exif_orientation.module in EXIF Orientation 8

Module file for EXIF Orientation.

File

exif_orientation.module

<?php

/**
 * @file
 * Module file for EXIF Orientation.
 */
use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\file\FileInterface;

/**
 * Implements hook_file_presave().
 */
function exif_orientation_file_presave(EntityInterface $entity) {

  // Provide EXIF Orientation correction.
  _exif_orientation_rotate($entity);
}

/**
 * Implements hook_field_widget_form_alter().
 *
 * Add a custom validator before file_validate_image_resolution().
 * file_validate_image_resolution resizes the image if it's too large losing the
 * exif data in the process.
 */
function exif_orientation_field_widget_form_alter(&$element, FormStateInterface $form_state, $context) {
  if (isset($element['#upload_validators']['file_validate_image_resolution'])) {
    $element['#upload_validators'] = [
      'exif_orientation_validate_image_rotation' => [],
    ] + $element['#upload_validators'];
  }
}

/**
 * Ensures that image orientation is according to exif data.
 *
 * @param \Drupal\file\FileInterface $file
 *   A file entity. This function may rotate the file.
 *
 * @return array
 *   An empty array.
 *
 * @see hook_file_validate()
 */
function exif_orientation_validate_image_rotation(FileInterface $file) {
  _exif_orientation_rotate($file);

  // This validator did not produce any errors.
  return [];
}

/**
 * Rotates an image to its EXIF Orientation.
 *
 * iPhone 4 and up save all images in landscape, relying on EXIF data to
 * set the orientation properly. This does not always translate well in the
 * browser or other devices.
 * @link: http://www.daveperrett.com/articles/2012/07/28/exif-orientation-handling-is-a-ghetto/
 */
function _exif_orientation_rotate($file) {
  if (function_exists('exif_read_data') && $file
    ->getMimeType() == 'image/jpeg') {
    $file_exif = @exif_read_data(\Drupal::service('file_system')
      ->realpath($file
      ->getFileUri()));

    // Ensure that the Orientation key|value exists, otherwise leave.
    if (!is_array($file_exif) || !isset($file_exif['Orientation'])) {
      return;
    }

    // Orientation numbers and corresponding degrees.
    // @note: Odd numbers are flipped images, would need different process.
    switch ($file_exif['Orientation']) {
      case 3:
        $degrees = 180;
        break;
      case 6:
        $degrees = 90;
        break;
      case 8:
        $degrees = 270;
        break;
      default:
        $degrees = 0;
    }
    if ($degrees > 0) {
      $image = \Drupal::service('image.factory')
        ->get($file
        ->getFileUri());
      if ($image
        ->rotate($degrees)) {
        $image
          ->save();
      }
    }
  }
}

Functions

Name	Description
exif_orientation_field_widget_form_alter	Implements hook_field_widget_form_alter().
exif_orientation_file_presave	Implements hook_file_presave().
exif_orientation_validate_image_rotation	Ensures that image orientation is according to exif data.
_exif_orientation_rotate	Rotates an image to its EXIF Orientation.