Invoke repeatable task when viewDidApper - swift

Question

I might be heading totally wrong direction, but what I'm trying to achieve is to load some view first and invoke some methods that will be running afterwards infinitely, while at the same time giving the User the possibility to interact with this view.
My first guess was to use viewDidApper with UIView.animate, as per below;
class MainView: UIView {
...
func animateTheme() {
//want this to print out infinitely
print("Test")
}
}
class ViewController: UIViewController {
#IBOutlet weak var mainView: MainView!
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
UIView.animate(withDuration: 1.0, delay: 0.0, options: .repeat, animations: {
self.mainView.animateTheme()
}, completion: nil)
}
}
The case is that I can only see a single "Test" printed out but this has to be invoked infinitely. Also, as I mentioned the User needs to have the possibility to interact with the view once everything is loaded.
Thanks a lot for any of your help.

Answer 1

ViewDidAppear will indeed be called latest when the view is loaded, but I don´t think the user can or will have the time to interact before it´s loaded.
If you want to load animations after everything is loaded you could create a timer and wait x seconds before you do that. Below example will be called 10 seconds after initiation.
var timer = Timer()
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
timer = Timer.scheduledTimer(timeInterval: 10.0, target: self, selector: #selector(animateSomething), userInfo: nil, repeats: false)
}
func animateSomething() {
// Animate here
}
Update
To make an infinite loop you can use the following snippet:
UIView.animate(withDuration: 5.0, delay: 0, options: [.repeat, .autoreverse], animations: {
self.view.frame = CGRect(x: 100, y: 200, width: 200, height: 200)
}, completion: nil)

Answer 2

I've done something very similar on one of my ViewControllers that loads a UIWebView. While the webpage is loading I show a UILabel with text "Loading" and every 1.5 seconds I add a period to the end of the text. I think the approach you describe above and mine shown below have the same effect and neither would be considered an infinite loop.
private func showLoadingMessage(){
let label = loadingLabel ?? UILabel(frame: CGRect.zero)
label.text = "Loading"
view.addSubview(label)
loadingLabel = label
addEllipsis()
}
private func addEllipsis() {
if webpageHasLoaded { return }
guard let labelText = loadingLabel?.text else {
return
}
DispatchQueue.main.asyncAfter(deadline: .now() + 1.5) {
self.loadingLabel?.text = labelText + "."
self.addEllipsis()
}
}