How can I call a custom function when the return button is pressed within a UITextView?

Question

I'm trying to debug a problem where pressing the return key doesn't trigger a text view change and as a result messes with my NSAttributedString inside of my UITextView. Whenever I press the return button my UITextView calculates the number of lines and for whatever reason thinks the image is only 1 line.

Answer 1

You can call a custom function with the textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String).

class ViewController: UIViewController, UITextViewDelegate {

    @IBOutlet weak var textView: UITextView!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        textView.delegate = self
    }

    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {

        if text == "\n" {
            print("new line")
            // Call your custom function
        }

        return true
    }