BlockManager::getTheme PHP Method

    private function getTheme()
    {
        $currentTheme = Config::inst()->get('SSViewer', 'theme');
        // check directly on SiteConfig incase ContentController hasn't set
        // the theme yet in ContentController->init()
        if (!$currentTheme && class_exists('SiteConfig')) {
            $currentTheme = SiteConfig::current_site_config()->Theme;
        }
        return $currentTheme ? $currentTheme : 'default';
    }