Receive device orientation notifications in Swift

Orientation

func application(application: UIApplication!, didFinishLaunchingWithOptions launchOptions: NSDictionary!) -> Bool {
        // Override point for customization after application launch.
        
        UIDevice.currentDevice().beginGeneratingDeviceOrientationNotifications()
        NSNotificationCenter.defaultCenter().addObserver(self,
            selector: "detectOrientation",
            name:UIDeviceOrientationDidChangeNotification,
            object:nil)
        
        return true
}
    
func detectOrientation() {
        switch UIDevice.currentDevice().orientation {
        case UIDeviceOrientation.Unknown:
            println("Unknown")
        case UIDeviceOrientation.Portrait:
            println("Portrait")
        case UIDeviceOrientation.PortraitUpsideDown:
            println("PortraitUpsideDown")
        case UIDeviceOrientation.LandscapeLeft:
            println("LandscapeLeft")
        case UIDeviceOrientation.LandscapeRight:
            println("LandscapeRight")
        case UIDeviceOrientation.FaceUp:
            println("FaceUp")
        case UIDeviceOrientation.FaceDown:
            println("FaceDown")
        }
}