How do I delete CABasicAnimation and then restart it in Swift? - ios

Question

I am building an app that will show an animation when a certain function is running and remove it once the next function runs. However I need it to restart when it loops back.
I have been able to remove it from the view with
isHidden = true
But if I rely on this to bring it back it layers a second animation over the first when it runs again and I unhide it.
I was also able to use .removeFromSuperView()
to make it disappear but I can't figure out how to bring it back after that.
Here is the relevant code:
class ViewController: UIViewController {
// some code
let dots = UIImageView()
override func viewDidLoad() {
super.viewDidLoad()
// some code
dots.translatesAutoresizingMaskIntoConstraints = false
dots.backgroundColor = .red
dots.center = self.view.center
view.addSubview(dots)
// Some Auto Layout code
}
func showAnimatingDotsInImageView(_ isOn: Bool) {
let lay = CAReplicatorLayer()
if isOn == true {
lay.frame = CGRect(x: -55, y: 0, width: 30, height: 14) //yPos == 12
let circle = CALayer()
circle.frame = CGRect(x: 10, y: 10, width: 10, height: 10)
circle.cornerRadius = circle.frame.width / 2
circle.backgroundColor = rocketDark.cgColor//lightGray.cgColor //UIColor.black.cgColor
lay.addSublayer(circle)
lay.instanceCount = 5
lay.instanceTransform = CATransform3DMakeTranslation(20, 0, 0)
let anim = CABasicAnimation(keyPath: #keyPath(CALayer.opacity))
anim.fromValue = 0.0
anim.toValue = 1.0
anim.duration = 2
anim.repeatCount = .infinity
circle.add(anim, forKey: "animation")
lay.instanceDelay = anim.duration / Double(lay.instanceCount)
dots.layer.addSublayer(lay)
} else if isOn == false {
//lay.removeFromSuperlayer()
//lay.removeAllAnimations()
dots.removeFromSuperview()
//dots.stopAnimating()
}
}
As you can probably tell I was attempting to hack together a way to write howAnimatingDotsInImageView(false) to remove it and howAnimatingDotsInImageView(true) to restart it.

Answer 1

I didn't compile this code, but I think using this approach you can remove your animation
class ViewController: UIViewController {
// some code
let dots = UIImageView()
let circleLayer: CAlayer? // Save circle layer property
override func viewDidLoad() {
super.viewDidLoad()
// some code
dots.translatesAutoresizingMaskIntoConstraints = false
dots.backgroundColor = .red
dots.center = self.view.center
view.addSubview(dots)
// Some Auto Layout code
}
func showAnimatingDotsInImageView(_ isOn: Bool) {
let lay = CAReplicatorLayer()
if isOn == true {
lay.frame = CGRect(x: -55, y: 0, width: 30, height: 14) //yPos == 12
circleLayer = CALayer()
circleLayer?.frame = CGRect(x: 10, y: 10, width: 10, height: 10)
circleLayer?.cornerRadius = circle?.frame.width / 2 ?? .zero
circleLayer?.backgroundColor = rocketDark.cgColor//lightGray.cgColor //UIColor.black.cgColor
circleLayer.map { lay.addSublayer($0) }
lay.instanceCount = 5
lay.instanceTransform = CATransform3DMakeTranslation(20, 0, 0)
let anim = CABasicAnimation(keyPath: #keyPath(CALayer.opacity))
anim.fromValue = 0.0
anim.toValue = 1.0
anim.duration = 2
anim.repeatCount = .infinity
circleLayer?.add(anim, forKey: "animation")
lay.instanceDelay = anim.duration / Double(lay.instanceCount)
dots.layer.addSublayer(lay)
} else if isOn == false {
circleLayer?.removeAnimation(forKey: "animation")
}
}