Get current iOS device orientation even if device's orientation locked

Question

I want to get the current iOS device orientation even if device's orientation is locked. (Just like iOS Camera app)

I want to detect Portrait, Landscape Left and Landscape Right at least.

UIDeviceOrientation and UIInterfaceOrientation do not seem to work when orientation is locked.

In this case, I think that we will use CoreMotion.

How do i logic it in swift4?

Answer 1

Declare motion manager with Core Motion

    var orientationLast = UIInterfaceOrientation(rawValue: 0)!
    var motionManager: CMMotionManager?

Motion manager initialization

and call this function in viewDidLoad

    func initializeMotionManager() {
     motionManager = CMMotionManager()
     motionManager?.accelerometerUpdateInterval = 0.2
     motionManager?.gyroUpdateInterval = 0.2
     motionManager?.startAccelerometerUpdates(to: (OperationQueue.current)!, withHandler: {
        (accelerometerData, error) -> Void in
        if error == nil {
            self.outputAccelerationData((accelerometerData?.acceleration)!)
        }
        else {
            print("\(error!)")
        }
        })
     }   

To analyze accelerometer data

 func outputAccelerationData(_ acceleration: CMAcceleration) {
    var orientationNew: UIInterfaceOrientation
    if acceleration.x >= 0.75 {
        orientationNew = .landscapeLeft
        print("landscapeLeft")
    }
    else if acceleration.x <= -0.75 {
        orientationNew = .landscapeRight
        print("landscapeRight")
    }
    else if acceleration.y <= -0.75 {
        orientationNew = .portrait
        print("portrait")
        
    }
    else if acceleration.y >= 0.75 {
        orientationNew = .portraitUpsideDown
        print("portraitUpsideDown")
    }
    else {
        // Consider same as last time
        return
    }
    
    if orientationNew == orientationLast {
        return
    }
    orientationLast = orientationNew
}