Jessica Kimble
Jessica Kimble

Reputation: 545

Reverse the rotation of UIImageView using CAKeyframeAnimation

I'm using the following code to rotate an image infinitely, the rotation is clockwise but I also need it to reverse rotation to counter clockwise every 1-2 rotations and then back to clockwise, how to get this to work?

    /// Image Rotation - CAKeyframeAnimation
func rotate(imageView: UIImageView, rotationSpeed: Double) {

    let animation = CAKeyframeAnimation(keyPath: "transform.rotation.z")

    animation.duration = rotationSpeed
    animation.fillMode = CAMediaTimingFillMode.forwards
    animation.repeatCount = .infinity
    animation.values = [0, Double.pi/2, Double.pi, Double.pi*3/2, Double.pi*2]

    /// Percentage of each key frame
    let moments = [NSNumber(value: 0.0), NSNumber(value: 0.1),
                   NSNumber(value: 0.3), NSNumber(value: 0.8), NSNumber(value: 1.0)]
    animation.keyTimes = moments

    imageView.layer.add(animation, forKey: "rotate")
}

Upvotes: 5

Views: 441

Answers (2)

Frankenxtein
Frankenxtein

Reputation: 493

for counter clockwise rotation, you can do this:

self.imageView?.transform = CGAffineTransform(rotationAngle: -2*CGFloat.pi)

Upvotes: 0

Sagar Chauhan
Sagar Chauhan

Reputation: 5823

Set animation.autoreverses = true, will reverse an animation.

Upvotes: 1

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