class ConfigTranslationOverviewAccess

class ConfigTranslationOverviewAccess implements AccessInterface {
    
    /**
     * The mapper plugin discovery service.
     *
     * @var \Drupal\config_translation\ConfigMapperManagerInterface
     */
    protected $configMapperManager;
    
    /**
     * The language manager.
     *
     * @var \Drupal\Core\Language\LanguageManagerInterface
     */
    protected $languageManager;
    
    /**
     * Constructs a ConfigTranslationOverviewAccess object.
     *
     * @param \Drupal\config_translation\ConfigMapperManagerInterface $config_mapper_manager
     *   The mapper plugin discovery service.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager service.
     */
    public function __construct(ConfigMapperManagerInterface $config_mapper_manager, LanguageManagerInterface $language_manager) {
        $this->configMapperManager = $config_mapper_manager;
        $this->languageManager = $language_manager;
    }
    
    /**
     * Checks access to the overview based on permissions and translatability.
     *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The route_match to check against.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The account to check access for.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access(RouteMatchInterface $route_match, AccountInterface $account) {
        $mapper = $this->getMapperFromRouteMatch($route_match);
        try {
            $langcode = $mapper->getLangcode();
        } catch (ConfigMapperLanguageException $exception) {
            // ConfigTranslationController shows a helpful message if the language
            // codes do not match, so do not let that prevent granting access.
            $langcode = 'en';
        }
        $source_language = $this->languageManager
            ->getLanguage($langcode);
        return $this->doCheckAccess($account, $mapper, $source_language);
    }
    
    /**
     * Gets a configuration mapper using a route match.
     *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   The route match to populate the mapper with.
     *
     * @return \Drupal\config_translation\ConfigMapperInterface
     *   The configuration mapper.
     */
    protected function getMapperFromRouteMatch(RouteMatchInterface $route_match) {
        $mapper = $this->configMapperManager
            ->createInstance($route_match->getRouteObject()
            ->getDefault('plugin_id'));
        $mapper->populateFromRouteMatch($route_match);
        return $mapper;
    }
    
    /**
     * Checks access given an account, configuration mapper, and source language.
     *
     * Grants access if the proper permission is granted to the account, the
     * configuration has translatable pieces, and the source language is not
     * locked given it is present.
     *
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The account to check access for.
     * @param \Drupal\config_translation\ConfigMapperInterface $mapper
     *   The configuration mapper to check access for.
     * @param \Drupal\Core\Language\LanguageInterface|null $source_language
     *   The source language to check for, if any.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The result of the access check.
     */
    protected function doCheckAccess(AccountInterface $account, ConfigMapperInterface $mapper, $source_language = NULL) {
        $access = $account->hasPermission('translate configuration') && $mapper->hasSchema() && $mapper->hasTranslatable() && (!$source_language || !$source_language->isLocked());
        return AccessResult::allowedIf($access)->cachePerPermissions();
    }

}