Move a view up only when the keyboard covers an input field

MoveScreenDependsOnKeyboard.swift

class Welcome: UIViewController {

    @IBOutlet weak var tfEMail: TextField!
    @IBOutlet weak var tfPassword: TextField!
    
    private var activeTextField: UITextField?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        registerForKeyboardNotifications()
    }
    
    override func viewDidDisappear(_ animated: Bool) {
        deregisterFromKeyboardNotifications()
        super.viewDidDisappear(animated)
    }
}

private extension Welcome {
    func setupUIComponents() {
        tfEMail.tfText.returnKeyType = .done
        tfPassword.tfText.returnKeyType = .done
        
        tfEMail.tfText.delegate = self
        tfPassword.tfText.delegate = self
    }
    
    func registerForKeyboardNotifications() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
    }
    
    func deregisterFromKeyboardNotifications() {
        NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
    }
    
    @objc func keyboardWillShow(notification: NSNotification) {
        let info: Dictionary = notification.userInfo!
        if let keyboardSize = (info[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size {
            if let activeTextField = activeTextField {
                let realActiveTextFieldFrame = activeTextField.convert(activeTextField.frame, to: self.view)
                let textFieldHeightDiff = realActiveTextFieldFrame.origin.y + realActiveTextFieldFrame.height
                let keyboardHeightDiff = self.view.frame.height - keyboardSize.height
                let viewMoveDiff = keyboardHeightDiff - textFieldHeightDiff
                
                if viewMoveDiff < 0 {
                    self.view.transform = CGAffineTransform(translationX: 0, y: viewMoveDiff)
                }
            }
        }
    }
    
    @objc func keyboardWillHide(notification: NSNotification) {
        self.view.transform = CGAffineTransform.identity
    }
}

extension Welcome: UITextFieldDelegate {
    func textFieldDidBeginEditing(_ textField: UITextField) {
        activeTextField = textField
    }
    
    func textFieldDidEndEditing(_ textField: UITextField) {
        activeTextField = nil
    }
    
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        return textField.resignFirstResponder()
    }
}

Your message give me motivation :) Me thanks !