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<?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/>.
/**
* Icon set class for format tiles.
* @package format_tiles
* @copyright 2019 David Watson {@link http://evolutioncode.uk} in respect of modifications to format_grid versions by G J Barnard.
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
namespace format_tiles;
defined('MOODLE_INTERNAL') || die();
global $CFG;
// PHP image processing library.
require_once($CFG->libdir . '/gdlib.php');
/**
* Class image_processor
* @package format_tiles
* @copyright 2018 David Watson {@link http://evolutioncode.uk} in respect of modifications to format_grid versions by G J Barnard.
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class image_processor
{
/**
* When the user uploads a new file, it is saved as tempfile which may be large.
* This takes the temp file and adds an adjusted version to the tile_photo object.
* @param \stored_file $tempfile
* @param string $newfilename
* @param \context_course $coursecontext
* @param int $sectionid
* @param int $width
* @param int $height
* @return \stored_file|bool
* @throws \file_exception
* @throws \required_capability_exception
* @throws \stored_file_creation_exception
*/
public static function adjust_and_copy_file($tempfile, $newfilename, $coursecontext, $sectionid, $width, $height) {
require_capability('moodle/course:update', $coursecontext);
$newfilename = str_replace(' ', '_', $newfilename);
$storedfilerecord = self::stored_file_record($coursecontext->id, $sectionid, $newfilename);
$fs = get_file_storage();
try {
// Ensure the right quality setting...
$mime = $tempfile->get_mimetype();
$storedfilerecord['mimetype'] = $mime;
$tmproot = make_temp_directory('formattilesphoto');
$tmpfilepath = $tmproot . '/' . $tempfile->get_contenthash();
$tempfile->copy_content_to($tmpfilepath);
$data = self::process_image($tmpfilepath, $width, $height, $mime);
if (!empty($data)) {
// If a file exists with the same details (e.g. teacher uploading new file with same name), delete it.
$existingfile = $fs->get_file(
$storedfilerecord['contextid'],
$storedfilerecord['component'],
$storedfilerecord['filearea'],
$storedfilerecord['itemid'],
$storedfilerecord['filepath'],
$storedfilerecord['filename']
);
if ($existingfile) {
debugging('Deleted old photo' . $existingfile->get_id(), DEBUG_DEVELOPER);
$existingfile->delete();
}
// Create new file.
$newfile = $fs->create_file_from_string($storedfilerecord, $data);
unlink($tmpfilepath);
unset($tempfile);
return $newfile;
} else {
debugging('imagecannotbeused', 'format_tiles', DEBUG_DEVELOPER);
}
} catch (Exception $e) {
if (isset($tempfile)) {
unset($tempfile);
}
debugging('Format tiles image exception:...', DEBUG_DEVELOPER);
debugging($e->getMessage(), DEBUG_DEVELOPER);
return false;
}
return false;
}
/**
* For a given image, which may be very large, scale it so it's size is correct for use as a tile background.
* This is based on generate_image() in format_grid.
*
* If the GD library has at least version 2 and PNG support is available, the returned data
* is the content of a transparent PNG file containing the thumbnail. Otherwise, the function
* returns contents of a JPEG file with black background containing the thumbnail.
*
* @param string $filepath the full path to the original image file
* @param int $requestedwidth the width of the requested image.
* @param int $requestedheight the height of the requested image.
* @param string $mime The mime type.
* @return string|bool false if a problem occurs or the image data.
*/
private static function process_image($filepath, $requestedwidth, $requestedheight, $mime) {
$imagecontainerbgcolour = array('r' => 255, 'g' => 255, 'b' => 255);
if (empty($filepath) or empty($requestedwidth) or empty($requestedheight)) {
return false;
}
$imageinfo = getimagesize($filepath);
if (empty($imageinfo)) {
return false;
}
$originalwidth = $imageinfo[0];
$originalheight = $imageinfo[1];
if (empty($originalwidth) or empty($originalheight)) {
return false;
}
$original = imagecreatefromstring(file_get_contents($filepath));
$imageparams = self::get_image_params($mime);
if (function_exists('imagecreatetruecolor')) {
$tempimage = imagecreatetruecolor($requestedwidth, $requestedheight);
if ($imageparams['function'] === 'imagepng') {
imagealphablending($tempimage, false);
imagefill($tempimage, 0, 0, imagecolorallocatealpha(
$tempimage,
0,
0,
0,
127
));
imagesavealpha($tempimage, true);
} else if (array_search($imageparams['function'], array('imagejpeg', 'imagewebp', 'imagegif')) !== false) {
imagealphablending($tempimage, false);
imagefill(
$tempimage,
0,
0,
imagecolorallocate(
$tempimage,
$imagecontainerbgcolour['r'],
$imagecontainerbgcolour['g'],
$imagecontainerbgcolour['b']
)
);
}
} else {
$tempimage = imagecreate($requestedwidth, $requestedheight);
}
$finalimage = $tempimage;
$ratio = min($requestedwidth / $originalwidth, $requestedheight / $originalheight);
if ($ratio < 1) {
$targetwidth = floor($originalwidth * $ratio);
$targetheight = floor($originalheight * $ratio);
} else {
// Do not enlarge the original file if it is smaller than the requested thumbnail size.
$targetwidth = $originalwidth;
$targetheight = $originalheight;
}
$dstx = floor(($requestedwidth - $targetwidth) / 2);
$dsty = floor(($requestedheight - $targetheight) / 2);
imagecopybicubic($finalimage, $original, $dstx, $dsty, 0, 0, $targetwidth, $targetheight, $originalwidth,
$originalheight);
ob_start();
if (!$imageparams['function']($finalimage, null, $imageparams['quality'], $imageparams['filters'])) {
ob_end_clean();
return false;
}
$data = ob_get_clean();
imagedestroy($original);
imagedestroy($finalimage);
return $data;
}
/**
* When we are storing a new image as a file for this object, the data we should use for the Moodle File API.
* @param int $contextid the context id (course context) for the file.
* @param int $sectionid the section id for the file.
* @param string $filename the filename we are storing as
* @return array the data to use with the API.
*/
private static function stored_file_record($contextid, $sectionid, $filename) {
global $USER;
$created = time();
return array_merge(
tile_photo::file_api_params(),
array(
'contextid' => $contextid,
'itemid' => $sectionid,
'filename' => $filename,
'timecreated' => $created,
'timemodified' => $created,
'userid' => $USER->id
)
);
}
/**
* For a given image mimetype, get the parameters we need to process the image.
* Also check that the gd function exists in this environment.
* I.e. what gd function do we use and what quality level.
* This is based on generate_image() in format_grid.
* @param string $mime
* @return array|bool
*/
private static function get_image_params($mime) {
switch ($mime) {
case 'image/png':
if (function_exists('imagepng')) {
return array(
'function' => 'imagepng',
'filters' => PNG_NO_FILTER,
'quality' => 1
);
break;
}
case 'image/jpeg':
if (function_exists('imagejpeg')) {
return array(
'function' => 'imagejpeg',
'filters' => null,
'quality' => 90
);
break;
}
case 'image/webp':
if (function_exists('imagewebp')) {
return array(
'function' => 'imagewebp',
'filters' => null,
'quality' => 90
);
break;
}
case 'image/gif':
if (function_exists('imagegif')) {
return array(
'function' => 'imagegif',
'filters' => null,
'quality' => null
);
break;
}
default:
debugging('Mime type \''.$mime.'\' is not supported as an image format. PNG, JPEG and GIF are supported. '
. 'The GD PHP extension should be installed.');
return false;
}
}
}