CODEWITHSUNDEEP
iosswiftcabasicanimation
Adrian
Adrian

Reputation: 20068

CAAnimationDelegate delegates are never called

I made a simple progress line using two CAShapeLayer's. Animation works correctly but the CAAnimationDelegate animationDidStart and animationDidStop are never called.

Here is my code:

class ProgressBar: UIView, CAAnimationDelegate {

    var bottomProgressBar = CAShapeLayer()
    var topProgressBar = CAShapeLayer()
    let animation = CABasicAnimation(keyPath: "strokeEnd")

    override init(frame: CGRect) {
        super.init(frame: frame)
        configure()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        configure()
    }

    func configure() {
        animation.delegate = self

        // setup the two layers
    }

    func animate(toValue: Double) {

        animation.duration = 1.0
        animation.fromValue = 0
        animation.toValue = toValue

        topProgressBar.strokeEnd = CGFloat(toValue)
        topProgressBar.animation(forKey: "animate")
    }

    func animationDidStart(_ anim: CAAnimation) {
        print("start")
    }

    func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
        print("stop")
    }
}

animate method is called multiple times with values ranging from 0 to 1.

Does anyone know why these delegates are never called ?

Upvotes: 0

Views: 1114

Answers (1)

Josh Homann
Josh Homann

Reputation: 16327

EDIT: add correct solution with links per comment below

You are calling topProgressBar.animation(forKey: "animate") which actually returns the animation; it doesn't start it. You should call layer.add(animation, forKey:) instead

Upvotes: 1

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