fix: closing a window would remove the thumbnail (closes #5324)

src/api-wrappers/AXUIElement.swift

@@ -33,14 +33,15 @@ extension AXUIElement {
     }
 
     /// if the window server is busy, it may not reply to AX calls. We retry right before the call times-out and returns a bogus value
-    static func retryAxCallUntilTimeout(file: String = #file, function: String = #function, line: Int = #line, context: String = "", after: DispatchTime? = nil, pid: pid_t? = nil, wid: CGWindowID? = nil, retriesQueue: Bool = false, startTimeInNanoseconds: UInt64 = DispatchTime.now().uptimeNanoseconds, callType: AXCallType, block: @escaping () throws -> Void) {
-        let closure = { retryAxCallUntilTimeout_(file: file, function: function, line: line, context: context, after: after, pid: pid, wid: wid, retriesQueue: retriesQueue, startTimeInNanoseconds: startTimeInNanoseconds, callType: callType, block: block) }
+    static func retryAxCallUntilTimeout(file: String = #file, function: String = #function, line: Int = #line, context: String = "", after: DispatchTime? = nil, pid: pid_t? = nil, wid: CGWindowID? = nil, retriesQueue: Bool = false, startTimeInNanoseconds: UInt64 = DispatchTime.now().uptimeNanoseconds, isWindowDestroyedEvent: Bool = false, callType: AXCallType, block: @escaping () throws -> Void) {
+        let closure = { retryAxCallUntilTimeout_(file: file, function: function, line: line, context: context, after: after, pid: pid, wid: wid, retriesQueue: retriesQueue, startTimeInNanoseconds: startTimeInNanoseconds, isWindowDestroyedEvent: isWindowDestroyedEvent, callType: callType, block: block) }
         let queue = (callType == .updateAppWindows ? BackgroundWork.axCallsManualDiscoveryQueue
             : (retriesQueue ? BackgroundWork.axCallsRetriesQueue
                 : BackgroundWork.axCallsFirstAttemptQueue))!
         if callType == .updateWindowFromAxEvent || callType == .updateWindowFromManualDiscovery {
             guard let wid else { Logger.error { (callType, context, file, function, line) }; return }
-            if throttleOrProceed(key: "\(callType.rawValue)-wid-\(wid)", queue: queue, closure: closure) { return }
+            // we don't throttle windowDestroyedEvent as these are key events to process
+            if !isWindowDestroyedEvent && throttleOrProceed(key: "\(callType.rawValue)-wid-\(wid)", queue: queue, closure: closure) { return }
         }
         if callType == .updateApp || callType == .updateAppWindows || callType == .updateAppFocusedWindow {
             guard let pid else { Logger.error { (callType, context, file, function, line) }; return }
@@ -53,7 +54,7 @@ extension AXUIElement {
         }
     }
 
-    private static func retryAxCallUntilTimeout_(file: String, function: String, line: Int, context: String, after: DispatchTime?, pid: pid_t?, wid: CGWindowID?, retriesQueue: Bool, startTimeInNanoseconds: UInt64, callType: AXCallType, block: @escaping () throws -> Void) {
+    private static func retryAxCallUntilTimeout_(file: String, function: String, line: Int, context: String, after: DispatchTime?, pid: pid_t?, wid: CGWindowID?, retriesQueue: Bool, startTimeInNanoseconds: UInt64, isWindowDestroyedEvent: Bool, callType: AXCallType, block: @escaping () throws -> Void) {
         // attempt the AX call
         if (try? block()) != nil {
             return
@@ -66,7 +67,7 @@ extension AXUIElement {
         }
         // retry
         Logger.debug { "(pid:\(pid) wid:\(wid)) \(logFromContext(file, function, line, context, callType))" }
-        retryAxCallUntilTimeout(file: file, function: function, line: line, context: context, after: .now() + humanPerceptionDelay, pid: pid, wid: wid, retriesQueue: true, startTimeInNanoseconds: startTimeInNanoseconds, callType: callType, block: block)
+        retryAxCallUntilTimeout(file: file, function: function, line: line, context: context, after: .now() + humanPerceptionDelay, pid: pid, wid: wid, retriesQueue: true, startTimeInNanoseconds: startTimeInNanoseconds, isWindowDestroyedEvent: isWindowDestroyedEvent, callType: callType, block: block)
     }
 
     private static func logFromContext(_ file: String, _ function: String, _ line: Int, _ context: String, _ callType: AXCallType) -> String {
@@ -82,7 +83,6 @@ extension AXUIElement {
                 if elapsed < windowNs {
                     if !state.tailScheduled {
                         map[key] = ThrottleState(time: state.time, tailScheduled: true)
-
                         let remaining = windowNs - elapsed
                         queue.addOperationAfter(deadline: .now() + .nanoseconds(Int(remaining))) {
                             throttleMap.withLock { $0[key] = nil }

src/logic/events/AccessibilityEvents.swift

@@ -19,8 +19,8 @@ class AccessibilityEvents {
                 try handleEventApp(type, pid, element)
             }
         } else {
-            let wid = try element.cgWindowId()
-            AXUIElement.retryAxCallUntilTimeout(context: "(pid:\(pid))", pid: pid, wid: wid, callType: .updateWindowFromAxEvent) {
+            let wid = (try? element.cgWindowId()) ?? 0
+            AXUIElement.retryAxCallUntilTimeout(context: "(pid:\(pid))", pid: pid, wid: wid, isWindowDestroyedEvent: type == kAXUIElementDestroyedNotification, callType: .updateWindowFromAxEvent) {
                 try handleEventWindow(type, wid, pid, element)
             }
         }
@@ -76,15 +76,18 @@ class AccessibilityEvents {
     static func handleEventWindow(_ type: String, _ wid: CGWindowID, _ pid: pid_t, _ element: AXUIElement) throws {
         guard wid != 0 || type == kAXUIElementDestroyedNotification,
               wid != TilesPanel.shared.windowNumber else { return } // don't process events for the thumbnails panel
+        if type == kAXUIElementDestroyedNotification {
+            DispatchQueue.main.async {
+                Logger.info { "\(type) wid:\(wid) pid:\(pid)" }
+                windowDestroyed(element, pid, wid)
+            }
+            return
+        }
         let level = wid.level()
         let a = try element.attributes([kAXTitleAttribute, kAXSubroleAttribute, kAXRoleAttribute, kAXSizeAttribute, kAXPositionAttribute, kAXFullscreenAttribute, kAXMinimizedAttribute])
         DispatchQueue.main.async {
             guard let app = Applications.findOrCreate(pid, false) else { return }
             Logger.info { "\(type) wid:\(wid) app:\(app.debugId)" }
-            if type == kAXUIElementDestroyedNotification {
-                windowDestroyed(element, pid, wid)
-                return
-            }
             let findOrCreate = Windows.findOrCreate(element, wid, app, level, a.title, a.subrole, a.role, a.size, a.position, a.isFullscreen, a.isMinimized)
             guard let window = findOrCreate.0 else {
                 // we don't know this window, but it got focused, so let's update app.focusedWindow with nil