fix: better identify tabs on macos versions older than 13

closes #2017

src/api-wrappers/PrivateApis.swift

@@ -112,10 +112,10 @@ func CGSCopyManagedDisplaySpaces(_ cid: CGSConnectionID) -> CFArray
 
 struct CGSCopyWindowsOptions: OptionSet {
     let rawValue: Int
-    static let minimizedAndTabbed = CGSCopyWindowsOptions(rawValue: 1 << 0)
+    static let invisible1 = CGSCopyWindowsOptions(rawValue: 1 << 0)
     // retrieves windows when their app is assigned to All Spaces, and windows at ScreenSaver level 1000
     static let screenSaverLevel1000 = CGSCopyWindowsOptions(rawValue: 1 << 1)
-    static let minimized2 = CGSCopyWindowsOptions(rawValue: 1 << 2)
+    static let invisible2 = CGSCopyWindowsOptions(rawValue: 1 << 2)
     static let unknown1 = CGSCopyWindowsOptions(rawValue: 1 << 3)
     static let unknown2 = CGSCopyWindowsOptions(rawValue: 1 << 4)
     static let desktopIconWindowLevel2147483603 = CGSCopyWindowsOptions(rawValue: 1 << 5)

src/logic/Spaces.swift

@@ -69,11 +69,14 @@ class Spaces {
         return idsAndIndexes.filter { $0.0 != currentSpaceId }.map { $0.0 }
     }
 
-    static func windowsInSpaces(_ spaceIds: [CGSSpaceID]) -> [CGWindowID] {
+    static func windowsInSpaces(_ spaceIds: [CGSSpaceID], _ includeInvisible: Bool = true) -> [CGWindowID] {
         var set_tags = ([] as CGSCopyWindowsTags).rawValue
         var clear_tags = ([] as CGSCopyWindowsTags).rawValue
-        let options = ([.minimizedAndTabbed, .screenSaverLevel1000] as CGSCopyWindowsOptions).rawValue
-        return CGSCopyWindowsWithOptionsAndTags(cgsMainConnectionId, 0, spaceIds as CFArray, options, &set_tags, &clear_tags) as! [CGWindowID]
+        var options = [.screenSaverLevel1000] as CGSCopyWindowsOptions
+        if includeInvisible {
+            options = [options, .invisible1, .invisible2]
+        }
+        return CGSCopyWindowsWithOptionsAndTags(cgsMainConnectionId, 0, spaceIds as CFArray, options.rawValue, &set_tags, &clear_tags) as! [CGWindowID]
     }
 
     static func isSingleSpace() -> Bool {

src/logic/Windows.swift

@@ -228,10 +228,21 @@ class Windows {
     /// tabs detection is a flaky work-around the lack of public API to observe OS tabs
     /// see: https://github.com/lwouis/alt-tab-macos/issues/1540
     static func detectTabbedWindows() {
-        let cgsWindowIds = Spaces.windowsInSpaces(Spaces.idsAndIndexes.map { $0.0 })
+        lazy var cgsWindowIds = Spaces.windowsInSpaces(Spaces.idsAndIndexes.map { $0.0 })
+        lazy var visibleCgsWindowIds = Spaces.windowsInSpaces(Spaces.idsAndIndexes.map { $0.0 }, false)
         list.forEach {
             if let cgWindowId = $0.cgWindowId {
-                $0.isTabbed = !cgsWindowIds.contains(cgWindowId)
+                if $0.isMinimized || $0.isHidden {
+                    if #available(macOS 13, *) {
+                        // not exact after window merging
+                        $0.isTabbed = !cgsWindowIds.contains(cgWindowId)
+                    } else {
+                        // not known
+                        $0.isTabbed = false
+                    }
+                } else {
+                    $0.isTabbed = !visibleCgsWindowIds.contains(cgWindowId)
+                }
             }
         }
     }