swift stop 360 degree animation - ios

Question

in my swift 2 app, i have this extension:
extension UIView {
func rotate360Degrees(duration: CFTimeInterval = 2.5, completionDelegate: AnyObject? = nil) {
let rotateAnimation = CABasicAnimation(keyPath: "transform.rotation")
rotateAnimation.fromValue = 0.0
rotateAnimation.toValue = CGFloat(M_PI * 2.0)
rotateAnimation.duration = duration
if let delegate: AnyObject = completionDelegate {
rotateAnimation.delegate = delegate
}
self.layer.addAnimation(rotateAnimation, forKey: nil)
}
}
with this code, i can rotate an image 360 degree.
now i would like to stop this animation directly after i pressed on a button.
in my view controller is an action for my button. if i press this button, the following value will set:
self.shouldStopRotating = true
and i have this code part in the same vc, too:
override func animationDidStop(anim: CAAnimation, finished flag: Bool) {
if self.shouldStopRotating == false {
self.LoadingCircle.rotate360Degrees(completionDelegate: self)
}
}
the image will stop after i pressed the button, but it will stop after the animation will be finished (after 360 degrees) - but this is to late.
the image have to stop rotating directly on the actual position after i press the button

Answer 1

Try to add this when the button that stops the animation is presse:
self.LoadingCircle.layer.removeAllAnimations()
let currentLayer = self.LoadingCircle.layer.presentationLayer();
let currentRotation = currentLayer?.valueForKeyPath("transform.rotation.z")?.floatValue;
let rotation = CGAffineTransformMakeRotation(CGFloat(currentRotation!));
self.LoadingCircle.transform = rotation;