exif_orientation.module

<?php


/**
 * @file
 * Module file for EXIF Orientation
 */

/**
 * Implements hook_form_alter().
 * Replace the user_validate_picture validator with our own.
 */
function exif_orientation_form_user_profile_form_alter(&$form, &$form_state, $form_id) {
    $key = array_search('user_validate_picture', $form['#validate']);
    $form['#validate'][$key] = '_exif_orientation_validate_user_picture';
}

/**
 * Validates an image uploaded by a user.
 * This is an exact copy of user_validate_picture() except our validator which is added
 * before file_validate_image_resolution(). file_validate_image_resolution resizes the image
 * if it's too large loosing the exif data in the process. The standard validators of
 * hook_file_validate() are run after user_validate_picture() so it cannot be used because
 * the image does not contain the exif data anymore. The only solution is to completely replace
 * the validator from core.
 *
 * @see user_validate_picture()
 */
function _exif_orientation_validate_user_picture(&$form, &$form_state) {
    // If required, validate the uploaded picture.
    $validators = array(
        'file_validate_is_image' => array(),
        '_exif_orientation_validate_image_callback' => array(),
        'file_validate_image_resolution' => array(
            variable_get('user_picture_dimensions', '85x85'),
        ),
        'file_validate_size' => array(
            variable_get('user_picture_file_size', '30') * 1024,
        ),
    );
    // Save the file as a temporary file.
    $file = file_save_upload('picture_upload', $validators);
    if ($file === FALSE) {
        form_set_error('picture_upload', t("Failed to upload the picture image; the %directory directory doesn't exist or is not writable.", array(
            '%directory' => variable_get('user_picture_path', 'pictures'),
        )));
    }
    elseif ($file !== NULL) {
        $form_state['values']['picture_upload'] = $file;
    }
}

/**
 * Image validator which rotates the image.
 */
function _exif_orientation_validate_image_callback(stdClass $file) {
    _exif_orientation_rotate($file);
    // This validator did not produce any errors.
    return array();
}

/**
 * Implements hook_file_presave().
 */
function exif_orientation_file_presave($file) {
    // Provide EXIF Orientation correction.
    _exif_orientation_rotate($file);
}

/**
 * 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->filemime == 'image/jpeg') {
        $file_exif = @exif_read_data(drupal_realpath($file->uri));
        // 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) {
            // Load the image object for manipulation
            $file_image = image_load(drupal_realpath($file->uri));
            if (image_rotate($file_image, $degrees, 0xffffff)) {
                image_save($file_image);
            }
        }
    }
}