Swift function textfield got focus OSX - swift

Question

Currently I am having multiple textfields in a view. If the user taps at one of them there should be a function responding to the event. Is there a way on how to do react (if a textfield got the focus)? I tried it with the NSTextFieldDelegate method but there is no appropriate function for this event.
This is how my code looks at the moment:
class ViewController: NSViewController, NSTextFieldDelegate {
override func viewDidLoad() {
super.viewDidLoad()
let textField = NSTextField(frame: CGRectMake(10, 10, 37, 17))
textField.stringValue = "Label"
textField.bordered = false
textField.backgroundColor = NSColor.controlColor()
view.addSubview(textField)
textField.delegate = self
let textField2 = NSTextField(frame: CGRectMake(30, 30, 37, 17))
textField2.stringValue = "Label"
textField2.bordered = false
textField2.backgroundColor = NSColor.controlColor()
view.addSubview(textField2)
textField2.delegate = self
}
func control(control: NSControl, textShouldBeginEditing fieldEditor: NSText) -> Bool {
print("working") // this only works if the user enters a charakter
return true
}
}
The textShouldBeginEditing function only handles the event if the user tries to enter a character but this isn't what I want. It has to handle the event if he clicks on the textfield.
Any ideas, thanks a lot?
Edit
func myAction(sender: NSView)
{
print("aktuell: \(sender)")
currentObject = sender
}
This is the function I want to call.

Answer 1

1) Create a subclass of NSTextField.
import Cocoa
class MyTextField: NSTextField {
override func mouseDown(theEvent:NSEvent) {
let viewController:ViewController = ViewController()
viewController.textFieldClicked()
}
}
2) With Interface building, select the text field you want to have a focus on. Navigate to Custom Class on the right pane. Then set the class of the text field to the one you have just created.
3) The following is an example for ViewController.
import Cocoa
class ViewController: NSViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override var representedObject: AnyObject? {
didSet {
// Update the view, if already loaded.
}
}
func textFieldClicked() -> Void {
print("You've clicked on me!")
}
}
4) Adding text fields programmatically...
import Cocoa
class ViewController: NSViewController {
let myField:MyTextField = MyTextField()
override func viewDidLoad() {
super.viewDidLoad()
//let myField:MyTextField = MyTextField()
myField.setFrameOrigin(NSMakePoint(20,70))
myField.setFrameSize(NSMakeSize(120,22))
let textField:NSTextField = NSTextField()
textField.setFrameOrigin(NSMakePoint(20,40))
textField.setFrameSize(NSMakeSize(120,22))
self.view.addSubview(myField)
self.view.addSubview(textField)
}
override var representedObject: AnyObject? {
didSet {
// Update the view, if already loaded.
}
}
func textFieldClicked() -> Void {
print("You've clicked on me!")
}
}

Answer 2

I know it’s been answered some while ago but I did eventually find this solution for macOS in Swift 3 (it doesn’t work for Swift 4 unfortunately) which notifies when a textfield is clicked inside (and for each key stroke).
Add this delegate to your class:-
NSTextFieldDelegate
In viewDidLoad() add these:-
imputTextField.delegate = self
NotificationCenter.default.addObserver(self, selector: #selector(textDidChange(_:)), name: Notification.Name.NSTextViewDidChangeSelection, object: nil)
Then add this function:-
func textDidChange(_ notification: Notification) {
print("Its come here textDidChange")
guard (notification.object as? NSTextView) != nil else { return }
let numberOfCharatersInTextfield: Int = textFieldCell.accessibilityNumberOfCharacters()
print("numberOfCharatersInTextfield = \(numberOfCharatersInTextfield)")
}
Hope this helps others.