BarcodeViewController

BarcodeViewController.swift

class BarcodeViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {

    var delegate: BarcodeDelegate?
    var captureSession: AVCaptureSession!
    var code: String?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // You use an AVCaptureSession object to coordinate the flow of data from AV input devices to outputs.
        self.captureSession = AVCaptureSession();
        
        // Get the Video device
        let videoCaptureDevice: AVCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
        
        var error: NSError?
        // Use to capture data from an AVCaptureDevice object.
        let videoInput = AVCaptureDeviceInput.deviceInputWithDevice(videoCaptureDevice, error: &error) as AVCaptureDeviceInput
        
        // Add the input to the session if possible
        if self.captureSession.canAddInput(videoInput) {
            self.captureSession.addInput(videoInput)
        } else {
            println("Could not add video input: \(error?.localizedDescription)")
        }
        
        // Add the output to the session if possible
        let metadataOutput = AVCaptureMetadataOutput()
        if self.captureSession.canAddOutput(metadataOutput) {
            self.captureSession.addOutput(metadataOutput)
            
            // Add ourselves as delegate to get the output
            metadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
            metadataOutput.metadataObjectTypes = [AVMetadataObjectTypeQRCode, AVMetadataObjectTypeEAN13Code]
        } else {
            println("Could not add metadata output")
        }
        
        
        // Create a preview layer to add it to the ViewController's view
        let previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
        previewLayer.frame = self.view.layer.bounds
        self.view.layer.addSublayer(previewLayer)
        
        // Start the session
        self.captureSession.startRunning()
        
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
    // This is the delegate'smethod that is called when a code is readed 
        for metadata in metadataObjects {
            let readableObject = metadata as AVMetadataMachineReadableCodeObject
            let code = readableObject.stringValue
            
            // If the code is not empty the code is ready and we call out delegate to pass the code.
            if !code.isEmpty {
                self.captureSession.stopRunning()
                self.dismissViewControllerAnimated(true, completion: nil)
                self.delegate?.barcodeReaded(code)
            }
        }
    }
}