Determining which UIPicker's toolbar button sent a message - ios

Question

I am trying to use multiple UIPickers on a page. I think I've configured almost everything. When I use a UIPicker I add in a a tool bar with a "Cancel" and a "Done" Button.
The toolbars are built using the same function, so it calls the same action when a user taps "Done". A pseudo example flow below.
let pickerData: [String] = ["1", "2", "3", "4"]
var picker = UIPickerView()
let pickerData2: [String] = ["A", "B", "C", "D"]
var picker2 = UIPickerView()
#IBOutlet weak var textField: UITextField!
#IBOutlet weak var textField2: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// set up pickers
setPickerView()
}
// set the pickerview
func setPickerView(){
picker.dataSource = self
picker.delegate = self
textField.inputView = picker
textField.inputAccessoryView = initToolBar()
// second picker
picker2.dataSource = self
picker2.delegate = self
textField2.inputView = picker
textField2.inputAccessoryView = initToolBar()
}
// build the toolbar for uipicker, so a user can select a value
func initToolBar() -> UIToolbar {
let toolBar = UIToolbar()
toolBar.barStyle = UIBarStyle.default
toolBar.isTranslucent = true
toolBar.tintColor = UIColor(red:14.0/255, green:122.0/255, blue:254.0/255, alpha: 1)
toolBar.sizeToFit()
// TODO need to update actions for all buttons
let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.plain, target: self, action: nil)
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action: #selector(pickerDoneAction))
let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)
toolBar.isUserInteractionEnabled = true
return toolBar
}
func pickerDoneAction(sender: UIBarButtonItem){
/*Here I'm just updating the same textfield when the done button is
is pressed, I'm not sure how I can get the instance of the picker into this method*/
let indexPath = picker.selectedRow(inComponent: 0)
textfield.text = data[indexPath]
}
// delegates
func numberOfComponents(in pickerView: UIPickerView) -> Int { return 1 }
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == picker {
return pickerData.count
} else return pickerData2.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if pickerView == picker {
return pickerData[row]
} else return pickerData2[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == picker {
textField.text = pickerData[row]
} else textField2.text = pickerData2[row]
}
Is there a way to determine which UIPicker was being used when the done button was clicked, so I could use that instance in my pickerDoneAction method and then change the corresponding textfield's value? I tried checking if the textfield was firstResponder and even tried to check the UIPicker itself, but it didn't seem possible. Do I need to change my approach and if so how?
Update
I've added in my existing UIPicikerView delegate methods.
Just to clarify, I want the value of the UIPicker to be assigned to the correct textfield when a user presses "Done", therefore if a user wants to select the very first row from a UIPicker, it gets inserted.

Answer 1

You can implement the following UIPickerViewDelegate's method:
optional func pickerView(_ pickerView: UIPickerView,
didSelectRow row: Int,
inComponent component: Int)
where the method is Called by the picker view when the user selects a row in a component and use
pickerView
(An object representing the picker view requesting the data) to know which pickerview has been used.

Answer 2

You can always pass down data using UIView's tag property:
func setPickerView() {
picker.tag = 1
textField.inputView = picker
textField.inputAccessoryView = initToolBar(pickerTag: picker.tag)
picker2.tag = 2
textField.inputView = picker2
textField.inputAccessoryView = initToolBar(pickerTag: picker2.tag)
}
func initToolBar(pickerTag: Int) {
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.plain, target: self, action: #selector(pickerDoneAction))
doneButton.tag = pickerTag
}
func pickerDoneAction(sender: UIBarButtonItem){
let pickerView: UIPickerView
switch sender.tag {
case picker.tag: pickerView = picker
case picker2.tag: pickerView = picker2
default: return
}
}

Answer 3

You can try changing data dynamically with different conditions that you set as data source to pickerview

Answer 4

Maybe you don't need to determine which picker it is, but which text field.
In pickerDoneAction(sender:), use let textField = sender.superview.superview, where sender is the button, parent is the toolbar and the toolbar's parent is the text field. Then you fill it with pickerData[0].
Another way to achieve the same goal is to use UITextFieldDelegate's method textFieldDidEndEditing(_:). When the text field ends editing, insert the default value there.

Answer 5

let pickerData: [String] = ["1", "2", "3", "4"]
var picker = UIPickerView()
let pickerData2: [String] = ["A", "B", "C", "D"]
var picker2 = UIPickerView() // <<<<<<<<<<<<<
var userPicker:UIPickerView?
#IBOutlet weak var textField: UITextField!
#IBOutlet weak var textField2: UITextField!
.....
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
userPicker = pickerView // <<<<<<<<<<<<<
if pickerView == picker {
return pickerData[row]
} else return pickerData2[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
userPicker = pickerView // <<<<<<<<<<<<<
if pickerView == picker {
textField.text = pickerData[row]
} else textField2.text = pickerData2[row]
}

Answer 6

You can simply check which textfield is in editing state. Do this in your done clicked function. You don't have to add any tags to the pickerView or to the textField.
func pickerDoneAction(sender: UIBarButtonItem) {
if textField1.isEditing == true {
Print("pickerview 1 is selected")
} else {
Print("pickerview 2 is selected")
}
}
Hope this helps! :)