/**
* Generates a preview for the stored image file
*
* @param stored_file $file the image we want to preview
* @param string $mode preview mode, eg. 'thumb'
* @return string|bool false if a problem occurs, the thumbnail image data otherwise
*/
protected function create_imagefile_preview(stored_file $file, $mode)
{
global $CFG;
require_once $CFG->libdir . '/gdlib.php';
if ($mode === 'tinyicon') {
$data = $file->generate_image_thumbnail(24, 24);
} else {
if ($mode === 'thumb') {
$data = $file->generate_image_thumbnail(90, 90);
} else {
if ($mode === 'bigthumb') {
$data = $file->generate_image_thumbnail(250, 250);
} else {
throw new file_exception('storedfileproblem', 'Invalid preview mode requested');
}
}
}
return $data;
}
/**
* Resize the image, if required, then generate an img tag and, if required, a link to the full-size image
* @param stored_file $file the image file to process
* @param int $maxwidth the maximum width allowed for the image
* @param int $maxheight the maximum height allowed for the image
* @return string HTML fragment to add to the label
*/
function label_generate_resized_image(stored_file $file, $maxwidth, $maxheight)
{
global $CFG;
$fullurl = moodle_url::make_draftfile_url($file->get_itemid(), $file->get_filepath(), $file->get_filename());
$link = null;
$attrib = array('alt' => $file->get_filename(), 'src' => $fullurl);
if ($imginfo = $file->get_imageinfo()) {
// Work out the new width / height, bounded by maxwidth / maxheight
$width = $imginfo['width'];
$height = $imginfo['height'];
if (!empty($maxwidth) && $width > $maxwidth) {
$height *= (double) $maxwidth / $width;
$width = $maxwidth;
}
if (!empty($maxheight) && $height > $maxheight) {
$width *= (double) $maxheight / $height;
$height = $maxheight;
}
$attrib['width'] = $width;
$attrib['height'] = $height;
// If the size has changed and the image is of a suitable mime type, generate a smaller version
if ($width != $imginfo['width']) {
$mimetype = $file->get_mimetype();
if ($mimetype === 'image/gif' or $mimetype === 'image/jpeg' or $mimetype === 'image/png') {
require_once $CFG->libdir . '/gdlib.php';
$data = $file->generate_image_thumbnail($width, $height);
if (!empty($data)) {
$fs = get_file_storage();
$record = array('contextid' => $file->get_contextid(), 'component' => $file->get_component(), 'filearea' => $file->get_filearea(), 'itemid' => $file->get_itemid(), 'filepath' => '/', 'filename' => 's_' . $file->get_filename());
$smallfile = $fs->create_file_from_string($record, $data);
// Replace the image 'src' with the resized file and link to the original
$attrib['src'] = moodle_url::make_draftfile_url($smallfile->get_itemid(), $smallfile->get_filepath(), $smallfile->get_filename());
$link = $fullurl;
}
}
}
} else {
// Assume this is an image type that get_imageinfo cannot handle (e.g. SVG)
$attrib['width'] = $maxwidth;
}
$img = html_writer::empty_tag('img', $attrib);
if ($link) {
return html_writer::link($link, $img);
} else {
return $img;
}
}
