Mac Catalyst applicationShouldTerminateAfterLastWindowClosed

[tommycarpi]

Hi guys,
I've got another question, with Dynamic on Mac Catalyst is it possible to include applicationShouldTerminateAfterLastWindowClosed in the AppDelegate?

#if targetEnvironment(macCatalyst)
func applicationShouldTerminateAfterLastWindowClosed(_ sender: NSApplication) -> Bool {
// ...
}
#endif

Thanks in advance

[polymerchm]

Not clear to me that method is exposed in ApplicationDelegate. Only in NSApplicationDelegate. Likely, you will need to create an observer for the notification, if you can figure out what the notification string is.

I leave this to Mhd.

[Martin Man]

I have tried to set my custom NSApplicationDelegate using the loaded AppKit bundle trick to achieve this, but Catalyst did override/ignore my custom delegate, and it did not work. I'm also interested how to make this work.

[tommycarpi]

I managed to subscribe to some notifications in order to be alerted upon resignation and activation.
I couldn't solve the ShouldTerminateAfterLastWindowClosed yet, but that's a start.

Here is the code for future reference:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    #if targetEnvironment(macCatalyst)
    NotificationCenter.default.addObserver(self, selector: #selector(resignActive), name: NSNotification.Name("NSApplicationDidResignActiveNotification"),object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(becomingActive), name: NSNotification.Name("NSApplicationDidBecomeActiveNotification"),object: nil)
    #endif
}

@objc func resignActive() {
    // ... your code
  }
  
@objc func becomingActive() {
    // ... your code
}

[Martin Man]

More debugging here: If you hook into the app/scene lifecycle, you will see that NSApplication.shared.delegate is actually nil until first scene completes loading. Only after that it makes sense to actually swap the NSApplicationDelegate class.

However, Mac Catalyst app actually expects the NSApplicationDelegate to be of class UINSApplicationDelegate, whose dump can be found for example here: https://github.com/w0lfschild/macOS_headers/blob/master/macOS/PrivateFrameworks/UIKitMacHelper/61000/UINSApplicationDelegate.h and that delegate implements couple of undocumented methods and variables that you need to cope with.

No success so far on my side.