Set up TextFields

ViewController.swift

class ViewController {
    
    @IBOutlet weak var emailTextField: OyaRoundCornerTextField!

    @IBOutlet weak var passwordTextField: OyaRoundCornerTextField!

    // ...
  
    var textFields: [UITextField] {
        get {
            return [emailTextField,passwordTextField]
        }
    }
  
  /// ...
}

extension ViewController: UITextFieldDelegate {

    func setUpTextFields() {
        for textField in textFields {
            textField.delegate = self
        }
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        textField.text = textField.text?.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        guard let index = textFields.index(of: textField) else {
            return true
        }
        if index + 1 < textFields.count {
            let nextField = textFields[index + 1]
            nextField.becomeFirstResponder()
        } else {
            textField.resignFirstResponder()
        }

        return false
    }

    @objc func textChanged(textField: UITextField) {
        textField.text = textField.text?.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    func resignTextFieldFirstResponder() {
        for textField in textFields {
            textField.resignFirstResponder()
        }
    }
}