/**
* Create the URL for a preview image including a query parameter.
*
* @param \Drupal\image\Entity\ImageStyle $style
* The image style being previewed.
* @param \Drupal\file\Entity\File $image
* The image being previewed.
* @param string $focal_point_value
* The focal point being previewed in the format XxY where x and y are the
* left and top offsets in percentages.
*
* @return \Drupal\Core\GeneratedUrl|string
* The URL of the preview image.
*/
protected function buildUrl(ImageStyle $style, File $image, $focal_point_value) {
$url = $style->buildUrl($image->getFileUri());
$url .= (strpos($url, '?') !== FALSE ? '&' : '?') . 'focal_point_preview_value=' . $focal_point_value;
return $url;
}
