Loading an “overlay” when running long tasks in iO

Question

What is example for loading overlay in Swift IOS application when do a long tasks. Example for loading data from remote server. I googled but not found any answer.

Updated:

Thanks for @Sebastian Dressler this is simple way. I updated my code and it run cool

public class LoadingOverlay{

var overlayView = UIView()
var activityIndicator = UIActivityIndicatorView()

class var shared: LoadingOverlay {
    struct Static {
        static let instance: LoadingOverlay = LoadingOverlay()
    }
    return Static.instance
}

    public func showOverlay(view: UIView) {

        overlayView.frame = CGRectMake(0, 0, 80, 80)
        overlayView.center = view.center
        overlayView.backgroundColor = UIColor(hex: 0x444444, alpha: 0.7)
        overlayView.clipsToBounds = true
        overlayView.layer.cornerRadius = 10

        activityIndicator.frame = CGRectMake(0, 0, 40, 40)
        activityIndicator.activityIndicatorViewStyle = .WhiteLarge
        activityIndicator.center = CGPointMake(overlayView.bounds.width / 2, overlayView.bounds.height / 2)

        overlayView.addSubview(activityIndicator)
        view.addSubview(overlayView)

        activityIndicator.startAnimating()
    }

    public func hideOverlayView() {
        activityIndicator.stopAnimating()
        overlayView.removeFromSuperview()
    }
}

let using:

LoadingOverlay.shared.showOverlay(self.view)
//To to long tasks
LoadingOverlay.shared.hideOverlayView()

Answer 1

Use ATKit.

Refer: https://aurvan.github.io/atkit-ios-release/index.html

ATProgressOverlay Class https://aurvan.github.io/atkit-ios-release/helpbook/Classes/ATProgressOverlay.html

Code:

import ATKit

ATProgressOverlay.sharedInstance.show() // Does not show network activity indicator on status bar.

ATProgressOverlay.sharedInstance.show(isNetworkActivity: true) // Shows network activity indicator on status bar.

Screenshot:

Answer 2

To add on to the answers given, you might run into issues if you are attempting to run the code sometimes. Personally, there was an occasion where showOverlay was not being properly called (because I was trying to segue into a scene, then immediately call this function during viewDidLoad).

If you run into an issue similar to mine, there is one fix to the code and a change in approach I recommend.

FIX: Place both blocks of code as closures to a dispatch_async call, like so:

dispatch_async(dispatch_get_main_queue(),
 { //code });

APPROACH: When calling your code, do a dispatch_after call onto the main queue to delay the call by a few milliseconds.

The reasoning? You're simply asking the UI to do too much during viewDidLoad.

If this appendix to the solution helped, I'd be glad.

-Joel Long

P.S. Solution worked for XCode v6.3.2

Answer 3

Swift 3.

I used @Lucho's code in his answer below and I changed the overlay background color to clear and added a spinner color.

public class LoadingOverlay {

    var overlayView : UIView!
    var activityIndicator : UIActivityIndicatorView!

    class var shared: LoadingOverlay {
        struct Static {
            static let instance: LoadingOverlay = LoadingOverlay()
        }
        return Static.instance
    }

    init(){
        self.overlayView = UIView()
        self.activityIndicator = UIActivityIndicatorView()

        overlayView.frame = CGRect(0, 0, 80, 80)
        overlayView.backgroundColor = .clear
        overlayView.clipsToBounds = true
        overlayView.layer.cornerRadius = 10
        overlayView.layer.zPosition = 1

        activityIndicator.frame = CGRect(0, 0, 40, 40)
        activityIndicator.center = CGPoint(overlayView.bounds.width / 2, overlayView.bounds.height / 2)
        activityIndicator.activityIndicatorViewStyle = .whiteLarge
        activityIndicator.color = .gray
        overlayView.addSubview(activityIndicator)
    }

    public func showOverlay(view: UIView) {
        overlayView.center = view.center
        view.addSubview(overlayView)
        activityIndicator.startAnimating()
    }

    public func hideOverlayView() {
        activityIndicator.stopAnimating()
        overlayView.removeFromSuperview()
    }
}