Restore state after application enters background.

[iambenmitchell]

Wherever someone leaves my app and lets it go into the background, when they then later open the app, the gradient is no longer cycling.

Is there away to restore the state the gradient was in before being sent to background?

thank you.

I think I should be able to do it with func applicationDidBecomeActive(_ application: UIApplication) { but I don't know how

[iambenmitchell]

override func viewDidLoad() {
    super.viewDidLoad()
    gradient()
    NotificationCenter.default.addObserver(self, selector: #selector(willEnterForeground), name: UIApplication.willEnterForegroundNotification
        , object: nil)

}

@objc func willEnterForeground() {
    print("test")
    gradient()
}

func gradient(){
    let pastelView = PastelView(frame: view.bounds)
    
    // Custom Direction
    pastelView.startPastelPoint = .bottomLeft
    pastelView.endPastelPoint = .topRight
    
    // Custom Duration
    pastelView.animationDuration = 1.5
    
    // Custom Color
    pastelView.setColors([UIColor(red: 156/255, green: 39/255, blue: 176/255, alpha: 1.0),
                          UIColor(red: 255/255, green: 64/255, blue: 129/255, alpha: 1.0),
                          UIColor(red: 123/255, green: 31/255, blue: 162/255, alpha: 1.0),
                          UIColor(red: 32/255, green: 76/255, blue: 255/255, alpha: 1.0),
                          UIColor(red: 32/255, green: 158/255, blue: 255/255, alpha: 1.0),
                          UIColor(red: 90/255, green: 120/255, blue: 127/255, alpha: 1.0),
                          UIColor(red: 58/255, green: 255/255, blue: 217/255, alpha: 1.0)])
    
    
    pastelView.startAnimation()
    view.insertSubview(pastelView, at: 0)
    print("Test1")
}

"Test" and "Test1" are printed to the console yet the application refuses to resume the gradient

[dannmat]

Also have this issue

[kaseyb002]

@MrBenFTW
You're inserting a new pastelView behind the ones that are already in there each time you call gradient().

view.insertSubview(pastelView, at: 0)

I'd just keep a reference to pastelView and reinit each time. Add it to the main view only once.

// View Controller property
private lazy var pastelView = PastelView(frame: view.bounds)

func restartPastel() {
    pastelView = PastelView(frame: view.bounds)
    pastelView.startAnimation()
}

@objc func willEnterForeground() {
    restartPastel()
}