class ThemeUpdater

hook_updater_info in core/modules/system/system.api.php

Provide information on Updaters (classes that can update Backdrop).

system_autoload_info in core/modules/system/system.module

Implements hook_autoload_info().

system_updater_info in core/modules/system/system.module

Implements hook_updater_info().

class ThemeUpdater extends Updater {

  /**
   * Return the directory where a theme should be installed.
   *
   * If the theme is already installed, backdrop_get_path() will return
   * a valid path and we should install it there (although we need to use an
   * absolute path, so we prepend BACKDROP_ROOT). If we're installing a new
   * theme, we always want it to go into /themes, since that's
   * where all the documentation recommends users install their themes, and
   * there's no way that can conflict on a multi-site installation, since
   * the Update manager won't let you install a new theme if it's already
   * found on your system, and if there was a copy in top-level, we'd see it.
   */
  public function getInstallDirectory() {
    if ($relative_path = backdrop_get_path('theme', $this->name)) {
      $relative_path = dirname($relative_path);
    }
    elseif (file_exists(BACKDROP_ROOT . '/themes/contrib')) {
      $relative_path = 'themes/contrib';
    }
    else {
      $relative_path = 'themes';
    }
    return realpath(BACKDROP_ROOT) . '/' . $relative_path;
  }

  public function isInstalled() {
    return (bool) backdrop_get_path('theme', $this->name);
  }

  public static function canUpdateDirectory($directory) {
    return (self::getProjectType($directory) == 'theme');
  }

  public static function canUpdate($project_name) {
    return (bool) backdrop_get_path('theme', $project_name);
  }

  public function postInstall() {
    // Update the system table.
    clearstatcache();
    system_rebuild_theme_data();
  }

  public function postInstallTasks() {
    return array(
      l(t('Enable newly added themes'), 'admin/appearance'),
      l(t('Browse more themes'), 'admin/appearance/install'),
    );
  }
}