islandora_openseadragon.module

<?php

/**
 * @file
 * Hooks and callbacks for this module.
 */

/**
 * Implements hook_menu().
 */
function islandora_openseadragon_menu() {
  return array(
    'admin/islandora/islandora_viewers/openseadragon' => array(
      'title' => 'OpenSeadragon',
      'description' => 'Configure the OpenSeadragon viewer.',
      'page callback' => 'drupal_get_form',
      'access arguments' => array('administer site configuration'),
      'page arguments' => array('islandora_openseadragon_admin'),
      'file' => 'includes/admin.form.inc',
      'type' => MENU_NORMAL_ITEM,
    ),
    'islandora/object/%islandora_object/download_clip' => array(
      'page callback' => 'islandora_openseadragon_download_clip',
      'page arguments' => array(2),
      'type' => MENU_CALLBACK,
      'access callback' => 'islandora_object_access',
      'access arguments' => array(ISLANDORA_VIEW_OBJECTS, 2),
      'load arguments' => array(2),
    ),
  );
}

/**
 * Implements hook_theme().
 */
function islandora_openseadragon_theme() {
  return array(
    'islandora_openseadragon_viewer' => array(
      'variables' => array(
        'uri' => '',
        'fedora_object' => NULL,
      ),
      'template' => 'theme/islandora-openseadragon',
    ),
    // A link for clipping JP2 datastreams via djatoka.
    'islandora_openseadragon_clipper' => array(
      'variables' => array(
        'pid' => NULL,
      ),
    ),
  );
}

/**
 * Implements hook_islandora_viewer_info().
 */
function islandora_openseadragon_islandora_viewer_info() {
  return array(
    // @XXX The element returned has a width:100% but no natural flow width; it
    // is completely dependent on it's parent.
    'islandora_openseadragon' => array(
      'label' => t('OpenSeadragon'),
        // Later we'll add DZI too.
      'description' => t('OpenSeadragon viewer with djatoka as tilesource.'),
      'configuration' => 'admin/islandora/islandora_viewers/openseadragon',
      'callback' => 'islandora_openseadragon_callback',
        // DZI has xml as mimetype? Not sure how to handle that.
      'mimetype' => array('image/jp2'),
    ),
  );
}

/**
 * Callback function for the viewer.
 *
 * @param array $params
 *   Params required by the theme. We require the keys:
 *   - jp2_url: The URL to the JP2 image.
 * @param IslandoraAbstractObject $fedora_object
 *   The object that we are viewing.
 *
 * @return string
 *   HTML repersentation of the OpenSeadragon viewer
 */
function islandora_openseadragon_callback($params = NULL, $fedora_object = NULL) {
  if (isset($params['jp2_url'])) {
    $uri = $params['jp2_url'];
    return theme('islandora_openseadragon_viewer', array('uri' => $uri, 'fedora_object' => $fedora_object));
  }
}

/**
 * Implements template_preprocess_HOOK().
 */
function template_preprocess_islandora_openseadragon_viewer(&$variables) {
  // Variable fedora_object included in results, but not used.
  $library_path = libraries_get_path('openseadragon');
  $module_path = drupal_get_path('module', 'islandora_openseadragon');
  $variables['viewer_id'] = 'islandora-openseadragon';
  $settings = array(
    'id' => $variables['viewer_id'],
    'prefixUrl' => file_create_url("$library_path/images/"),
  );

  module_load_include('inc', 'islandora_openseadragon', 'includes/utilities');
  $installed_version = islandora_openseadragon_get_installed_version();

  if (version_compare($installed_version, '0.9.82') <= 0) {
    // XXX: Version numbers don't quite line-up for the change in the nav image
    // prefix URL, so now, let the hacking begin!... Just for compatibility
    // with older versions.
    $types = array('zoomIn', 'zoomOut', 'home', 'fullpage', 'previous', 'next');
    $actions = array(
      'REST' => 'rest',
      'GROUP' => 'grouphover',
      'HOVER' => 'hover',
      'DOWN' => 'pressed',
    );
    foreach ($types as $type) {
      foreach ($actions as $action => $namepart) {
        $settings['navImages'][$type][$action] = format_string('!type_!action.png', array(
          '!type' => strtolower($type),
          '!action' => $namepart,
        ));
      }
    }
  }

  $settings = array_merge($settings, islandora_openseadragon_get_settings());
  foreach ($settings as $key => $val) {
    if (filter_var($val, FILTER_VALIDATE_FLOAT)) {
      $settings[$key] = (float) $val;
    }
    elseif (filter_var($val, FILTER_VALIDATE_INT)) {
      $settings[$key] = (int) $val;
    }
    elseif (filter_var($val, FILTER_VALIDATE_URL)) {
      $settings[$key] = check_url($val);
    }
  }

  // This is where we jam in some HOCR coordinates.
  if (isset($variables['fedora_object']) && isset($_GET['solr'])) {
    $params = $_GET['solr']['params'];
    $params['fq'][] = format_string('PID:"!pid"', array(
      '!pid' => $variables['fedora_object']->id,
    ));
    module_load_include('inc', 'islandora_paged_content', 'includes/highlighting');
    $highlighting_info = islandora_paged_content_perform_solr_highlighting_query($_GET['solr']['query'], $params);
    $highlights = array();

    foreach ($highlighting_info as $pid => $info) {
      if (array_key_exists('snippets', $info)) {
        foreach ($info['snippets'] as $snippet => $bounding_boxes) {
          foreach ($bounding_boxes as $bounding_box) {
            // The size on the x axis is used to calculate the proportional
            // values under the openseadragon coordinate system.
            $highlights[] = array(
              'x' => $bounding_box['left'] / $info['page']['width'],
              'y' => $bounding_box['top'] / $info['page']['width'],
              'width' => ($bounding_box['right'] - $bounding_box['left']) / $info['page']['width'],
              'height' => ($bounding_box['bottom'] - $bounding_box['top']) / $info['page']['width'],
              'className' => "islandora-openseadragon-highlight",
            );
          }
        }
      }
    }
    $settings['overlays'] = $highlights;
  }

  drupal_add_js(array(
      'islandoraOpenSeadragon' => array(
        'pid' => isset($variables['fedora_object']) ? $variables['fedora_object']->id : NULL,
        'resourceUri' => $variables['uri'],
        'tileSize' => (int) variable_get('islandora_openseadragon_tile_size', '256'),
        'tileOverlap' => (int) variable_get('islandora_openseadragon_tile_overlap', '0'),
        'fitToAspectRatio' => variable_get('islandora_openseadragon_fit_to_aspect_ratio', FALSE),
        'settings' => $settings,
      ),
    ), 'setting');
  drupal_add_js("$library_path/openseadragon.js", array('weight' => -4));
  drupal_add_js("$module_path/js/islandora_openseadragon.js", array('weight' => -3));
  drupal_add_js("$module_path/js/djtilesource.js", array('weight' => -2));
  drupal_add_css("$module_path/css/islandora_openseadragon.theme.css");
}

/**
 * Get OpenSeadragon settings.
 *
 * @return array
 *   Configuration options for OpenSeadragon.
 */
function islandora_openseadragon_get_settings() {
  return variable_get('islandora_openseadragon_settings', array()) + array(
    'debugMode' => FALSE,
    'djatokaServerBaseURL' => '/adore-djatoka/resolver',
    'animationTime' => '1.5',
    'blendTime' => '0.1',
    'alwaysBlend' => FALSE,
    'autoHideControls' => TRUE,
    'immediateRender' => FALSE,
    'wrapHorizontal' => FALSE,
    'wrapVertical' => FALSE,
    'wrapOverlays' => FALSE,
    'panHorizontal' => TRUE,
    'panVertical' => TRUE,
    'minZoomImageRatio' => '0.8',
    'maxZoomPixelRatio' => '2',
    'visibilityRatio' => '0.5',
    'springStiffness' => '5.0',
    'imageLoaderLimit' => '5',
    'clickTimeThreshold' => '300',
    'clickDistThreshold' => '5',
    'zoomPerClick' => '2.0',
    'zoomPerScroll' => '1.2',
    'zoomPerSecond' => '2.0',
    'showNavigator' => TRUE,
    'defaultZoomLevel' => '1.0',
  );
}

/**
 * Implements hook_process_theme().
 */
function islandora_openseadragon_preprocess_islandora_object_print(array &$variables) {
  if (isset($_GET['clip'])) {
    module_load_include('inc', 'islandora_openseadragon', 'includes/utilities');
    $clip_parts = islandora_openseadragon_construct_clip_url($_GET['clip']);
    if ($clip_parts) {
      $variables['clip'] = $clip_parts['original_params'];
      $variables['content']['clip'] = array(
        '#weight' => 0,
        '#prefix' => "<div id='clip'>",
        '#markup' => theme_image(array(
                     'path' => $clip_parts['djatoka_image_url'], 'attributes' => $clip_parts['dimensions'])),
        '#suffix' => '</div>',
      );
    }
    else {
      drupal_set_message(t('Invalid clip parameters passed.'), 'error');
    }
  }
}


/**
 * Theme function to create a clipper link.
 */
function theme_islandora_openseadragon_clipper(&$variables) {
  $image = theme(
    'image',
    array(
      'path' => drupal_get_path('module', 'islandora_openseadragon') . '/images/clip_icon.png',
    )
  );
  return l(
    $image,
    "islandora/object/{$variables['pid']}/print",
    array(
      'attributes' => array(
        'title' => t('Clip Image'),
        'id' => 'clip',
      ),
      'html' => TRUE,
    )
  );
}

/**
 * Menu callback downloads the given clip.
 *
 * @param AbstractObject $object
 *   An AbstractObject representing an object within Fedora.
 */
function islandora_openseadragon_download_clip(AbstractObject $object) {
  if (isset($_GET['clip'])) {
    module_load_include('inc', 'islandora_openseadragon', 'includes/utilities');
    $clip_parts = islandora_openseadragon_construct_clip_url($_GET['clip'], TRUE);
    if ($clip_parts) {
      $filename = $object->label;
      header("Content-Disposition: attachment; filename=\"{$filename}.jpg\"");
      header("Content-type: image/jpeg");
      header("Content-Transfer-Encoding: binary");
      $ch = curl_init();
      curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
      curl_setopt($ch, CURLOPT_HEADER, 0);
      curl_setopt($ch, CURLOPT_URL, $clip_parts['djatoka_image_url']);
      curl_exec($ch);
      curl_close($ch);
    }
    else {
      drupal_access_denied();
      watchdog('islandora_openseadragon', 'Invalid parameters specified for downloading of a clip for @pid. Parameters attempted: @params.', array(
        '@pid' => $object->id,
        '@params' => $_GET['clip'],
      ));
    }
  }
  exit();
}