var activeField: UITextField? = nil

    func registerForKeyboardNotifications(){
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }

    func removeForKeyboardNotifications(){
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }

    @objc func keyboardWillShow(notification: Notification) {
        guard activeField != nil else {
            return
        }

        let userInfo = notification.userInfo
        let kbFrameSize = (userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue.size

        let contentInsets = UIEdgeInsetsMake(0.0, 0.0, kbFrameSize.height, 0.0)
        scrollView.contentInset = contentInsets
        scrollView.scrollIndicatorInsets = contentInsets

        var aRect = self.view.frame
        aRect.size.height -= kbFrameSize.height
        if (!aRect.contains(activeField!.frame.origin)) {
            scrollView.scrollRectToVisible(activeField!.frame, animated: true)
        }
    }

    @objc func keyboardWillHide(notification: Notification) {
        let contentInsets = UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0)
        scrollView.contentInset = contentInsets
        scrollView.scrollIndicatorInsets = contentInsets
    }

    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        activeField = textField;
        return true
    }

    func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {
        activeField = nil;
        return true
    }