Swift Continuous Rotation Animation not so continuous

Question

Here is my code. Intent is to continuously rotate the UIImageView named swirls[l]. However, there is a small pause between every rotation start/end. I have gone through every single animation tutorial but cant figure out what the mistake is?

let fullRotation = CGFloat(M_PI * 2)

    let duration = 2.0
    let delay = 0.0
    let options = UIViewKeyframeAnimationOptions.Repeat | UIViewKeyframeAnimationOptions.CalculationModeLinear

    UIView.animateKeyframesWithDuration(duration, delay: delay, options: options, animations: {
        UIView.addKeyframeWithRelativeStartTime(0, relativeDuration: 1/3, animations: {
            swirls[l].transform = CGAffineTransformMakeRotation(1/3 * fullRotation)
        })
        UIView.addKeyframeWithRelativeStartTime(1/3, relativeDuration: 1/3, animations: {
            swirls[l].transform = CGAffineTransformMakeRotation(2/3 * fullRotation)
        })
        UIView.addKeyframeWithRelativeStartTime(2/3, relativeDuration: 1/3, animations: {
            swirls[l].transform = CGAffineTransformMakeRotation(3/3 * fullRotation)
        })

        }, completion: {finished in 
    })

EDIT: I see that it has been suggested that a previous solution is available, but it simply does not work for continuous uninterrupted rotation. The only trick that worked for me is the answer that I chose below. Thanks

Answer 1

Try below extension for swift 4.

extension UIView {
    func rotate360Degrees(duration: CFTimeInterval = 3) {
        let rotateAnimation = CABasicAnimation(keyPath: "transform.rotation")
        rotateAnimation.fromValue = 0.0
        rotateAnimation.toValue = CGFloat(Double.pi * 2)
        rotateAnimation.isRemovedOnCompletion = false
        rotateAnimation.duration = duration
        rotateAnimation.repeatCount=Float.infinity
        self.layer.add(rotateAnimation, forKey: nil)
    }
}

For start rotation.

MyView.rotate360Degrees()

And for Stop.

MyView.layer.removeAllAnimations()

You can use UIButton, UILabel and many more.

Answer 2

I'm not sure what's wrong with your code, but I've implemented continuous rotation using this method,

@IBAction func rotateView(sender: UIButton) {
    UIView.animate(withDuration: 0.5, delay: 0, options: .curveLinear, animations: { () -> Void in
        self.spinningView.transform = self.spinningView.transform.rotated(by: .pi / 2)
    }) { (finished) -> Void in
        self.rotateView(sender: sender)
    }
}