fix: duplicate windows shown after login (closes #292)

src/api-wrappers/AXUIElement.swift

@@ -16,13 +16,14 @@ extension AXUIElement {
     }
 
     func isActualWindow(_ bundleIdentifier: String?) -> Bool {
+        // Some non-windows have cgWindowId == 0 (e.g. windows of apps starting at login with the checkbox "Hidden" checked)
         // Some non-windows have title: nil (e.g. some OS elements)
         // Some non-windows have subrole: nil (e.g. some OS elements), "AXUnknown" (e.g. Bartender), "AXSystemDialog" (e.g. Intellij tooltips)
         // Minimized windows or windows of a hidden app have subrole "AXDialog"
         // Activity Monitor main window subrole is "AXDialog" for a brief moment at launch; it then becomes "AXStandardWindow"
         // CGWindowLevel == .normalWindow helps filter out iStats Pro and other top-level pop-overs
         let subrole_ = subrole()
-        return subrole_ != nil &&
+        return cgWindowId() != 0 && subrole_ != nil &&
             (["AXStandardWindow", "AXDialog"].contains(subrole_) ||
                 // All Steam windows have subrole = AXUnknown
                 // some dropdown menus are not desirable; they have title == "", or sometimes role == nil when switching between menus quickly

src/api-wrappers/HelperExtensions.swift

@@ -17,9 +17,9 @@ extension NSObject {
 
 extension Array where Element == Window {
     func firstIndexThatMatches(_ element: AXUIElement) -> Self.Index? {
-        // == is safer than comparing `CGWindowID` because it will succeed even if the window is deallocated
-        // by the OS, in which case the `CGWindowID` will be `-1`
-        return firstIndex(where: { $0.axUiElement == element })
+        // the window can be deallocated by the OS, in which case its `CGWindowID` will be `-1`
+        // we check for equality both on the AXUIElement, and the CGWindowID, in order to catch all scenarios
+        return firstIndex(where: { $0.axUiElement == element || ($0.cgWindowId != -1 && $0.cgWindowId == element.cgWindowId()) })
     }
 
     mutating func insertAndScaleRecycledPool(_ elements: [Element], at i: Int) {

src/logic/Application.swift

@@ -52,7 +52,8 @@ class Application: NSObject {
     func observeNewWindows() {
         if let windows = (axUiElement!.windows()?
             .filter { $0.isActualWindow(runningApplication.bundleIdentifier) }) {
-            let actualWindows = windows.filter { Windows.list.firstIndexThatMatches($0) == nil }
+            // bug in macOS: sometimes the OS returns multiple duplicate windows (e.g. Mail.app starting at login)
+            let actualWindows = Array(Set(windows.filter { Windows.list.firstIndexThatMatches($0) == nil }))
             if actualWindows.count > 0 {
                 addWindows(actualWindows)
             }