KeyboardObserver.swift

let keyboard = KeyboardObserver()

override func viewDidLoad() {
    super.viewDidLoad()

    keyboard.observe { [weak self] (event) -> Void in
        guard let self = self else { return }
        switch event.type {
        case .willShow, .willHide, .willChangeFrame:
            // React to the keyboard and adapt your UI
            updateInsets(for: event, scrollView: self.scrollView)
        default:
            break
        }
    }
}