bsp_openseadragon.module

<?php

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

/**
 * Implements hook_menu().
 */
function bsp_openseadragon_menu() {
  return array(
    'admin/config/media/openseadragon' => array(
      'title' => 'OpenSeadragon',
      'description' => 'Configure the OpenSeadragon viewer.',
      'page callback' => 'drupal_get_form',
      'access arguments' => array('administer site configuration'),
      'page arguments' => array('bsp_openseadragon_admin'),
      'file' => 'includes/admin.form.inc',
      'type' => MENU_NORMAL_ITEM,
    ),
    'openseadragon/viewer' => array(
      'type' => MENU_CALLBACK,
      'access callback' => TRUE,
      'page callback' => 'bsp_openseadragon_viewer_page',
    ),
  );
}

/**
 * Implements hook_theme().
 */
function bsp_openseadragon_theme() {
  return array(
    'bsp_openseadragon_viewer' => array(
      'variables' => array(
        'uri' => '',
      ),
      'template' => 'theme/bsp-openseadragon',
    ),
  );
}

/**
 * Implements hook_bsp_viewer_info().
 */
function bsp_openseadragon_bsp_viewer_info() {
  return array(
    'bsp_openseadragon' => array(
      'label' => t('OpenSeadragon'),
      'description' => t('OpenSeadragon viewer with an IIIF-compatible as Tile Source.'),
      'configuration' => 'admin/config/media/openseadragon',
      'callback' => 'bsp_openseadragon_callback',
      'mimetype' => array('image/jp2'),
    ),
  );
}

/**
* Implements hook_field_formatter_info().
*/
function bsp_openseadragon_field_formatter_info() {
  return array(
    'textfield_openseadragon' => array(
      'label' => t('OpenSeadragon text field URI viewer'),
      'field types' => array('text'),
    ),
  );
}

/**
* Implements hook_field_formatter_view().
*/
function bsp_openseadragon_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = array();
  switch ($display['type']) {
    case 'textfield_openseadragon':
      if (!empty($items[0])) {
        $library_path = libraries_get_path('openseadragon');
        $module_path = drupal_get_path('module', 'bsp_openseadragon');
        $settings = bsp_openseadragon_add_settings();
        $params = array(
          'bspOpenSeadragon' => array(
            'resourceUri' => _get_iiif_uri($items[0]['value']),
            'tileSize' => (int) variable_get('bsp_openseadragon_tile_size', '256'),
            'tileOverlap' => (int) variable_get('bsp_openseadragon_tile_overlap', '0'),
            'settings' => $settings),
        );

        drupal_add_js($params, 'setting');
        drupal_add_js("$library_path/openseadragon.js");
        drupal_add_js("$module_path/js/bsp_openseadragon.js");
        drupal_add_css("$module_path/css/bsp_openseadragon.theme.css");

        $element[0] = array(
          '#markup' => '<div id="bsp-openseadragon" class="bsp-openseadragon bsp-openseadragon--field-formatter"></div>',
        );
      }

      break;
  }
  return $element;
}

/**
 * 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 bspAbstractObject $fedora_object
 *   The object that we are viewing.
 *
 * @return string
 *   HTML repersentation of the OpenSeadragon viewer
 */
function bsp_openseadragon_callback($params = NULL, $fedora_object = NULL) {
  if (isset($params['jp2_url'])) {
    $uri = $params['jp2_url'];
    return theme('bsp_openseadragon_viewer', array('uri' => $uri, 'fedora_object' => $fedora_object));
  }
}

/**
 * Implements hook_preprocess().
 */
function bsp_openseadragon_preprocess_bsp_openseadragon_viewer(&$variables) {
  $variables['viewer_id'] = 'bsp-openseadragon';
  $settings = bsp_openseadragon_add_settings();
  // This is where we jam in some HOCR coordinates.
  if (isset($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', 'bsp_paged_content', 'includes/highlighting');
    $highlighting_info = bsp_paged_content_perform_solr_highlighting_query($_GET['solr']['query'], $params);
    $highlights = array();

    foreach ($highlighting_info as $pid => $info) {
      foreach ($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' => "bsp-openseadragon-highlight",
          );
        }
      }
    }
    $settings['overlays'] = $highlights;
  }

  drupal_add_js(array(
      'bspOpenSeadragon' => array(
        'pid' => isset($variables['fedora_object']) ? $variables['fedora_object']->id : NULL,
        'resourceUri' => _get_iiif_uri($variables['uri']),
        'tileSize' => (int) variable_get('bsp_openseadragon_tile_size', '256'),
        'tileOverlap' => (int) variable_get('bsp_openseadragon_tile_overlap', '0'),
        'settings' => $settings,
      ),
    ), 'setting');
  drupal_add_js("$module_path/js/bsp_openseadragon.js");
  drupal_add_js("$library_path/openseadragon.js");
  drupal_add_css("$module_path/css/bsp_openseadragon.theme.css");
}

function bsp_openseadragon_add_settings() {
  // Variable fedora_object included in results, but not used.
  $library_path = libraries_get_path('openseadragon');
  $module_path = drupal_get_path('module', 'bsp_openseadragon');
  $settings = array(
    'id' => 'bsp-openseadragon',
    'prefixUrl' => file_create_url("$module_path/images/"),
    'navigatorPosition' => 'TOP_RIGHT',
  );

  module_load_include('inc', 'bsp_openseadragon', 'includes/utilities');
  $installed_version = bsp_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, bsp_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;
    }
  }

  return $settings;
}

/**
 * Get OpenSeadragon settings.
 *
 * @return array
 *   Configuration options for OpenSeadragon.
 */
function bsp_openseadragon_get_settings() {
  return variable_get('bsp_openseadragon_settings', array(
      'debugMode' => FALSE,
      '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,
    )
  );
}

/**
 * Implements hook_process_theme().
 */
function bsp_openseadragon_preprocess_bsp_object_print(array &$variables) {
  $object = $variables['object'];
  if (isset($_GET['clip'])) {
    $dimensions = array();
    if (isset($_GET['dimensions'])) {
      $dimensions = explode(',', $_GET['dimensions']);
      $dimensions = array(
        'width' => $dimensions[0],
        'height' => $dimensions[1],
      );
    }
    $variables['clip'] = $clip = $_GET['clip'];
    $variables['content']['clip'] = array(
      '#weight' => 0,
      '#prefix' => "<div id='clip'>",
      '#markup' => theme_image(array(
                   'path' => $_GET['clip'], 'attributes' => $dimensions)),
      '#suffix' => '</div>',
    );
  }
}

/**
 * Page callback to display a seadragon viewer.
 *
 * @param null $id
 * @return array|string
 */
function bsp_openseadragon_viewer_page($id = NULL) {
  if (!$id) {
    return '';
  }

  $library_path = libraries_get_path('openseadragon');
  $module_path = drupal_get_path('module', 'bsp_openseadragon');
  $settings = bsp_openseadragon_add_settings();

  $params = array(
    'bspOpenSeadragon' => array(
      'resourceUri' => _get_iiif_uri($id),
      'tileSize' => (int) variable_get('bsp_openseadragon_tile_size', '256'),
      'tileOverlap' => (int) variable_get('bsp_openseadragon_tile_overlap', '0'),
      'settings' => $settings),
  );

  drupal_add_js($params, 'setting');
  drupal_add_js("$library_path/openseadragon.js");
  drupal_add_js("$module_path/js/bsp_openseadragon.js");
  drupal_add_css("$module_path/css/bsp_openseadragon.theme.css");

  $output = array(
    '#markup' => '<div id="bsp-openseadragon" class="bsp-openseadragon bsp-openseadragon--viewer-page"></div>',
  );

  return $output;
}

/**
 * Helper function to convert an Islandora uri into an iiif uri.
 */
function _get_iiif_uri($string) {
  $islandora = preg_quote('https://dl.library.ucla.edu/islandora/object/', '/');
  $iiif_prefix = 'https://dl.library.ucla.edu/iiif/2/';
  $iiif_suffix = '~JP2~~default';
  if (strpos($string, $iiif_prefix) === 0) {
    $result = $string;
  }
  else if (preg_match("/^$islandora(?<pid>.*)$/", $string, $matches)) {
    $pid = $matches['pid'];
    $result = $iiif_prefix . $pid . $iiif_suffix;
  }
  else {
    $pid = $string;
    $result = $iiif_prefix . $pid . $iiif_suffix;
  }
  return $result;
}