UIButton Heartbeat Animation - swift

Question

I've created a heart beat animation for a UIButton. However, there is no way to stop this animation as it's an endless code loop. After tinkering with numerous UIView animation code blocks I've been unable to get UIViewAnimationOptions.Repeat to produce what I need. If I could do that I could simply button.layer.removeAllAnimations() to remove the animations. What is a way to write this that allows for removal of the animation? I'm thinking a timer possibly but that could be kind of messy with multiple animations going on.
func heartBeatAnimation(button: UIButton) {
button.userInteractionEnabled = true
button.enabled = true
func animation1() {
UIView.animateWithDuration(0.5, delay: 0.0, options: [], animations: { () -> Void in
button.transform = CGAffineTransformMakeScale(2.0, 2.0)
button.transform = CGAffineTransformIdentity
}, completion: nil)
UIView.animateWithDuration(0.5, delay: 0.5, options: [], animations: { () -> Void in
button.transform = CGAffineTransformMakeScale(2.0, 2.0)
button.transform = CGAffineTransformIdentity
}) { (Bool) -> Void in
delay(2.0, closure: { () -> () in
animation2()
})
}
}
func animation2() {
UIView.animateWithDuration(0.5, delay: 0.0, options: [], animations: { () -> Void in
button.transform = CGAffineTransformMakeScale(2.0, 2.0)
button.transform = CGAffineTransformIdentity
}, completion: nil)
UIView.animateWithDuration(0.5, delay: 0.5, options: [], animations: { () -> Void in
button.transform = CGAffineTransformMakeScale(2.0, 2.0)
button.transform = CGAffineTransformIdentity
}) { (Bool) -> Void in
delay(2.0, closure: { () -> () in
animation1()
})
}
}
animation1()
}

Answer 1

This works perfectly. The damping and spring need to be tweaked a little bit but this solves the problem. removeAllAnimations() clears the animation and returns the button to it's normal state.
button.userInteractionEnabled = true
button.enabled = true
let pulse1 = CASpringAnimation(keyPath: "transform.scale")
pulse1.duration = 0.6
pulse1.fromValue = 1.0
pulse1.toValue = 1.12
pulse1.autoreverses = true
pulse1.repeatCount = 1
pulse1.initialVelocity = 0.5
pulse1.damping = 0.8
let animationGroup = CAAnimationGroup()
animationGroup.duration = 2.7
animationGroup.repeatCount = 1000
animationGroup.animations = [pulse1]
button.layer.addAnimation(animationGroup, forKey: "pulse")
This post was very helpful: CAKeyframeAnimation delay before repeating

Answer 2

Swift 5 code, works without the pause between pulses:
let pulse = CASpringAnimation(keyPath: "transform.scale")
pulse.duration = 0.4
pulse.fromValue = 1.0
pulse.toValue = 1.12
pulse.autoreverses = true
pulse.repeatCount = .infinity
pulse.initialVelocity = 0.5
pulse.damping = 0.8
switchButton.layer.add(pulse, forKey: nil)

Answer 3

I created something like this:
let animation = CAKeyframeAnimation(keyPath: "transform.scale")
animation.values = [1.0, 1.2, 1.0]
animation.keyTimes = [0, 0.5, 1]
animation.duration = 1.0
animation.repeatCount = Float.infinity
layer.add(animation, forKey: "pulse")

Answer 4

On your original question you mentioned that you want the animation to stop on command. I assume you would like it to start on command too. This solution will do both and it is quite simple.
func cutAnim(){
for view in animating {
///I use a UIView because I wanted the container of my button to be animated. UIButton will work just fine too.
(view.value as? UIView)?.layer.removeAllAnimations()
}
}
func pulse(button: UIButton, name: String){
///Here I capture that container
let container = button.superview?.superview
///Add to Dictionary
animating[name] = container
cutAnim()
UIView.animate(withDuration: 1, delay: 0.0, options:[UIViewAnimationOptions.repeat, UIViewAnimationOptions.autoreverse, .allowUserInteraction], animations: {
container?.transform = CGAffineTransform(scaleX: 1.15, y: 1.15)
///if you stop the animation half way it completes anyways so I want the container to go back to its original size
container?.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
}, completion: nil)
}
Call cutAnim() anywhere to stop an animation, inside a timer if you want.
To start the animation use a regular button action
#IBAction func buttonWasTappedAction(_ sender: Any) {
pulse(button: sender as! UIButton, name: "nameForDictionary")
}
Hope this helps.