session-ios/Session/Shared/ScanQRCodeWrapperVC.swift

final class ScanQRCodeWrapperVC : BaseVC {
    var delegate: (UIViewController & OWSQRScannerDelegate)? = nil
    var isPresentedModally = false
    private let message: String
    private let scanQRCodeVC = OWSQRCodeScanningViewController()
    
    // MARK: Settings
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask { return .portrait }
    
    // MARK: Lifecycle
    init(message: String) {
        self.message = message
        super.init(nibName: nil, bundle: nil)
    }
    
    required init?(coder: NSCoder) {
        preconditionFailure("Use init(message:) instead.")
    }
    
    override init(nibName: String?, bundle: Bundle?) {
        preconditionFailure("Use init(message:) instead.")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Set up navigation bar if needed
        if isPresentedModally {
            navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .stop, target: self, action: #selector(close))
        }
        setUpGradientBackground()
        // Set up scan QR code VC
        scanQRCodeVC.scanDelegate = delegate
        let scanQRCodeVCView = scanQRCodeVC.view!
        view.addSubview(scanQRCodeVCView)
        scanQRCodeVCView.pin(.leading, to: .leading, of: view)
        scanQRCodeVCView.pin(.trailing, to: .trailing, of: view)
        scanQRCodeVCView.autoPinEdge(.top, to: .top, of: view)
        scanQRCodeVCView.autoPinToSquareAspectRatio()
        // Set up bottom view
        let bottomView = UIView()
        view.addSubview(bottomView)
        bottomView.pin(.top, to: .bottom, of: scanQRCodeVCView)
        bottomView.pin(.leading, to: .leading, of: view)
        bottomView.pin(.trailing, to: .trailing, of: view)
        bottomView.pin(.bottom, to: .bottom, of: view)
        // Set up explanation label
        let explanationLabel = UILabel()
        explanationLabel.text = message
        explanationLabel.textColor = Colors.text
        explanationLabel.font = .systemFont(ofSize: Values.smallFontSize)
        explanationLabel.numberOfLines = 0
        explanationLabel.lineBreakMode = .byWordWrapping
        explanationLabel.textAlignment = .center
        bottomView.addSubview(explanationLabel)
        explanationLabel.autoPinWidthToSuperview(withMargin: 32)
        explanationLabel.autoPinHeightToSuperview(withMargin: 32)
        // Title
        title = "Scan QR Code"
    }
    
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        UIDevice.current.ows_setOrientation(.portrait)
        DispatchQueue.main.async { [weak self] in
            self?.scanQRCodeVC.startCapture()
        }
    }
    
    // MARK: Interaction
    @objc private func close() {
        presentingViewController?.dismiss(animated: true, completion: nil)
    }
    
    public func startCapture() {
        DispatchQueue.main.async { [weak self] in
            self?.scanQRCodeVC.startCapture()
        }
    }
}