $page;

        $this->parser = $parser;

    }

    /**

     * Get the indirect object of this page.

     *

     * @return PdfIndirectObject

     */

    public function getPageObject()

    {

        return $this->pageObject;

    }

    /**

     * Get the dictionary of this page.

     *

     * @return PdfDictionary

     * @throws PdfParserException

     * @throws PdfTypeException

     * @throws CrossReferenceException

     */

    public function getPageDictionary()

    {

        if ($this->pageDictionary === null) {

            $this->pageDictionary = PdfDictionary::ensure(PdfType::resolve($this->getPageObject(), $this->parser));

        }

        return $this->pageDictionary;

    }

    /**

     * Get a page attribute.

     *

     * @param string $name

     * @param bool $inherited

     * @return PdfType|null

     * @throws PdfParserException

     * @throws PdfTypeException

     * @throws CrossReferenceException

     */

    public function getAttribute($name, $inherited = true)

    {

        $dict = $this->getPageDictionary();

        if (isset($dict->value[$name])) {

            return $dict->value[$name];

        }

        $inheritedKeys = ['Resources', 'MediaBox', 'CropBox', 'Rotate'];

        if ($inherited && \in_array($name, $inheritedKeys, true)) {

            if ($this->inheritedAttributes === null) {

                $this->inheritedAttributes = [];

                $inheritedKeys = \array_filter($inheritedKeys, function ($key) use ($dict) {

                    return !isset($dict->value[$key]);

                });

                if (\count($inheritedKeys) > 0) {

                    $parentDict = PdfType::resolve(PdfDictionary::get($dict, 'Parent'), $this->parser);

                    while ($parentDict instanceof PdfDictionary) {

                        foreach ($inheritedKeys as $index => $key) {

                            if (isset($parentDict->value[$key])) {

                                $this->inheritedAttributes[$key] = $parentDict->value[$key];

                                unset($inheritedKeys[$index]);

                            }

                        }

                        /** @noinspection NotOptimalIfConditionsInspection */

                        if (isset($parentDict->value['Parent']) && \count($inheritedKeys) > 0) {

                            $parentDict = PdfType::resolve(PdfDictionary::get($parentDict, 'Parent'), $this->parser);

                        } else {

                            break;

                        }

                    }

                }

            }

            if (isset($this->inheritedAttributes[$name])) {

                return $this->inheritedAttributes[$name];

            }

        }

        return null;

    }

    /**

     * Get the rotation value.

     *

     * @return int

     * @throws PdfParserException

     * @throws PdfTypeException

     * @throws CrossReferenceException

     */

    public function getRotation()

    {

        $rotation = $this->getAttribute('Rotate');

        if ($rotation === null) {

            return 0;

        }

        $rotation = PdfNumeric::ensure(PdfType::resolve($rotation, $this->parser))->value % 360;

        if ($rotation < 0) {

            $rotation += 360;

        }

        return $rotation;

    }

    /**

     * Get a boundary of this page.

     *

     * @param string $box

     * @param bool $fallback

     * @return bool|Rectangle

     * @throws PdfParserException

     * @throws PdfTypeException

     * @throws CrossReferenceException

     * @see PageBoundaries

     */

    public function getBoundary($box = PageBoundaries::CROP_BOX, $fallback = true)

    {

        $value = $this->getAttribute($box);

        if ($value !== null) {

            return Rectangle::byPdfArray($value, $this->parser);

        }

        if ($fallback === false) {

            return false;

        }

        switch ($box) {

            case PageBoundaries::BLEED_BOX:

            case PageBoundaries::TRIM_BOX:

            case PageBoundaries::ART_BOX:

                return $this->getBoundary(PageBoundaries::CROP_BOX, true);

            case PageBoundaries::CROP_BOX:

                return $this->getBoundary(PageBoundaries::MEDIA_BOX, true);

        }

        return false;

    }

    /**

     * Get the width and height of this page.

     *

     * @param string $box

     * @param bool $fallback

     * @return array|bool

     * @throws PdfParserException

     * @throws PdfTypeException

     * @throws CrossReferenceException

     */

    public function getWidthAndHeight($box = PageBoundaries::CROP_BOX, $fallback = true)

    {

        $boundary = $this->getBoundary($box, $fallback);

        if ($boundary === false) {

            return false;

        }

        $rotation = $this->getRotation();

        $interchange = ($rotation / 90) % 2;

        return [

            $interchange ? $boundary->getHeight() : $boundary->getWidth(),

            $interchange ? $boundary->getWidth() : $boundary->getHeight()

        ];

    }

    /**

     * Get the raw content stream.

     *

     * @return string

     * @throws PdfReaderException

     * @throws PdfTypeException

     * @throws FilterException

     * @throws PdfParserException

     */

    public function getContentStream()

    {

        $dict = $this->getPageDictionary();

        $contents = PdfType::resolve(PdfDictionary::get($dict, 'Contents'), $this->parser);

        if ($contents instanceof PdfNull) {

            return '';

        }

        if ($contents instanceof PdfArray) {

            $result = [];

            foreach ($contents->value as $content) {

                $content = PdfType::resolve($content, $this->parser);

                if (!($content instanceof PdfStream)) {

                    continue;

                }

                $result[] = $content->getUnfilteredStream();

            }

            return \implode("\n", $result);

        }

        if ($contents instanceof PdfStream) {

            return $contents->getUnfilteredStream();

        }

        throw new PdfReaderException(

            'Array or stream expected.',

            PdfReaderException::UNEXPECTED_DATA_TYPE

        );

    }

    /**

     * Get information of all external links on this page.

     *

     * All coordinates are normalized in view to rotation and translation of the boundary-box, so that their

     * origin is lower-left.

     *

     * The URI is the binary value of the PDF string object. It can be in PdfDocEncoding or in UTF-16BE encoding.

     *

     * @return array

     */

    public function getExternalLinks($box = PageBoundaries::CROP_BOX)

    {

        try {

            $dict = $this->getPageDictionary();

            $annotations = PdfType::resolve(PdfDictionary::get($dict, 'Annots'), $this->parser);

        } catch (FpdiException $e) {

            return [];

        }

        if (!$annotations instanceof PdfArray) {

            return [];

        }

        $links = [];

        foreach ($annotations->value as $entry) {

            try {

                $annotation = PdfType::resolve($entry, $this->parser);

                $value = PdfType::resolve(PdfDictionary::get($annotation, 'Subtype'), $this->parser);

                if (!$value instanceof PdfName || $value->value !== 'Link') {

                    continue;

                }

                $dest = PdfType::resolve(PdfDictionary::get($annotation, 'Dest'), $this->parser);

                if (!$dest instanceof PdfNull) {

                    continue;

                }

                $action = PdfType::resolve(PdfDictionary::get($annotation, 'A'), $this->parser);

                if (!$action instanceof PdfDictionary) {

                    continue;

                }

                $actionType = PdfType::resolve(PdfDictionary::get($action, 'S'), $this->parser);

                if (!$actionType instanceof PdfName || $actionType->value !== 'URI') {

                    continue;

                }

                $uri = PdfType::resolve(PdfDictionary::get($action, 'URI'), $this->parser);

                if ($uri instanceof PdfString) {

                    $uriValue = PdfString::unescape($uri->value);

                } elseif ($uri instanceof PdfHexString) {

                    $uriValue = \hex2bin($uri->value);

                } else {

                    continue;

                }

                $rect = PdfType::resolve(PdfDictionary::get($annotation, 'Rect'), $this->parser);

                if (!$rect instanceof PdfArray || count($rect->value) !== 4) {

                    continue;

                }

                $rect = Rectangle::byPdfArray($rect, $this->parser);

                if ($rect->getWidth() === 0 || $rect->getHeight() === 0) {

                    continue;

                }

                $bbox = $this->getBoundary($box);

                $rotation = $this->getRotation();

                $gs = new GraphicsState();

                $gs->translate(-$bbox->getLlx(), -$bbox->getLly());

                $gs->rotate($bbox->getLlx(), $bbox->getLly(), -$rotation);

                switch ($rotation) {

                    case 90:

                        $gs->translate(-$bbox->getWidth(), 0);

                        break;

                    case 180:

                        $gs->translate(-$bbox->getWidth(), -$bbox->getHeight());

                        break;

                    case 270:

                        $gs->translate(0, -$bbox->getHeight());

                        break;

                }

                $normalizedRect = Rectangle::byVectors(

                    $gs->toUserSpace(new Vector($rect->getLlx(), $rect->getLly())),

                    $gs->toUserSpace(new Vector($rect->getUrx(), $rect->getUry()))

                );

                $quadPoints = PdfType::resolve(PdfDictionary::get($annotation, 'QuadPoints'), $this->parser);

                $normalizedQuadPoints = [];

                if ($quadPoints instanceof PdfArray) {

                    $quadPointsCount = count($quadPoints->value);

                    if ($quadPointsCount % 8 === 0) {

                        for ($i = 0; ($i + 1) < $quadPointsCount; $i += 2) {

                            $x = PdfNumeric::ensure(PdfType::resolve($quadPoints->value[$i], $this->parser));

                            $y = PdfNumeric::ensure(PdfType::resolve($quadPoints->value[$i + 1], $this->parser));

                            $v = $gs->toUserSpace(new Vector($x->value, $y->value));

                            $normalizedQuadPoints[] = $v->getX();

                            $normalizedQuadPoints[] = $v->getY();

                        }

                    }

                }

                // we remove unsupported/unneeded values here

                unset(

                    $annotation->value['P'],

                    $annotation->value['NM'],

                    $annotation->value['AP'],

                    $annotation->value['AS'],

                    $annotation->value['Type'],

                    $annotation->value['Subtype'],

                    $annotation->value['Rect'],

                    $annotation->value['A'],

                    $annotation->value['QuadPoints'],

                    $annotation->value['Rotate'],

                    $annotation->value['M'],

                    $annotation->value['StructParent'],

                    $annotation->value['OC']

                );

                // ...and flatten the PDF object to eliminate any indirect references.

                // Indirect references are a problem when writing the output in FPDF

                // because FPDF uses pre-calculated object numbers while FPDI creates

                // them at runtime.

                $annotation = PdfType::flatten($annotation, $this->parser);

                $links[] = [

                    'rect' => $normalizedRect,

                    'quadPoints' => $normalizedQuadPoints,

                    'uri' => $uriValue,

                    'pdfObject' => $annotation

                ];

            } catch (FpdiException $e) {

                continue;

            }

        }

        return $links;

    }

}