fix: apps could steal key focus from alt-tab main window (#719 #916)

(closes #719, closes #916)

src/logic/SystemPermissions.swift

@@ -93,7 +93,7 @@ class SystemPermissions {
             startupBlock()
         } else {
             permissionsWindow = PermissionsWindow()
-            permissionsWindow.show()
+            App.app.showSecondaryWindow(permissionsWindow)
             observePermissionsPreStartup(startupBlock)
         }
     }

src/logic/Window.swift

@@ -216,5 +216,12 @@ class Window {
             isOnAllSpaces = true
         }
     }
+
+    func isOnScreen(_ screen: NSScreen) -> Bool {
+        if let screenUuid = screen.uuid(), let screenSpaces = Spaces.screenSpacesMap[screenUuid] {
+            return screenSpaces.contains { $0 == spaceId }
+        }
+        return true
+    }
 }
 

src/logic/Windows.swift

@@ -181,30 +181,9 @@ class Windows {
                 !(!(Preferences.showMinimizedWindows[App.app.shortcutIndex] != .hide) && window.isMinimized) &&
                 !(Preferences.spacesToShow[App.app.shortcutIndex] == .active && window.spaceId != Spaces.currentSpaceId) &&
                 !(Preferences.spacesToShow[App.app.shortcutIndex] == .visible && !Spaces.visibleSpaces.contains(window.spaceId)) &&
-                !(Preferences.screensToShow[App.app.shortcutIndex] == .showingAltTab && !isOnScreen(window, screen)) &&
+                !(Preferences.screensToShow[App.app.shortcutIndex] == .showingAltTab && !window.isOnScreen(screen)) &&
                 (Preferences.showTabsAsWindows || !window.isTabbed))
     }
-
-    static func isOnScreen(_ window: Window, _ screen: NSScreen) -> Bool {
-        if let screenUuid = screen.uuid(), let screenSpaces = Spaces.screenSpacesMap[screenUuid] {
-            return screenSpaces.contains { $0 == window.spaceId }
-        }
-        return true
-    }
-
-    static func checkIfShortcutsShouldBeDisabled(_ activeWindow: Window) {
-        let shortcutsShouldBeDisabled = (!Preferences.disableShortcutsBlacklistOnlyFullscreen || activeWindow.isFullscreen) &&
-            (Preferences.disableShortcutsBlacklist.first { blacklistedId in
-                if let id = activeWindow.application.runningApplication.bundleIdentifier {
-                    return id.hasPrefix(blacklistedId)
-                }
-                return false
-            } != nil)
-        KeyboardEvents.toggleGlobalShortcuts(shortcutsShouldBeDisabled)
-        if shortcutsShouldBeDisabled && App.app.appIsBeingUsed {
-            App.app.hideUi()
-        }
-    }
 }
 
 func sortByBooleanAttribute(_ b1: Bool, _ b2: Bool) -> Bool? {

src/logic/events/AccessibilityEvents.swift

@@ -36,18 +36,16 @@ fileprivate func focusedUiElementChanged(_ pid: pid_t) throws {
 }
 
 fileprivate func applicationActivated(_ element: AXUIElement, _ pid: pid_t) throws {
-    if let appFocusedWindow = try element.focusedWindow(),
-       let wid = try appFocusedWindow.cgWindowId() {
-        DispatchQueue.main.async {
-            if let app = (Applications.list.first { $0.pid == pid }), !app.hasBeenActiveOnce {
+    let appFocusedWindow = try element.focusedWindow()
+    let wid = try appFocusedWindow?.cgWindowId()
+    DispatchQueue.main.async {
+        if let app = (Applications.list.first { $0.pid == pid }) {
+            if !app.hasBeenActiveOnce {
                 app.hasBeenActiveOnce = true
             }
-            // ensure alt-tab window remains key, so local shortcuts work
-            if App.app.appIsBeingUsed { App.app.thumbnailsPanel.makeKeyAndOrderFront(nil) }
-            if let window = Windows.updateLastFocus(appFocusedWindow, wid) {
-                Windows.checkIfShortcutsShouldBeDisabled(window.first!)
-                App.app.refreshOpenUi(window)
-            }
+            let window = (appFocusedWindow != nil && wid != nil) ? Windows.updateLastFocus(appFocusedWindow!, wid!)?.first : nil
+            App.app.checkIfShortcutsShouldBeDisabled(window, app.runningApplication)
+            App.app.refreshOpenUi(window != nil ? [window!] : nil)
         }
     }
 }
@@ -187,7 +185,7 @@ fileprivate func windowResized(_ element: AXUIElement) throws {
             if let window = (Windows.list.first { $0.isEqualRobust(element, wid) }) {
                 if window.isFullscreen != isFullscreen {
                     window.isFullscreen = isFullscreen
-                    Windows.checkIfShortcutsShouldBeDisabled(window)
+                    App.app.checkIfShortcutsShouldBeDisabled(window, nil)
                 }
                 App.app.refreshOpenUi([window])
             }

src/ui/App.swift

@@ -282,4 +282,19 @@ class App: AppCenterApplication, NSApplicationDelegate {
         Applications.refreshBadges()
         KeyRepeatTimer.toggleRepeatingKeyNextWindow()
     }
+
+    func checkIfShortcutsShouldBeDisabled(_ activeWindow: Window?, _ activeApp: NSRunningApplication?) {
+        let app = activeWindow?.application.runningApplication ?? activeApp
+        let shortcutsShouldBeDisabled = (!Preferences.disableShortcutsBlacklistOnlyFullscreen || (activeWindow?.isFullscreen ?? false)) &&
+            (Preferences.disableShortcutsBlacklist.first { blacklistedId in
+                if let id = app?.bundleIdentifier {
+                    return id.hasPrefix(blacklistedId)
+                }
+                return false
+            } != nil)
+        KeyboardEvents.toggleGlobalShortcuts(shortcutsShouldBeDisabled)
+        if shortcutsShouldBeDisabled && App.app.appIsBeingUsed {
+            App.app.hideUi()
+        }
+    }
 }

src/ui/main-window/ThumbnailsPanel.swift

@@ -1,11 +1,12 @@
 import Cocoa
 
-class ThumbnailsPanel: NSPanel {
+class ThumbnailsPanel: NSPanel, NSWindowDelegate {
     var thumbnailsView = ThumbnailsView()
     override var canBecomeKey: Bool { true }
 
     convenience init() {
         self.init(contentRect: .zero, styleMask: .nonactivatingPanel, backing: .buffered, defer: false)
+        delegate = self
         isFloatingPanel = true
         updateFadeOutAnimation()
         hidesOnDeactivate = false
@@ -24,6 +25,16 @@ class ThumbnailsPanel: NSPanel {
         setAccessibilitySubrole(.unknown)
     }
 
+    func windowDidResignKey(_ notification: Notification) {
+        // other windows can steal key focus from alt-tab; we make sure that if it's active, if keeps key focus
+        // dispatching to the main queue is necessary to introduce a delay in scheduling the makeKey; otherwise it is ignored
+        DispatchQueue.main.async {
+            if App.app.appIsBeingUsed {
+                App.app.thumbnailsPanel.makeKeyAndOrderFront(nil)
+            }
+        }
+    }
+
     func updateFadeOutAnimation() {
         animationBehavior = Preferences.fadeOutAnimation ? .utilityWindow : .none
     }

src/ui/permission-window/PermissionsWindow.swift

@@ -11,12 +11,6 @@ class PermissionsWindow: NSWindow, NSWindowDelegate {
         setupView()
     }
 
-    func show() {
-        center()
-        App.shared.activate(ignoringOtherApps: true)
-        makeKeyAndOrderFront(nil)
-    }
-
     func windowShouldClose(_ sender: NSWindow) -> Bool {
         debugPrint("Before using this app, you need to give permission in System Preferences > Security & Privacy > Privacy > Accessibility.",
             "Please authorize and re-launch.",