Method _bind

client/scripts/ui.js:480–488

(notification, handler)

    }

    _bind(notification, handler) {
        if (notification.then) {
            notification.then(e => serviceWorker.getNotifications().then(notifications => {
                serviceWorker.addEventListener('notificationclick', handler);
            }));
        } else {
            notification.onclick = handler;
        }
    }
}