File: /home/iestorre/moodleAW/moodle05/mod/assign/feedback/editpdf/classes/pdf.php
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Library code for manipulating PDFs
*
* @package assignfeedback_editpdf
* @copyright 2012 Davo Smith
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace assignfeedback_editpdf;
defined('MOODLE_INTERNAL') || die();
global $CFG;
require_once($CFG->libdir.'/pdflib.php');
require_once($CFG->dirroot.'/mod/assign/feedback/editpdf/fpdi/fpdi.php');
/**
* Library code for manipulating PDFs
*
* @package assignfeedback_editpdf
* @copyright 2012 Davo Smith
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class pdf extends \FPDI {
/** @var int the number of the current page in the PDF being processed */
protected $currentpage = 0;
/** @var int the total number of pages in the PDF being processed */
protected $pagecount = 0;
/** @var float used to scale the pixel position of annotations (in the database) to the position in the final PDF */
protected $scale = 0.0;
/** @var string the path in which to store generated page images */
protected $imagefolder = null;
/** @var string the path to the PDF currently being processed */
protected $filename = null;
/** No errors */
const GSPATH_OK = 'ok';
/** Not set */
const GSPATH_EMPTY = 'empty';
/** Does not exist */
const GSPATH_DOESNOTEXIST = 'doesnotexist';
/** Is a dir */
const GSPATH_ISDIR = 'isdir';
/** Not executable */
const GSPATH_NOTEXECUTABLE = 'notexecutable';
/** Test file missing */
const GSPATH_NOTESTFILE = 'notestfile';
/** Any other error */
const GSPATH_ERROR = 'error';
/** Min. width an annotation should have */
const MIN_ANNOTATION_WIDTH = 5;
/** Min. height an annotation should have */
const MIN_ANNOTATION_HEIGHT = 5;
/**
* Combine the given PDF files into a single PDF. Optionally add a coversheet and coversheet fields.
* @param string[] $pdflist the filenames of the files to combine
* @param string $outfilename the filename to write to
* @return int the number of pages in the combined PDF
*/
public function combine_pdfs($pdflist, $outfilename) {
raise_memory_limit(MEMORY_EXTRA);
$olddebug = error_reporting(0);
$this->setPageUnit('pt');
$this->setPrintHeader(false);
$this->setPrintFooter(false);
$this->scale = 72.0 / 100.0;
$this->SetFont('helvetica', '', 16.0 * $this->scale);
$this->SetTextColor(0, 0, 0);
$totalpagecount = 0;
foreach ($pdflist as $file) {
$pagecount = $this->setSourceFile($file);
$totalpagecount += $pagecount;
for ($i = 1; $i<=$pagecount; $i++) {
$this->create_page_from_source($i);
}
}
$this->save_pdf($outfilename);
error_reporting($olddebug);
return $totalpagecount;
}
/**
* The number of the current page in the PDF being processed
* @return int
*/
public function current_page() {
return $this->currentpage;
}
/**
* The total number of pages in the PDF being processed
* @return int
*/
public function page_count() {
return $this->pagecount;
}
/**
* Load the specified PDF and set the initial output configuration
* Used when processing comments and outputting a new PDF
* @param string $filename the path to the PDF to load
* @return int the number of pages in the PDF
*/
public function load_pdf($filename) {
raise_memory_limit(MEMORY_EXTRA);
$olddebug = error_reporting(0);
$this->setPageUnit('pt');
$this->scale = 72.0 / 100.0;
$this->SetFont('helvetica', '', 16.0 * $this->scale);
$this->SetFillColor(255, 255, 176);
$this->SetDrawColor(0, 0, 0);
$this->SetLineWidth(1.0 * $this->scale);
$this->SetTextColor(0, 0, 0);
$this->setPrintHeader(false);
$this->setPrintFooter(false);
$this->pagecount = $this->setSourceFile($filename);
$this->filename = $filename;
error_reporting($olddebug);
return $this->pagecount;
}
/**
* Sets the name of the PDF to process, but only loads the file if the
* pagecount is zero (in order to count the number of pages)
* Used when generating page images (but not a new PDF)
* @param string $filename the path to the PDF to process
* @param int $pagecount optional the number of pages in the PDF, if known
* @return int the number of pages in the PDF
*/
public function set_pdf($filename, $pagecount = 0) {
if ($pagecount == 0) {
return $this->load_pdf($filename);
} else {
$this->filename = $filename;
$this->pagecount = $pagecount;
return $pagecount;
}
}
/**
* Copy the next page from the source file and set it as the current page
* @return bool true if successful
*/
public function copy_page() {
if (!$this->filename) {
return false;
}
if ($this->currentpage>=$this->pagecount) {
return false;
}
$this->currentpage++;
$this->create_page_from_source($this->currentpage);
return true;
}
/**
* Create a page from a source PDF.
*
* @param int $pageno
*/
protected function create_page_from_source($pageno) {
// Get the size (and deduce the orientation) of the next page.
$template = $this->importPage($pageno);
$size = $this->getTemplateSize($template);
$orientation = 'P';
if ($size['w'] > $size['h']) {
$orientation = 'L';
}
// Create a page of the required size / orientation.
$this->AddPage($orientation, array($size['w'], $size['h']));
// Prevent new page creation when comments are at the bottom of a page.
$this->setPageOrientation($orientation, false, 0);
// Fill in the page with the original contents from the student.
$this->useTemplate($template);
}
/**
* Copy all the remaining pages in the file
*/
public function copy_remaining_pages() {
$morepages = true;
while ($morepages) {
$morepages = $this->copy_page();
}
}
/**
* Add a comment to the current page
* @param string $text the text of the comment
* @param int $x the x-coordinate of the comment (in pixels)
* @param int $y the y-coordinate of the comment (in pixels)
* @param int $width the width of the comment (in pixels)
* @param string $colour optional the background colour of the comment (red, yellow, green, blue, white, clear)
* @return bool true if successful (always)
*/
public function add_comment($text, $x, $y, $width, $colour = 'yellow') {
if (!$this->filename) {
return false;
}
$this->SetDrawColor(51, 51, 51);
switch ($colour) {
case 'red':
$this->SetFillColor(249, 181, 179);
break;
case 'green':
$this->SetFillColor(214, 234, 178);
break;
case 'blue':
$this->SetFillColor(203, 217, 237);
break;
case 'white':
$this->SetFillColor(255, 255, 255);
break;
default: /* Yellow */
$this->SetFillColor(255, 236, 174);
break;
}
$x *= $this->scale;
$y *= $this->scale;
$width *= $this->scale;
$text = str_replace('<', '<', $text);
$text = str_replace('>', '>', $text);
// Draw the text with a border, but no background colour (using a background colour would cause the fill to
// appear behind any existing content on the page, hence the extra filled rectangle drawn below).
$this->MultiCell($width, 1.0, $text, 0, 'L', 0, 4, $x, $y); /* width, height, text, border, justify, fill, ln, x, y */
if ($colour != 'clear') {
$newy = $this->GetY();
// Now we know the final size of the comment, draw a rectangle with the background colour.
$this->Rect($x, $y, $width, $newy - $y, 'DF');
// Re-draw the text over the top of the background rectangle.
$this->MultiCell($width, 1.0, $text, 0, 'L', 0, 4, $x, $y); /* width, height, text, border, justify, fill, ln, x, y */
}
return true;
}
/**
* Add an annotation to the current page
* @param int $sx starting x-coordinate (in pixels)
* @param int $sy starting y-coordinate (in pixels)
* @param int $ex ending x-coordinate (in pixels)
* @param int $ey ending y-coordinate (in pixels)
* @param string $colour optional the colour of the annotation (red, yellow, green, blue, white, black)
* @param string $type optional the type of annotation (line, oval, rectangle, highlight, pen, stamp)
* @param int[]|string $path optional for 'pen' annotations this is an array of x and y coordinates for
* the line, for 'stamp' annotations it is the name of the stamp file (without the path)
* @param string $imagefolder - Folder containing stamp images.
* @return bool true if successful (always)
*/
public function add_annotation($sx, $sy, $ex, $ey, $colour = 'yellow', $type = 'line', $path, $imagefolder) {
global $CFG;
if (!$this->filename) {
return false;
}
switch ($colour) {
case 'yellow':
$colourarray = array(255, 207, 53);
break;
case 'green':
$colourarray = array(153, 202, 62);
break;
case 'blue':
$colourarray = array(125, 159, 211);
break;
case 'white':
$colourarray = array(255, 255, 255);
break;
case 'black':
$colourarray = array(51, 51, 51);
break;
default: /* Red */
$colour = 'red';
$colourarray = array(239, 69, 64);
break;
}
$this->SetDrawColorArray($colourarray);
$sx *= $this->scale;
$sy *= $this->scale;
$ex *= $this->scale;
$ey *= $this->scale;
$this->SetLineWidth(3.0 * $this->scale);
switch ($type) {
case 'oval':
$rx = abs($sx - $ex) / 2;
$ry = abs($sy - $ey) / 2;
$sx = min($sx, $ex) + $rx;
$sy = min($sy, $ey) + $ry;
// $rx and $ry should be >= min width and height
if ($rx < self::MIN_ANNOTATION_WIDTH) {
$rx = self::MIN_ANNOTATION_WIDTH;
}
if ($ry < self::MIN_ANNOTATION_HEIGHT) {
$ry = self::MIN_ANNOTATION_HEIGHT;
}
$this->Ellipse($sx, $sy, $rx, $ry);
break;
case 'rectangle':
$w = abs($sx - $ex);
$h = abs($sy - $ey);
$sx = min($sx, $ex);
$sy = min($sy, $ey);
// Width or height should be >= min width and height
if ($w < self::MIN_ANNOTATION_WIDTH) {
$w = self::MIN_ANNOTATION_WIDTH;
}
if ($h < self::MIN_ANNOTATION_HEIGHT) {
$h = self::MIN_ANNOTATION_HEIGHT;
}
$this->Rect($sx, $sy, $w, $h);
break;
case 'highlight':
$w = abs($sx - $ex);
$h = 8.0 * $this->scale;
$sx = min($sx, $ex);
$sy = min($sy, $ey) + ($h * 0.5);
$this->SetAlpha(0.5, 'Normal', 0.5, 'Normal');
$this->SetLineWidth(8.0 * $this->scale);
// width should be >= min width
if ($w < self::MIN_ANNOTATION_WIDTH) {
$w = self::MIN_ANNOTATION_WIDTH;
}
$this->Rect($sx, $sy, $w, $h);
$this->SetAlpha(1.0, 'Normal', 1.0, 'Normal');
break;
case 'pen':
if ($path) {
$scalepath = array();
$points = preg_split('/[,:]/', $path);
foreach ($points as $point) {
$scalepath[] = intval($point) * $this->scale;
}
if (!empty($scalepath)) {
$this->PolyLine($scalepath, 'S');
}
}
break;
case 'stamp':
$imgfile = $imagefolder . '/' . clean_filename($path);
$w = abs($sx - $ex);
$h = abs($sy - $ey);
$sx = min($sx, $ex);
$sy = min($sy, $ey);
// Stamp is always more than 40px, so no need to check width/height.
$this->Image($imgfile, $sx, $sy, $w, $h);
break;
default: // Line.
$this->Line($sx, $sy, $ex, $ey);
break;
}
$this->SetDrawColor(0, 0, 0);
$this->SetLineWidth(1.0 * $this->scale);
return true;
}
/**
* Save the completed PDF to the given file
* @param string $filename the filename for the PDF (including the full path)
*/
public function save_pdf($filename) {
$olddebug = error_reporting(0);
$this->Output($filename, 'F');
error_reporting($olddebug);
}
/**
* Set the path to the folder in which to generate page image files
* @param string $folder
*/
public function set_image_folder($folder) {
$this->imagefolder = $folder;
}
/**
* Generate an image of the specified page in the PDF
* @param int $pageno the page to generate the image of
* @throws moodle_exception
* @throws coding_exception
* @return string the filename of the generated image
*/
public function get_image($pageno) {
if (!$this->filename) {
throw new \coding_exception('Attempting to generate a page image without first setting the PDF filename');
}
if (!$this->imagefolder) {
throw new \coding_exception('Attempting to generate a page image without first specifying the image output folder');
}
if (!is_dir($this->imagefolder)) {
throw new \coding_exception('The specified image output folder is not a valid folder');
}
$imagefile = $this->imagefolder.'/image_page' . $pageno . '.png';
$generate = true;
if (file_exists($imagefile)) {
if (filemtime($imagefile)>filemtime($this->filename)) {
// Make sure the image is newer than the PDF file.
$generate = false;
}
}
if ($generate) {
// Use ghostscript to generate an image of the specified page.
$gsexec = \escapeshellarg(\get_config('assignfeedback_editpdf', 'gspath'));
$imageres = \escapeshellarg(100);
$imagefilearg = \escapeshellarg($imagefile);
$filename = \escapeshellarg($this->filename);
$pagenoinc = \escapeshellarg($pageno + 1);
$command = "$gsexec -q -sDEVICE=png16m -dSAFER -dBATCH -dNOPAUSE -r$imageres -dFirstPage=$pagenoinc -dLastPage=$pagenoinc ".
"-dGraphicsAlphaBits=4 -dTextAlphaBits=4 -sOutputFile=$imagefilearg $filename";
$output = null;
$result = exec($command, $output);
if (!file_exists($imagefile)) {
$fullerror = '<pre>'.get_string('command', 'assignfeedback_editpdf')."\n";
$fullerror .= $command . "\n\n";
$fullerror .= get_string('result', 'assignfeedback_editpdf')."\n";
$fullerror .= htmlspecialchars($result) . "\n\n";
$fullerror .= get_string('output', 'assignfeedback_editpdf')."\n";
$fullerror .= htmlspecialchars(implode("\n",$output)) . '</pre>';
throw new \moodle_exception('errorgenerateimage', 'assignfeedback_editpdf', '', $fullerror);
}
}
return 'image_page'.$pageno.'.png';
}
/**
* Check to see if PDF is version 1.4 (or below); if not: use ghostscript to convert it
* @param stored_file $file
* @return string path to copy or converted pdf (false == fail)
*/
public static function ensure_pdf_compatible(\stored_file $file) {
$temparea = \make_temp_directory('assignfeedback_editpdf');
$hash = $file->get_contenthash(); // Use the contenthash to make sure the temp files have unique names.
$tempsrc = $temparea . "/src-$hash.pdf";
$tempdst = $temparea . "/dst-$hash.pdf";
$file->copy_content_to($tempsrc); // Copy the file.
$pdf = new pdf();
$pagecount = 0;
try {
$pagecount = $pdf->load_pdf($tempsrc);
} catch (\Exception $e) {
// PDF was not valid - try running it through ghostscript to clean it up.
$pagecount = 0;
}
if ($pagecount > 0) {
// Page is valid and can be read by tcpdf.
return $tempsrc;
}
$gsexec = \escapeshellarg(\get_config('assignfeedback_editpdf', 'gspath'));
$tempdstarg = \escapeshellarg($tempdst);
$tempsrcarg = \escapeshellarg($tempsrc);
$command = "$gsexec -q -sDEVICE=pdfwrite -dBATCH -dNOPAUSE -sOutputFile=$tempdstarg $tempsrcarg";
exec($command);
@unlink($tempsrc);
if (!file_exists($tempdst)) {
// Something has gone wrong in the conversion.
return false;
}
$pdf = new pdf();
$pagecount = 0;
try {
$pagecount = $pdf->load_pdf($tempdst);
} catch (\Exception $e) {
// PDF was not valid - try running it through ghostscript to clean it up.
$pagecount = 0;
}
if ($pagecount <= 0) {
@unlink($tempdst);
// Could not parse the converted pdf.
return false;
}
return $tempdst;
}
/**
* Test that the configured path to ghostscript is correct and working.
* @param bool $generateimage - If true - a test image will be generated to verify the install.
* @return bool
*/
public static function test_gs_path($generateimage = true) {
global $CFG;
$ret = (object)array(
'status' => self::GSPATH_OK,
'message' => null,
);
$gspath = \get_config('assignfeedback_editpdf', 'gspath');
if (empty($gspath)) {
$ret->status = self::GSPATH_EMPTY;
return $ret;
}
if (!file_exists($gspath)) {
$ret->status = self::GSPATH_DOESNOTEXIST;
return $ret;
}
if (is_dir($gspath)) {
$ret->status = self::GSPATH_ISDIR;
return $ret;
}
if (!is_executable($gspath)) {
$ret->status = self::GSPATH_NOTEXECUTABLE;
return $ret;
}
if (!$generateimage) {
return $ret;
}
$testfile = $CFG->dirroot.'/mod/assign/feedback/editpdf/tests/fixtures/testgs.pdf';
if (!file_exists($testfile)) {
$ret->status = self::GSPATH_NOTESTFILE;
return $ret;
}
$testimagefolder = \make_temp_directory('assignfeedback_editpdf_test');
@unlink($testimagefolder.'/image_page0.png'); // Delete any previous test images.
$pdf = new pdf();
$pdf->set_pdf($testfile);
$pdf->set_image_folder($testimagefolder);
try {
$pdf->get_image(0);
} catch (\moodle_exception $e) {
$ret->status = self::GSPATH_ERROR;
$ret->message = $e->getMessage();
}
return $ret;
}
/**
* If the test image has been generated correctly - send it direct to the browser.
*/
public static function send_test_image() {
global $CFG;
header('Content-type: image/png');
require_once($CFG->libdir.'/filelib.php');
$testimagefolder = \make_temp_directory('assignfeedback_editpdf_test');
$testimage = $testimagefolder.'/image_page0.png';
send_file($testimage, basename($testimage), 0);
die();
}
}