Paper for Facebook image scroll in Xamarin.iOS

public override void ViewDidLoad ()
{
	base.ViewDidLoad ();
	
	// Perform any additional setup after loading the view, typically from a nib.
	mainScrollView.Bounces = false;
	mainScrollView.UserInteractionEnabled = false;

	var movingImageView = new UIImageView (UIImage.FromFile ("landscape.jpg"));
	mainScrollView.AddSubview (movingImageView);

	mainScrollView.ContentSize = new SizeF (movingImageView.Frame.Width, mainScrollView.Frame.Height);
	mainScrollView.ContentOffset = new PointF ((float)(mainScrollView.ContentSize.Width - View.Frame.Width) / 2.0f, 0);

	motionManager = new CMMotionManager ();
	motionManager.GyroUpdateInterval = 1 / 60.0;

	// this is how fast the image should move when rotate the device
	var motionMovingRate = 4;
	var shakeThreshold = 0.1;

	//get the max and min offset x value
	var maxXOffset = mainScrollView.ContentSize.Width - mainScrollView.Frame.Width;
	var minXOffset = 0;

	motionManager.StartGyroUpdates (NSOperationQueue.CurrentQueue, (CMGyroData gyroData, NSError error) => {
		if (Math.Abs (gyroData.RotationRate.y) >= shakeThreshold) 
		{
			var targetX = mainScrollView.ContentOffset.X - gyroData.RotationRate.y * motionMovingRate;

			if (targetX > maxXOffset)
						targetX = maxXOffset;
			else if (targetX < minXOffset)
						targetX = minXOffset;

			mainScrollView.ContentOffset = new PointF ((float)targetX, 0);
		}
	});
}