how can I implement a singleton spinner (activityindicator)? - swift

Question

i want to implement a singleton spinner, because any app that has a api needs a spinner. well I can code a spinner custom, but my problem is that I should code the next line ever if I want to show it.
let rosetaGIF = UIImage(named: "wheel.png")
let ind = MyIndicator(frame: CGRect(x: 0, y: 0, width: (rosetaGIF?.size.width)!/2, height: (rosetaGIF?.size.height)!/2), image: rosetaGIF!)
view.addSubview(ind)
view.alpha = 0.5
ind.startAnimating()
that's not good, because I must put this lines every time that I want to show the spinner, well, my spinner class is the next. I'm using swift 4.2
import UIKit
class MyIndicator: UIActivityIndicatorView {
let loadingView = UIView(frame: (UIApplication.shared.delegate?.window??.bounds)!)
let imageView = UIImageView()
let sizeView = UIViewController()
init(frame: CGRect, image: UIImage) {
super.init(frame: frame)
imageView.frame = bounds
imageView.image = image
imageView.contentMode = .scaleAspectFit
imageView.center = CGPoint(x: sizeView.view.frame.width/2, y: sizeView.view.frame.height/2)
imageView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
addSubview(imageView)
}
required init(coder: NSCoder) {
fatalError()
}
override func startAnimating()
{
isHidden = false
rotate()
}
override func stopAnimating()
{
isHidden = true
removeRotation()
}
private func rotate() {
let rotation : CABasicAnimation = CABasicAnimation(keyPath: "transform.rotation.z")
rotation.toValue = NSNumber(value: Double.pi * 1)
rotation.duration = 1
rotation.isCumulative = true
rotation.repeatCount = Float.greatestFiniteMagnitude
self.imageView.layer.add(rotation, forKey: "rotationAnimation")
}
private func removeRotation() {
self.imageView.layer.removeAnimation(forKey: "rotationAnimation")
}
}
what should I do for that the spinner will be singleton?
thanks

Answer 1

I suggest you create a util class and make that class Singleton.
import UIKit
class Util {
static let shared = Util()
private init(){}
var loader: MyIndicator?
func showLoader(view: UIView){
hideLoader()
let rosetaGIF = UIImage(named: "wheel.png")
loader = MyIndicator(frame: CGRect(x: 0, y: 0, width: (rosetaGIF?.size.width)!/2, height: (rosetaGIF?.size.height)!/2), image: rosetaGIF!)
view.addSubview(loader!)
view.alpha = 0.5
loader?.startAnimating()
}
func hideLoader(){
loader?.stopAnimating()
loader?.removeFromSuperview()
}
}
How to use this class
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
Util.shared.showLoader(view: view) // for showing the loader
Util.shared.hideLoader() // for hiding the loader
}
}

Answer 2

Create a Base Controller with your spinner, then inherit other Controllers from you Base Controller and show the spinner whenever you want.
class BaseViewController: UIViewController {
var activityIndicator: UIActivityIndicatorView!
override func viewDidLoad() {
super.viewDidLoad()
activityIndicator = UIActivityIndicatorView(frame: CGRect(x: (UIScreen.main.bounds.width-40)/2, y: (UIScreen.main.bounds.height-40)/2, width: 40, height: 40))
activityIndicator.transform = CGAffineTransform(scaleX: 2, y: 2)
activityIndicator.color = .darkGray
view.addSubview(activityIndicator)
}
}
class ViewController: BaseViewController {
override func viewDidLoad() {
super.viewDidLoad()
activityIndicator.startAnimating() // you can show the spinner wherever you want.
}
}
hope this will help to you.