Fix Mission Control detection; Cleanup WKFullScreenWindowController hack

DuckDuckGo/Common/Extensions/NSWorkspaceExtension.swift

@@ -35,27 +35,25 @@ extension NSWorkspace {
             return false
         }
 
-        let allScreenSizes = NSScreen.screens.map(\.frame.size)
-
         // Here‘s the trick: normally the Dock App only displays full-screen overlay windows drawing the Dock.
         // When the Mission Control is activated, the Dock presents multiple window tiles for each visible window
         // so here we filter out all the screen-sized windows and if the resulting list is not empty it may
         // mean that Mission Control is active.
-        let missionControlWindows = visibleWindows.filter { window in
-            windowName(window) == "Dock" && !allScreenSizes.contains(windowSize(window))
+        let dockAppWindows = visibleWindows.filter { window in
+            window.ownerName == "Dock"
         }
-
-        func windowName(_ dict: [CFString: Any]) -> String? {
-            dict[kCGWindowOwnerName] as? String
+        // filter out wallpaper windows
+        var missionControlWindows = dockAppWindows.filter { window in
+            window.name?.hasPrefix("Wallpaper") != true
         }
-        func windowSize(_ dict: [CFString: Any]) -> NSSize {
-            guard let bounds = dict[kCGWindowBounds] as? [String: NSNumber],
-                  let width = bounds["Width"]?.intValue,
-                  let height = bounds["Height"]?.intValue else { return .zero }
-            return NSSize(width: width, height: height)
+        // filter out the Dock drawing windows
+        for screen in NSScreen.screens {
+            if let idx = missionControlWindows.firstIndex(where: { window in window.size == screen.frame.size }) {
+                missionControlWindows.remove(at: idx)
+            }
         }
 
-        return missionControlWindows.count > allScreenSizes.count
+        return missionControlWindows.count > 0
     }
 
     @available(macOS, obsoleted: 14.0, message: "This needs to be removed as it‘s no longer necessary.")
@@ -79,3 +77,22 @@ extension NSWorkspace.OpenConfiguration {
     }
 
 }
+
+private extension [CFString: Any] {
+
+    var name: String? {
+        self[kCGWindowName] as? String
+    }
+
+    var ownerName: String? {
+        self[kCGWindowOwnerName] as? String
+    }
+
+    var size: NSSize {
+        guard let bounds = self[kCGWindowBounds] as? [String: NSNumber],
+              let width = bounds["Width"]?.intValue,
+              let height = bounds["Height"]?.intValue else { return .zero }
+        return NSSize(width: width, height: height)
+    }
+
+}

DuckDuckGo/Tab/Model/Tab.swift

@@ -333,36 +333,18 @@ protocol NewWindowPolicyDecisionMaker {
     }
 
     deinit {
-        cleanUpBeforeClosing(onDeinit: true, webView: webView, userContentController: userContentController)
-    }
-
-    func cleanUpBeforeClosing() {
-        cleanUpBeforeClosing(onDeinit: false, webView: webView, userContentController: userContentController)
-    }
-
-    @MainActor(unsafe)
-    private func cleanUpBeforeClosing(onDeinit: Bool, webView: WebView, userContentController: UserContentController?) {
-        let job = { [webView, userContentController] in
+        DispatchQueue.main.asyncOrNow { [webView, userContentController] in
+            // WebKit objects must be deallocated on the main thread
             webView.stopAllMedia(shouldStopLoading: true)
 
             userContentController?.cleanUpBeforeClosing()
+
 #if DEBUG
             if case .normal = NSApp.runType {
                 webView.assertObjectDeallocated(after: 4.0)
             }
 #endif
         }
-#if DEBUG
-        if !onDeinit, case .normal = NSApp.runType {
-            // Tab should be deallocated shortly after burning
-            self.assertObjectDeallocated(after: 4.0)
-        }
-#endif
-        guard Thread.isMainThread else {
-            DispatchQueue.main.async { job() }
-            return
-        }
-        job()
     }
 
     func stopAllMediaAndLoading() {

DuckDuckGo/Tab/View/WebViewContainerView.swift

@@ -51,7 +51,6 @@ final class WebViewContainerView: NSView {
     }
 
     private var blurViewIsHiddenCancellable: AnyCancellable?
-    private var fullScreenWindowWillCloseCancellable: AnyCancellable?
     private var cancellables = Set<AnyCancellable>()
 
     override func didAddSubview(_ subview: NSView) {
@@ -122,43 +121,20 @@ final class WebViewContainerView: NSView {
     // (three-fingers-up swipe)
     // see https://app.asana.com/0/1177771139624306/1204370242122745/f
     private func observeFullScreenWindowWillExitFullScreen(_ fullScreenWindow: NSWindow) {
-        NotificationCenter.default.publisher(for: NSWindow.willExitFullScreenNotification, object: fullScreenWindow)
-            .sink { [weak self] _ in
-                guard let self else { return }
-                self.cancellables.removeAll()
-
-                if NSWorkspace.isMissionControlActive() {
-                    // closeAllMediaPresentations causes all Full Screen windows to be closed and removed from their WebViews
-                    // (and reinstantiated the next time Full Screen is requested)
-                    // this would slightly break UX in case multiple Full Screen windows are open but it fixes the bug
-                    if #available(macOS 12.0, *) {
+        if #available(macOS 12.0, *) { // works fine on Big Sur
+            NotificationCenter.default.publisher(for: NSWindow.willExitFullScreenNotification, object: fullScreenWindow)
+                .sink { [weak self] _ in
+                    guard let self else { return }
+                    self.cancellables.removeAll()
+
+                    if NSWorkspace.isMissionControlActive() {
+                        // closeAllMediaPresentations causes all Full Screen windows to be closed and removed from their WebViews
+                        // (and reinstantiated the next time Full Screen is requested)
                         webView.closeAllMediaPresentations {}
-                    } else {
-                        webView.closeAllMediaPresentations()
-                    }
-
-                }
-            }
-            .store(in: &cancellables)
-
-        // https://app.asana.com/0/72649045549333/1206959015087322/f
-        if #unavailable(macOS 14.4) {
-            fullScreenWindowWillCloseCancellable = NotificationCenter.default.publisher(for: NSWindow.willCloseNotification, object: fullScreenWindow)
-                .sink { [weak self] notification in
-                    self?.fullScreenWindowWillCloseCancellable = nil
-                    let fullScreenWindowController = (notification.object as? NSWindow)?.windowController
-                    DispatchQueue.main.async { [weak fullScreenWindowController] in
-                        guard let fullScreenWindowController else { return }
-                        // just in case.
-                        // if WKFullScreenWindowController receives `close()` the next time it‘s open it will crash because its _webView is nil
-                        // https://errors.duckduckgo.com/organizations/ddg/issues/3411/?project=6&referrer=release-issue-stream
-                        NSException.try {
-                            fullScreenWindowController.setValue(NSView(), forKeyPath: #keyPath(webView))
-                        }
                     }
                 }
+                .store(in: &cancellables)
         }
-
     }
 
     override func removeFromSuperview() {