Is UITextField+UIPickerView supported under Mac Catalyst? - uitextfield

Question

In my iOS app I have a textfield with a picker view assigned to it's inputView. On iOS devices the picker view pops up whenever the user taps the textfield. The same code does not do that, however, when I run it as a Mac/Catalyst app. My debug effort so far shows that the picker view methods are not called at all, so if the Mac requires additional textfield delegate methods to take focus away from the Mac's keyboard? Any idea how to make this work on a Mac? A barebones example code is below.
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource, UITextFieldDelegate {
#IBOutlet weak var myTextField: UITextField!
var myPickerView : UIPickerView!
var pickerData = ["Alpha" , "Bravo" , "Charlie" , "Delta"]
override func viewDidLoad() {
super.viewDidLoad()
self.myPickerView = UIPickerView(frame:CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: 300))
self.myPickerView.delegate = self
self.myPickerView.dataSource = self
self.myTextField.delegate = self
self.myTextField.inputView = self.myPickerView
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return pickerData.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return pickerData[row]
}
}

Answer 1

It looks like a bug in Mac Catalyst. Try using the UIPicker embedded in an UIActionSheet. ActionSheetPicker-3.0 is a ready-made solution. Show the ActionSheetPicker in textFieldDidBeginEditing of your UITextField.

Answer 2

ViewController
class ViewController : UIViewController {
// MARK: - Properties -
var tableView : UITableView?
var currentTextfield : UITextField?
var gendersArray : Array<String> = ["Male", "Female"]
var pickerView : UIPickerView?
// MARK: - Lifecycle -
override func viewDidLoad() {
super.viewDidLoad()
// get the size of the iOS device
let screenRect : CGRect = UIScreen.main.bounds
let screenWidth : CGFloat = screenRect.size.width
let screenHeight : CGFloat = screenRect.size.height
// add the picker view
var pickerViewFrame = CGRect(x: 0.0,
y: screenHeight - 162.0,
width: screenWidth,
height: 162.0)
// set pickerview frame for macOS Catalyst
#if targetEnvironment(macCatalyst)
pickerViewFrame = CGRect(x: 0, y: 0, width: 269, height: 240)
#endif
pickerView = UIPickerView.init(frame: pickerViewFrame)
pickerView?.delegate = self
pickerView?.dataSource = self
// ... set tableview
}
}
UIAlertController Function
// MARK: - UIAlertController -
#objc func textfieldInputAction(pickerView: UIPickerView, textfield: UITextField?) {
print("textfieldInputAction")
// alertController
let alertController = UIAlertController(title: "Title of Action Sheet", message: "", preferredStyle: UIAlertController.Style.actionSheet)
// reload components
pickerView.reloadAllComponents()
// add the picker to the alert controller
alertController.view.addSubview(pickerView)
// set height of Action sheet
let height : NSLayoutConstraint = NSLayoutConstraint(item: alertController.view!, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 350)
alertController.view.addConstraint(height)
// okAction
let okAction = UIAlertAction(title: "Done", style: .default, handler: {
(alert: UIAlertAction!) -> Void in
// end editing
DispatchQueue.main.async {
textfield?.resignFirstResponder()
DispatchQueue.main.async {
UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
}
}
})
alertController.addAction(okAction)
// popoverController
if let popoverController = alertController.popoverPresentationController {
popoverController.sourceView = textfield //to set the source of your alert
popoverController.sourceRect = textfield?.bounds ?? CGRect(x: 0, y: 0, width: 0, height: 0 )
popoverController.permittedArrowDirections = [.down, .up]
}
// present alertController
self.present(alertController, animated: true, completion: nil)
}
TableView
// MARK: - Tableview -
extension ViewController : UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell : TextFieldCell = tableView.dequeueReusableCell(withIdentifier: "TextFieldCell", for: indexPath) as! TextFieldCell
// textfield
cell.textField?.delegate = self
cell.textField?.inputView = pickerView
return cell
}
}
UITextField Delegate
// MARK: - UITextField -
extension ViewController : UITextFieldDelegate {
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
print("textFieldShouldBeginEditing")
#if targetEnvironment(macCatalyst)
if textField.inputView == self.pickerView {
self.currentTextfield = textField
self.textfieldInputAction(pickerView: self.pickerView!, textfield: self.currentTextfield!)
return false
}
#endif
return true
}
}
UIPickerView Delegate
// MARK: - PickerView Delegates -
extension ViewController : UIPickerViewDelegate, UIPickerViewDataSource {
// components
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
// rows
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
print("numberOfRowsInComponent")
return gendersArray.count
}
// title
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return gendersArray[row]
}
// select row
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
print("pickerView: didSelectRow: \(row)")
currentTextfield?.text = gendersArray[row]
self.tableView?.reloadData()
}
}

Answer 3

This is a bit of a hack, but let me share anyway. If you listen for the NSNotification UIKeyboardWillChangeFrameNotification
this will fire before -(BOOL)textFieldShouldBeginEditing:(UITextField *)textField
so you can set a BOOL to see if this method fires. If it doesn't, you can tell that you don't have a software keyboard, and then can show an alert controller or context menu, or however you want to handle it differently.

Answer 4

On UIPickerViewMioPicker.swift
class UIPickerViewMio : NSObject, UIPickerViewDataSource, UIPickerViewDelegate {
private var uiTextField : UITextField?
private var oggetto = ["Uno", "Due", "Tre", "Quattro", "Cinque"]
required init(uiTextField : UITextField?) {
self.uiTextField = uiTextField
}
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return 5
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
if let textField = self.uiTextField {
textField.text = self.oggetto[row]
textField.tag = row
}
}
... omissis ...}
On UIViewController
#IBOutlet var textMioText : UITextField?
var uiPickerViewMioPicker : UIPickerViewMioPicker?
override func viewDidLoad() {
... omissis ...
self.uiPickerViewMio = UIPickerViewMioPicker(uiTextField: self.textMioText)
let pickerM = UIPickerView()
pickerM.delegate = self.uiPickerViewMioPicker
pickerM.dataSource = self.uiPickerViewMioPicker
self.textMioText?.inputView = pickerM
... omissis ...
}
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
if textField == self.textMio {
let picker = textField.inputView as! UIPickerView
picker.isHidden = false
if UIDevice.current.systemName == "Mac OS X" {
let alertPicker = UIAlertController(title: "", message: "", preferredStyle: UIAlertController.Style.actionSheet)
alertPicker.view.addSubview(picker)
alertPicker.view.addConstraint(NSLayoutConstraint(item: alertPicker.view!, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: picker.bounds.height * 1.1))
alertPicker.view.addConstraint(NSLayoutConstraint(item: alertPicker.view!, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: picker.bounds.width * 1.1))
if let popoverController = alertPicker.popoverPresentationController {
popoverController.sourceView = textField
popoverController.sourceRect = textField.bounds
popoverController.permittedArrowDirections = [.down, .up]
}
self.present(alertPicker, animated: true, completion: nil)
return false
}
}
return true}