LanguageSwitcherInterface.php

<?php

namespace Drupal\language;

use Drupal\Core\Url;
use Symfony\Component\HttpFoundation\Request;

/**
 * Interface for language switcher classes.
 */
interface LanguageSwitcherInterface {
    
    /**
     * Returns language switch links.
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request.
     * @param string $type
     *   The language type.
     * @param \Drupal\Core\Url $url
     *   The URL the switch links will be relative to.
     *
     * @return array
     *   An array of link arrays keyed by language code.
     */
    public function getLanguageSwitchLinks(Request $request, $type, Url $url);

}