Text View Rotate

class RotateTextViewVC: UIViewController {

    let tv = UITextView()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .systemYellow

        tv.isScrollEnabled = false
        tv.text = "This is some sample text for the text view."
        tv.font = .systemFont(ofSize: 24.0, weight: .regular)

        // add a slider to rotate the text view
        let slider = UISlider()
        slider.addTarget(self, action: #selector(sliderChanged(_:)), for: .valueChanged)

        slider.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(slider)

        tv.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(tv)

        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([
            slider.topAnchor.constraint(equalTo: g.topAnchor, constant: 40.0),
            slider.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            slider.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),

            tv.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            tv.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            tv.widthAnchor.constraint(equalToConstant: 200.0),
        ])

        slider.value = 0.5
    }
    @objc func sliderChanged(_ sender: UISlider) {

        let deg: CGFloat = (CGFloat(sender.value) - 0.5) * 720.0
        let radians = deg * .pi / 180.0
        tv.layer.transform = CATransform3DRotate(CATransform3DIdentity, radians, 0, 0, 1)

    }

}