fix: some apps have messy launch behavior

See discussion: https://github.com/lwouis/alt-tab-macos/issues/117#issuecomment-583868046

alt-tab-macos/api-wrappers/AXUIElement.swift

@@ -49,13 +49,15 @@ extension AXUIElement {
         return attribute(kAXSubroleAttribute, String.self)
     }
 
-    func subscribeWithRetry(_ axObserver: AXObserver, _ notification: String, _ pointer: UnsafeMutableRawPointer?) {
+    func subscribeWithRetry(_ axObserver: AXObserver, _ notification: String, _ pointer: UnsafeMutableRawPointer?, _ callback: (() -> Void)? = nil, _ previousResult: AXError? = nil) {
         let result = AXObserverAddNotification(axObserver, self, notification as CFString, pointer)
-        if result != .success && result != .notificationUnsupported && result != .notificationAlreadyRegistered {
-            DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(10), execute: {
-                self.subscribeWithRetry(axObserver, notification, pointer)
-            })
+        if result == .success || result == .notificationUnsupported || result == .notificationAlreadyRegistered {
+            callback?()
+            return
         }
+        DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(10), execute: {
+            self.subscribeWithRetry(axObserver, notification, pointer, callback, result)
+        })
     }
 
     private func attribute<T>(_ key: String, _ type: T.Type) -> T? {

alt-tab-macos/logic/Application.swift

@@ -4,6 +4,7 @@ class Application: NSObject {
     var runningApplication: NSRunningApplication
     var axUiElement: AXUIElement?
     var axObserver: AXObserver?
+    var isReallyFinishedLaunching = false
 
     init(_ runningApplication: NSRunningApplication) {
         self.runningApplication = runningApplication
@@ -22,13 +23,7 @@ class Application: NSObject {
     private func addAndObserveWindows() {
         axUiElement = AXUIElementCreateApplication(runningApplication.processIdentifier)
         AXObserverCreate(runningApplication.processIdentifier, axObserverCallback, &axObserver)
-        observeAllWindows()
-    }
-
-    private func observeAllWindows() {
-        let windows = getActualWindows()
-        debugPrint("Adding app: " + (runningApplication.bundleIdentifier ?? "nil"), windows.map { $0.title() })
-        addWindows(windows)
+        debugPrint("Adding app: " + (runningApplication.bundleIdentifier ?? "nil"))
         observeEvents()
     }
 
@@ -65,7 +60,14 @@ class Application: NSObject {
             kAXApplicationHiddenNotification,
             kAXApplicationShownNotification,
         ] {
-            axUiElement!.subscribeWithRetry(axObserver, notification, selfPointer)
+            axUiElement!.subscribeWithRetry(axObserver, notification, selfPointer, {
+                // some apps have `isFinishedLaunching == true` but are actually not finished, and will return .cannotComplete
+                // we consider them ready when the first subscription succeeds, and list their windows again at that point
+                if !self.isReallyFinishedLaunching {
+                    self.isReallyFinishedLaunching = true
+                    self.observeNewWindows()
+                }
+            })
         }
         CFRunLoopAddSource(CFRunLoopGetCurrent(), AXObserverGetRunLoopSource(axObserver), .defaultMode)
     }