A simple iOS record button writing in Swift

    @IBOutlet weak var recordButton: RecordButton!
    override func viewDidAppear(_ animated: Bool) {

        super.viewDidAppear(animated)

        recordButton.delegate = self
    }

    var recordButton: RecordButton?
    override func viewDidAppear(_ animated: Bool) {

        super.viewDidAppear(animated)

        let recordButtonSide = self.view.bounds.size.height/10
        recordButton = RecordButton(frame: CGRect(x: self.view.bounds.width/2-recordButtonSide/2,
                                                  y: self.view.bounds.height/2-recordButtonSide/2,
                                                  width: recordButtonSide,
                                                  height: recordButtonSide))
        recordButton?.delegate = self

        self.view.addSubview(recordButton!)

    }

extension ViewController: RecordButtonDelegate {

    func tapButton(isRecording: Bool) {

        if isRecording {
            print("Start recording")
        } else {
            print("Stop recording")
        }
    }
}