사진 촬영 기능 구현하기

final class ViewController: UIViewController {
    @IBOutlet weak var imageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func tapped(_ sender: Any) {
        // 사진 촬영 버튼
    }
}

final class ViewController: UIViewController {

    @IBOutlet weak var imageView: UIImageView!
    lazy var imagePickerController: UIImagePickerController = {
        let imagePickerController: UIImagePickerController = UIImagePickerController()
        imagePickerController.sourceType = .camera
        imagePickerController.allowsEditing = true
        imagePickerController.delegate = self
        return imagePickerController
    }()

    // 생략 ...
}

switch AVCaptureDevice.authorizationStatus(for: .video) {
    case .authorized: // 권한 허용
        present(imagePickerController, animated: true)
    case .notDetermined: // 권한 요청을 받은 적이 없음
        AVCaptureDevice.requestAccess(for: .video) { [weak self] granted in
        guard let self = self else { return }
            if granted {
                DispatchQueue.main.async {
                    self.present(self.imagePickerController, animated: true)
                }
            }
        }
    // 생략 ...
}

/// 사용자에게 카메라 촬영 권한에 관한 알럿을 표시한다.
func showMoveSettingAlert() {
    let alert: UIAlertController = UIAlertController(title: "",
                                                    message: "카메라 촬영 권한이 없습니다.\n카메라 권한을 허용해주세요.",
                                                    preferredStyle: .alert)
    let cancleAction: UIAlertAction = UIAlertAction(title: "취소",
                                                    style: .cancel,
                                                    handler: nil)
    let settingAction: UIAlertAction = UIAlertAction(title: "설정",
                                                    style: .default,
                                                    handler: { [weak self] _ in
        self?.moveAppSetting()
    })

    alert.addAction(cancleAction)
    alert.addAction(settingAction)
    present(alert, animated: true, completion: nil)
}

/// 앱 설정 화면으로 이동한다.
func moveAppSetting() {
    guard let url = URL(string: UIApplication.openSettingsURLString) else { return }

    if UIApplication.shared.canOpenURL(url) {
        UIApplication.shared.open(url)
    }
}

// 사진 촬영 버튼 선택 시
@IBAction func tapped(_ sender: Any) {
    switch AVCaptureDevice.authorizationStatus(for: .video) {
        // 생략 ...
        case .denied, .restricted: // 권한 요청 거부, 제한
            showMoveSettingAlert()
        @unknown default: // 그 외
            showMoveSettingAlert()
    }
}

extension ViewController: UINavigationControllerDelegate, UIImagePickerControllerDelegate {
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        picker.dismiss(animated: true) // 편집이 끝났으므로 UIImagePickerController를 닫는다.

        // 편집된 이미지를 가져온다.
        guard let image = info[.editedImage] as? UIImage else {
            print("No image found")
            return
        }

        // imageView에 이미지를 지정한다.
        imageView.image = image
    }
}

extension UIImagePickerController {
    open override var childForStatusBarHidden: UIViewController? {
        return nil
    }

    open override var prefersStatusBarHidden: Bool {
        return true
    }

    open override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        fixCannotMoveEditingBox()
    }

    func fixCannotMoveEditingBox() {
        if let cropView = cropView,
           let scrollView = scrollView,
           scrollView.contentOffset.y == 0 {

            let top: CGFloat = cropView.frame.minY
            let bottom = scrollView.frame.height - cropView.frame.height - top
            scrollView.contentInset = UIEdgeInsets(top: top, left: 0, bottom: bottom, right: 0)

            var offset: CGFloat = 0
            if scrollView.contentSize.height > scrollView.contentSize.width {
                offset = 0.5 * (scrollView.contentSize.height - scrollView.contentSize.width)
            }
            scrollView.contentOffset = CGPoint(x: 0, y: -top + offset)
        }

        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) { [weak self] in
            self?.fixCannotMoveEditingBox()
        }
    }

    var cropView: UIView? {
        return findCropView(from: self.view)
    }

    var scrollView: UIScrollView? {
        return findScrollView(from: self.view)
    }

    func findCropView(from view: UIView) -> UIView? {
        let width = UIScreen.main.bounds.width
        let size = view.bounds.size
        if width == size.height, width == size.height {
            return view
        }
        for view in view.subviews {
            if let cropView = findCropView(from: view) {
                return cropView
            }
        }
        return nil
    }

    func findScrollView(from view: UIView) -> UIScrollView? {
        if let scrollView = view as? UIScrollView {
            return scrollView
        }
        for view in view.subviews {
            if let scrollView = findScrollView(from: view) {
                return scrollView
            }
        }
        return nil
    }
}