macOS/SwiftUI onDisappear not called when window is closed

Question

I'm trying to simply call a function in my AppDelegate when the user closes the app's preferences, which is the ContentView below.

A breakpoint in onDisappear never hits for some reason. I'd love some help understanding why that is.

struct ContentView: View {
    
    @EnvironmentObject var state: AppState
    
    var body: some View {
        Text("Hi there")
           .onDisappear {
                // Never gets in here, breakpoint never hits
                let appDelegate = NSApplication.shared.delegate as! AppDelegate
                appDelegate.hideIcon()
           }

    }

In my AppDelegate:

func hideIcon() {
    NSApp.setActivationPolicy(.accessory)
}

How content view is initiated:

    @objc func preferences() {

        let contentView = ContentView().environmentObject(state)

        // Create the window and set the content view.
        window = NSWindow(
            contentRect: NSRect(x: 0, y: 0, width: 480, height: 300),
            styleMask: [.titled, .closable],
            backing: .buffered, defer: false)
        window.isReleasedWhenClosed = false
        window.center()
        window.setFrameAutosaveName("Arch OS System Preferences")
        window.contentView = NSHostingView(rootView: contentView)
        window.makeKeyAndOrderFront(nil)
    
        NSApp.setActivationPolicy(.regular)
        
        NSRunningApplication.current.activate(options: [.activateIgnoringOtherApps, .activateAllWindows])
    }

Thanks!

question from:https://stackoverflow.com/questions/65617708/macos-swiftui-ondisappear-not-called-when-window-is-closed

Answer 1

Waitting for answers