How do you stop ui objects being covered when a Date picker selector pops up in swift

Question

How would I move two buttons from the bottom of the screen to the top of a datepicker when it appears when the user goes to enter their birthday? I know there's code to make UI items move when a keyboard shows up, in fact that's already in my code:

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)

@objc func keyboardWillShow(notification: NSNotification) {
    guard let userInfo = notification.userInfo else {return}
    guard let keyboardSize = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {return}
    let keyboardFrame = keyboardSize.cgRectValue
    let animationDurarion = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! TimeInterval
    UIView.animate(withDuration: animationDurarion, animations: { () -> Void in
        self.backButton_constrant.constant += keyboardFrame.height
        self.nextButton_constrant.constant += keyboardFrame.height
        self.view.layoutIfNeeded()
    })
}

@objc func keyboardWillHide(notification: NSNotification){
    guard let userInfo = notification.userInfo else {return}
    guard let keyboardSize = userInfo[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue else {return}
    let keyboardFrame = keyboardSize.cgRectValue
    let animationDurarion = userInfo[UIResponder.keyboardAnimationDurationUserInfoKey] as! TimeInterval
    UIView.animate(withDuration: animationDurarion, animations: { () -> Void in
        self.backButton_constrant.constant -= keyboardFrame.height
        self.nextButton_constrant.constant -= keyboardFrame.height
        self.view.layoutIfNeeded()
    })

I'm just wondering how I'd do the same, but this time moving the two buttons when the date picker pops up, basically, is there an observer for date pickers?

Here's what my app looks like to make it a bit more understandable

Thanks

UPDATE: FULL CODE:

import UIKit

class birthday_createAccountViewController: UIViewController, UITextFieldDelegate {

    var email = String()
    @IBOutlet weak var birthday_input: UITextField!
    @IBOutlet weak var backButton_constraint: NSLayoutConstraint!
    @IBOutlet weak var nextButton_constraint: NSLayoutConstraint!

    private var datePicker: UIDatePicker?

    override func viewDidLoad() {
        super.viewDidLoad()

        self.birthday_input.delegate = self
        birthday_input.underlined()

        datePicker = UIDatePicker()
        datePicker?.datePickerMode = .date
        birthday_input.inputView = datePicker
        datePicker?.addTarget(self, action: #selector(birthday_createAccountViewController.dateChanged(datePicker:)), for: .valueChanged)


        NotificationCenter.default.addObserver(self, selector: #selector(keyboard(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboard(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboard(notification:)), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)


        // Do any additional setup after loading the view.
    }

    @objc func dateChanged(datePicker: UIDatePicker){

        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "dd/MM/yyyy"
        birthday_input.text = dateFormatter.string(from: datePicker.date)
    }


    @objc func keyboard(notification: NSNotification){
        let rect = ((notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue)
        let keyboardHeight = rect?.height

        if notification.name.rawValue == "UIKeyboardWillShowNotification" {
            if UIDatePicker.isEditing == true { //change this for your picker
                UIView.animate(withDuration: 1) {
                    self.backButton_constraint.constant += keyboardHeight!
                    self.nextButton_constraint.constant += keyboardHeight!
                    self.view.layoutIfNeeded()
                }
            } else {
                UIView.animate(withDuration: 1) {
                    self.backButton_constraint.constant -= keyboardHeight!
                    self.nextButton_constraint.constant -= keyboardHeight!
                    self.view.layoutIfNeeded()
                }
            }
        } else {
            UIView.animate(withDuration: 1) {
                self.backButton_constraint.constant -= keyboardHeight!
                self.nextButton_constraint.constant -= keyboardHeight!
                self.view.layoutIfNeeded()
            }
        }

    }
}

Answer 1

you need to add Observers like you did for different ocations

private func setObservers() {
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(sender:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(sender:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChange(sender:)), name: NSNotification.Name.UIKeyboardWillChangeFrame, object: nil)       
    }

1.- UIKeyboardWillShow 2.- UIKeyboardWillHide 3.- UIKeyboardWillChangeFrame

So the observers will run background while the user performs actions //this piece of code is from one of my projects us it as example

 // Métodos que se ejecutan cuando aparece o desaparece el teclado
    @objc func keyboardWillChange(sender: Notification) {
        print(sender.name.rawValue)

        // Se almacena el rect del teclado, el origen en xy su ancho y su alto
        let rect = ((sender.userInfo![UIKeyboardFrameEndUserInfoKey] as AnyObject).cgRectValue)
        let keyboardHeight = rect?.height

        if sender.name.rawValue == "UIKeyboardWillShowNotification" {
            if Uipcikerdate.isEditing == true { //change this for your picker 
                print("se está editando tokenfield")
                UIView.animate(withDuration: 1) {
                    self.topAnc.isActive = false
                    self.botAnc.isActive = false
                    self.topAnc = self.interface.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor, constant: -(keyboardHeight!))
                    self.botAnc = self.interface.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor, constant: -(keyboardHeight!))
                    self.topAnc.isActive = true
                    self.botAnc.isActive = true
                    self.interface.layoutIfNeeded()
                }
            } else {
                UIView.animate(withDuration: 1) {
                    self.topAnc.isActive = false
                    self.botAnc.isActive = false
                    self.botAnc = self.interface.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor)
                    self.topAnc = self.interface.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor)
                    self.topAnc.isActive = true
                    self.botAnc.isActive = true
                    self.interface.layoutIfNeeded()
                }
            }
        } else {
            UIView.animate(withDuration: 1) {
                self.topAnc.isActive = false
                self.botAnc.isActive = false
                self.botAnc = self.interface.bottomAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.bottomAnchor)
                self.topAnc = self.interface.topAnchor.constraint(equalTo: self.view.safeAreaLayoutGuide.topAnchor)
                self.topAnc.isActive = true
                self.botAnc.isActive = true
                self.interface.layoutIfNeeded()
            }
        }

    }