Rotate a view for 360 degrees indefinitely in Swift?

Question

I want to rotate an image view for 360 degrees indefinitely.

UIView.animate(withDuration: 2, delay: 0, options: [.repeat], animations: {
    self.view.transf         


        

Answer 1

Avoiding the completion closure with recursive calls!

Bit late to this party, but using UIView keyFrame animation & varying stages of rotation for each keyFrame, plus setting the animation curve works nicely. Here's an UIView class function -

class func rotate360(_ view: UIView, duration: TimeInterval, repeating: Bool = true) {

    let transform1 = CGAffineTransform(rotationAngle: .pi * 0.75)
    let transform2 = CGAffineTransform(rotationAngle: .pi * 1.5)

    let animationOptions: UInt
    if repeating {
        animationOptions = UIView.AnimationOptions.curveLinear.rawValue | UIView.AnimationOptions.repeat.rawValue
    } else {
        animationOptions = UIView.AnimationOptions.curveLinear.rawValue
    }

    let keyFrameAnimationOptions = UIView.KeyframeAnimationOptions(rawValue: animationOptions)

    UIView.animateKeyframes(withDuration: duration, delay: 0, options: [keyFrameAnimationOptions, .calculationModeLinear], animations: {
        UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 0.375) {
            view.transform = transform1
        }
        UIView.addKeyframe(withRelativeStartTime: 0.375, relativeDuration: 0.375) {
            view.transform = transform2
        }
        UIView.addKeyframe(withRelativeStartTime: 0.75, relativeDuration: 0.25) {
            view.transform = .identity
        }
    }, completion: nil)
}

Looks pretty gnarly, with the weird rotation angles, but as the op & others have found, you can't just tell it to rotate 360