Club Drupal

<?php

/**

 * @file

 * Adaptive Image - Adaptive images for Drupal

 * @see http://adaptive-images.com/

 *

 * @author

 * Stefan Auditor <stefan.auditor@erdfisch.de>

 */

/**

 * Implements hook_init().

 */

function adaptive_image_init() {

  // According to the documentation of hook_init() it should not be used to

  // load JS or CSS. The CSS case has been moved to the info file. But the JS is

  // here by intention, as we want it inline to prevent wait time while loading

  // the script

  // No need for drupal behaviours, jquery compatibility wrapper nor ready event

  $js = "document.cookie = 'adaptive_image=' + Math.max(screen.width, screen.height) + '; path=/';";

  drupal_add_js($js,

    // First-come, first-served

    array(

      'type' => 'inline',

      'scope' => 'header',

      'group' => JS_LIBRARY,

      'every_page' => TRUE,

      'weight' => -500,

    )

  );

}

/**

 * Implements hook_menu().

 */

function adaptive_image_menu() {

  $items = array();

  // Add image style generation paths adaptive URLs.

  if (module_exists('image')) {

    // Generate and deliver image derivatives of public files.

    $directory_path = file_stream_wrapper_get_instance_by_scheme('public')->getDirectoryPath();

    $items[$directory_path . '/styles/%image_style/adaptive-image'] = array(

      'title' => 'Generate image style',

      'page callback' => 'adaptive_image_style_deliver',

      'page arguments' => array(count(explode('/', $directory_path)) + 1),

      'access callback' => TRUE,

      'type' => MENU_CALLBACK,

      'file' => 'adaptive_image.image.inc',

    );

    // Generate and deliver image derivatives of private files.

    $items['system/files/styles/%image_style/adaptive-image'] = array(

      'title' => 'Generate adaptive image style',

      'page callback' => 'adaptive_image_style_deliver',

      'page arguments' => array(3),

      'access callback' => TRUE,

      'type' => MENU_CALLBACK,

      'file' => 'adaptive_image.image.inc',

    );

  }

  return $items;

}

/**

 * Implements hook_image_effect_info().

 */

function adaptive_image_image_effect_info() {

  $effects = array();

  $effects['adaptive_image'] = array(

    'label' => t('Adaptive'),

    'help' => t('Adaptive image scale according to client resolution.'),

    'effect callback' => 'image_scale_effect',

    'dimensions callback' => 'image_scale_dimensions',

    'form callback' => 'adaptive_image_scale_form',

    'summary theme' => 'adaptive_image_scale_summary',

  );

  return $effects;

}

/**

 * Form structure for the image scale form.

 *

 * Note that this is not a complete form, it only contains the portion of the

 * form for configuring the scale options. Therefore it does not not need to

 * include metadata about the effect, nor a submit button.

 *

 * @param $data

 *   The current configuration for this scale effect.

 */

function adaptive_image_scale_form($data) {

  $form['resolutions'] = array(

    '#type' => 'textfield',

    '#title' => t('Resolutions'),

    '#default_value' => isset($data['resolutions']) ? $data['resolutions'] : '1382, 992, 768, 480',

    '#required' => TRUE,

    '#description' => t('The resolution break-points to use (screen widths, in pixels).'),

  );

  $form['mobile_first'] = array(

    '#type' => 'checkbox',

    '#title' => t('Mobile first'),

    '#default_value' => isset($data['mobile_first']) ? $data['mobile_first'] : TRUE,

    '#description' => t("Check this to send the smallest version when the resolution can not be determined."),

  );

  $resolutions = explode(',', str_replace(' ', '', $form['resolutions']['#default_value']));

  $resolution = adaptive_image_resolution($resolutions);

  // Provide needed defaults

  $form['height']  = array('#type' => 'hidden','#default_value' => NULL);

  $form['width']   = array('#type' => 'hidden','#default_value' => $resolution);

  $form['upscale'] = array('#type' => 'hidden','#default_value' => NULL);

  return $form;

}

/**

 * Implements hook_theme().

 */

function adaptive_image_theme() {

  return array(

    'adaptive_image_scale_summary' => array(

      'variables' => array('data' => NULL),

    ),

  );

}

/**

 * Returns HTML for a summary of an image scale effect.

 *

 * @param $variables

 *   An associative array containing:

 *   - data: The current configuration for this scale effect.

 *

 * @ingroup themeable

 */

function theme_adaptive_image_scale_summary($variables) {

  $data = $variables['data'];

  if ($data['resolutions']) {

    return check_plain($data['resolutions']);

  }

}

/**

 * Implements template_preprocess_image().

 *

 * Adds a class to adaptive images for max-width.

 */

function adaptive_image_preprocess_image(&$variables) {

  global $base_url;

  if (isset($variables['style_name'])) {

    // Get image style settings

    $style = image_style_load($variables['style_name']);

    // Check if style contains the adaptive image effect

    if ($style && adaptive_image_contains_effect($style)) {

      $settings = adaptive_image_effect_settings($style);

      $resolutions = explode(',', $settings['resolutions']);

      $resolution = adaptive_image_resolution($resolutions);

      // Only construct direct path if not private

      if (!strpos($variables['path'], '/system/') && is_numeric($resolution)) {

        $path_parts = pathinfo($variables['path']);

        $derivative_uri = $path_parts['dirname'] . '/' . $resolution . '/' . $path_parts['basename'];

      }

      if (isset($derivative_uri) && file_exists(str_replace($base_url, '.', $derivative_uri))) {

        // Deliver existing path to bypass menu callback

        $variables['path'] = $derivative_uri;

      }

      else {

        // Reconstruct the image path to %/%style_name/adaptive-image/% to

        // trigger image generation or file access check

        $variables['path'] = str_replace('styles/' . $variables['style_name'], 'styles/' . $variables['style_name'] . '/adaptive-image', $variables['path']);

      }

      // Add class for styling

      $variables['attributes']['class'] = 'adaptive-image';

      // Remove fixed image dimensions

      unset($variables['height']);

      unset($variables['width']);

    }

  }

}

/**

 * Check for adaptive image effect from style

 */

function adaptive_image_contains_effect($style) {

  foreach ($style['effects'] as $effect) {

    if ($effect['name'] == 'adaptive_image') {

      return TRUE;

    }

  }

  return FALSE;

}

/**

 * Get adaptive image effect from style settings

 */

function adaptive_image_effect_settings($style) {

  $settings = array();

  foreach ($style['effects'] as $effect) {

    if ($effect['name'] == 'adaptive_image') {

      $settings = $effect['data'];

    }

  }

  return $settings;

}

/**

 * Determine current resolution

 */

function adaptive_image_resolution($resolutions) {

  $resolution = '';

  /* Check to see if a valid cookie exists */

  if (count($resolutions) && isset($_COOKIE['adaptive_image'])) {

    if (is_numeric($_COOKIE['adaptive_image'])) {

      $client_width = (int) $_COOKIE['adaptive_image']; // store the cookie value in a variable

      /* the client width in the cookie is valid, now fit that number into the correct resolution break point */

      rsort($resolutions); // make sure the supplied break-points are in reverse size order

      $resolution = $resolutions[0]; // by default it's the largest supported break-point

      foreach ($resolutions as $break_point) { // filter down

        if ($client_width <= $break_point) {

          $resolution = $break_point;

        }

      }

    } else {

      setcookie("adaptive_image", "", time() -1); // delete the mangled cookie

    }

  }

  return $resolution;

}