sailing-analytics/SAPTracker/QRCodeViewController.swift

//
//  QRCodeViewController.swift
//  SAPTracker
//
//  Created by computing on 22/10/14.
//  Copyright (c) 2014 com.sap.sailing. All rights reserved.
//

import UIKit
import AVFoundation

class QRCodeViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
    struct NotificationType {
        static let qrcodeScannedNotificationKey = "qrcode_scanned"
    }

    @IBOutlet weak var previewView: UIView!
    var session: AVCaptureSession!
    var previewLayer: AVCaptureVideoPreviewLayer!

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

    @IBAction func dismiss(sender: AnyObject) {
        self.dismissViewControllerAnimated(true, completion: nil)
    }
    
    @IBAction func startScanning() {
        var device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
        
        var writeError : NSError? = nil
        var input = AVCaptureDeviceInput.deviceInputWithDevice(device, error: &writeError) as? AVCaptureDeviceInput
        
        var output = AVCaptureMetadataOutput()
        output.setMetadataObjectsDelegate(self,queue: dispatch_get_main_queue())
        
        session = AVCaptureSession()
        session.canSetSessionPreset(AVCaptureSessionPresetHigh)
        if session.canAddInput(input) {
            session.addInput(input)
        }
        if session.canAddOutput(output) {
            session.addOutput(output)
        }
        output.metadataObjectTypes = [AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeQRCode]
        
        previewLayer = AVCaptureVideoPreviewLayer(session: session)
        previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
        previewLayer.frame = previewView.bounds
        previewView.layer.addSublayer(previewLayer)
        
        session.startRunning()
    }
    
    func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!)
    {
        if metadataObjects.count > 0 {
            let metadataObject: AVMetadataMachineReadableCodeObject = metadataObjects[0] as AVMetadataMachineReadableCodeObject
            println(metadataObject.stringValue)
            
            if (!QRCodeManager.sharedManager.parseString(metadataObject.stringValue)) {
                var alert = UIAlertController(title: "SAP Tracker", message: "Incorrect QR Code", preferredStyle: UIAlertControllerStyle.Alert)
                alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil))
                self.presentViewController(alert, animated: true, completion: nil)
                return
            }
            
            session.stopRunning()
            previewLayer.removeFromSuperlayer()
            self.dismissViewControllerAnimated(true, completion: nil)
        }
    }
}