How to animate a constantly flickering light in iOS? - ios

Question

I'm trying to build an iOS app with a neon light that flickers randomly and constantly like a real one would.
I'm not totally sure how to get the animation to repeat constantly, and I'm not sure how to get it to just run automatically and forever. I put this in the viewDidLoad, but I'm not sure if that's really the best place to put it?
UIImageView.animate(withDuration: 0.05, delay: 5.0, options: .repeat, animations: {
UIImageView.animate(withDuration: 0.05, delay: 2.0, animations: {
self.Aletter.alpha = 0.2
}) { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 1.0
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 2.0, animations: {
self.Aletter.alpha = 0.6
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 1.0
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 0.6
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 1.0
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 0.6
}, completion: { (_) in
UIImageView.animate(withDuration: 0.05, delay: 0.0, animations: {
self.Aletter.alpha = 1.0
}, completion: { (_) in
})
})
})
})
})
})
})
}
})
This code will run my series of flickers, but only once. I need it to go continuously.

Answer 1

As suggested by Matt in the comments section, you can use something like this:
private func flicker() { [weak self] in
UIView.animate(withDuration: 0.05, animations: {
self?.Aletter.alpha = CGFloat.random(in: 0.1...1.0)
}) { _ in
// When this round of animations completes call the same method again to start the animations again with a new random value for alpha.
self?.flicker()
}
}
And just call flicker() in your viewDidLoad(). flicker method starts an animation with a random alpha value for Aletter view, and when this animation completes it calls itself again.
As a side note, use small first letters for your variables, Aletter should be aletter or maybe aLetter based on the context.