Swift 3: How do I enable flash on custom AVFoundation camera?

Question

I have a very basic AVFoundation Camera that has a captureButton that will take a photo and send that photo to the secondCameraController for it to be displayed. My problem is that there is a lot of iOS 10 deprecation and I'm not sure how I add in a flash when I press the captureButton. Any help will be highly appreciated. My code is below. Thank you guys.

class CameraController: UIViewController, AVCaptureVideoDataOutputSampleBufferDelegate {

let captureSession = AVCaptureSession()
var previewLayer: CALayer!

var captureDevice: AVCaptureDevice!

var takePhoto: Bool = false

override func viewDidLoad() {
    super.viewDidLoad()
    view.backgroundColor = .white
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    prepareCamera()
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    navigationController?.setNavigationBarHidden(true, animated: true)
}

let cameraView: UIView = {
    let view = UIView()
    view.backgroundColor = .red
    return view
}()

func prepareCamera() {
    captureSession.sessionPreset = AVCaptureSessionPresetPhoto

    if let availableDevices = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaTypeVideo, position: .back).devices {

        captureDevice = availableDevices.first
        beginSession()
    }
}

func beginSession() {
    do {
        let captureDeviceInput = try AVCaptureDeviceInput(device: captureDevice)

        captureSession.addInput(captureDeviceInput)

    } catch {

        print(error.localizedDescription)
    }

    if let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) {
        self.previewLayer = previewLayer
        self.view.layer.addSublayer(self.previewLayer)
        self.previewLayer.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height)
        previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill

        self.view.addSubview(captureButton)

        let width: CGFloat = 85
        captureButton.frame = CGRect(x: (previewLayer.frame.width / 2) - width / 2, y: (previewLayer.frame.height) - width - 25, width: width, height: 85)

        captureSession.startRunning()

        let dataOutput = AVCaptureVideoDataOutput()
        dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString): NSNumber(value: kCVPixelFormatType_32BGRA)]

        dataOutput.alwaysDiscardsLateVideoFrames = true

        if captureSession.canAddOutput(dataOutput) {
            captureSession.addOutput(dataOutput)
        }

        captureSession.commitConfiguration()

        let queue = DispatchQueue(label: "com.cheekylabsltd.camera")
        dataOutput.setSampleBufferDelegate(self, queue: queue)
    }
}

func handleCapture() {
    takePhoto = true
}

func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {

    if takePhoto {
        takePhoto = false

        if let image = self.getImageFromSampleBuffer(buffer: sampleBuffer) {
            let secondController = SecondCameraController()
            secondController.takenPhoto = image

            DispatchQueue.main.async {
                self.present(secondController, animated: true, completion: { 
                    self.stopCaptureSession()
                })
            }
        }
    }
}

func getImageFromSampleBuffer(buffer: CMSampleBuffer) -> UIImage? {

    if let pixelBuffer = CMSampleBufferGetImageBuffer(buffer) {
        let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
        let context = CIContext()

        let imageRect = CGRect(x: 0, y: 0, width: CVPixelBufferGetWidth(pixelBuffer), height: CVPixelBufferGetHeight(pixelBuffer))

        if let image = context.createCGImage(ciImage, from: imageRect) {
            return UIImage(cgImage: image, scale: UIScreen.main.scale, orientation: .right)
        }
    }

    return nil
}

func stopCaptureSession() {
    self.captureSession.stopRunning()

    if let inputs = captureSession.inputs as? [AVCaptureDeviceInput] {
        for input in inputs {
            self.captureSession.removeInput(input)
        }
    }
}

lazy var captureButton: UIButton = {
    let button = UIButton(type: .system)
    button.backgroundColor = .white
    button.layer.cornerRadius = 42.5
    button.clipsToBounds = true
    button.alpha = 0.40
    button.layer.borderWidth = 4
    button.layer.borderColor = greenColor.cgColor
    button.addTarget(self, action: #selector(handleCapture), for: .touchUpInside)
    return button
}()
}

Answer 1

Try this code : Swift v3.0

private func flashOn(device:AVCaptureDevice)
    {
        do{
            if (device.hasTorch)
            {
                try device.lockForConfiguration()
                device.torchMode = .on
                device.flashMode = .on
                device.unlockForConfiguration()
            }
        }catch{
            //DISABEL FLASH BUTTON HERE IF ERROR 
            print("Device tourch Flash Error ");
        }
    }

//FOR FLASH OFF CODE

 private func flashOff(device:AVCaptureDevice)
    {
        do{
            if (device.hasTorch){
                try device.lockForConfiguration()
                device.torchMode = .off
                device.flashMode = .off
                device.unlockForConfiguration()
            }
        }catch{
            //DISABEL FLASH BUTTON HERE IF ERROR
            print("Device tourch Flash Error ");
        }
    }

// METHOD

//private let session = AVCaptureSession()

//MARK: FLASH UITLITY METHODS
    func toggleFlash() {
        var device : AVCaptureDevice!

        if #available(iOS 10.0, *) {
            let videoDeviceDiscoverySession = AVCaptureDeviceDiscoverySession(deviceTypes: [.builtInWideAngleCamera, .builtInDuoCamera], mediaType: AVMediaTypeVideo, position: .unspecified)!
            let devices = videoDeviceDiscoverySession.devices!
            device = devices.first!

        } else {
            // Fallback on earlier versions
            device = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
        }

        if ((device as AnyObject).hasMediaType(AVMediaTypeVideo))
        {
            if (device.hasTorch)
            {
                self.session.beginConfiguration()
                //self.objOverlayView.disableCenterCameraBtn();
                if device.isTorchActive == false {
                    self.flashOn(device: device)
                } else {
                    self.flashOff(device: device);
                }
                //self.objOverlayView.enableCenterCameraBtn();
                self.session.commitConfiguration()
            }
        }
    }

Answer 2

Swift 4

So there are two different behaviors to choose from in AVFoundation. One would be a capture device torch switch. Connect the torchSwitch action to some view and be sure to change CameraManager.shared.backDevice to your instance of the front or back device that provides the current input.

  @IBAction func torchSwitch(_ sender: Any) {
    guard let device = CameraManager.shared.backDevice else { return }
    guard device.isTorchAvailable else { return }
    do {
      try device.lockForConfiguration()
      device.torchMode = device.torchMode ? .off : .on
      if device.torchMode == .on {
        try device.setTorchModeOn(level: 0.7)
      }
    } catch {
      debugPrint(error)
    }
  }

AVFoundation has deprecated device.flashMode

Now to set flash, declare a variable on camera or vc. The value here will be the default.

  var flash: AVCaptureFlashMode = .off

Connect this action to some view

  @IBAction func torchSwitch(_ sender: Any) { flash = flash ? .off : .on }

Then when you want to capture an image, use AVCapturePhotoOutput and prepare the photo settings. stillCameraOutput is an instance of AVCapturePhotoOutput.

  let settings = AVCapturePhotoSettings()
  settings.flashMode = flash
  stillCameraOutput.capturePhoto(with: settings, delegate: self)