Cocoa: fix quick access terminal hide focus restore

Apple now makes kitty the front most application before sending the
service notification. So instead watch for front most application change
events from the shared workspace and restore focus to the last non-self
application.

docs/changelog.rst

@@ -115,6 +115,9 @@ Detailed list of changes
 - Wayland: Fix incorrect window size calculation when transitioning from
   fullscreen to non-fullscreen with client side decorations (:iss:`8826`)
 
+- macOS: Fix hiding quick access terminal window not restoring focus to
+  previously active application (:disc:`8840`)
+
 0.42.2 [2025-07-16]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

glfw/cocoa_init.m

@@ -301,6 +301,14 @@ @interface GLFWApplicationDelegate : NSObject <NSApplicationDelegate>
 
 @implementation GLFWApplicationDelegate
 
+- (void)applicationDidActivate:(NSNotification *)notification {
+    NSRunningApplication *app = notification.userInfo[NSWorkspaceApplicationKey];
+    if (app && app.processIdentifier != getpid()) {
+        _glfw.ns.previous_front_most_application = app.processIdentifier;
+        debug_rendering("Front most application changed to: %s pid: %d\n", app.bundleIdentifier.UTF8String, app.processIdentifier)
+    }
+}
+
 - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
 {
     (void)sender;
@@ -452,6 +460,7 @@ - (void)render_frame_received:(id)displayIDAsID
     CGDirectDisplayID displayID = [(NSNumber*)displayIDAsID unsignedIntValue];
     _glfwDispatchRenderFrame(displayID);
 }
+
 @end
 
 
@@ -816,6 +825,11 @@ int _glfwPlatformInit(bool *supports_window_occlusion)
     }
 
     [NSApp setDelegate:_glfw.ns.delegate];
+    [[[NSWorkspace sharedWorkspace] notificationCenter]
+        addObserver:_glfw.ns.delegate
+        selector:@selector(applicationDidActivate:)
+        name:NSWorkspaceDidActivateApplicationNotification
+        object:nil];
     static struct {
         unsigned short virtual_key_code;
         NSEventModifierFlags input_source_switch_modifiers;

glfw/cocoa_platform.h

@@ -125,7 +125,6 @@ typedef struct _GLFWwindowNS
     id              delegate;
     id              view;
     id              layer;
-    pid_t           previous_front_most_application;
 
     bool            maximized;
     bool            retina;
@@ -189,6 +188,7 @@ typedef struct _GLFWlibraryNS
     double              restoreCursorPosX, restoreCursorPosY;
     // The window whose disabled cursor mode is active
     _GLFWwindow*        disabledCursorWindow;
+    pid_t           previous_front_most_application;
 
     struct {
         CFBundleRef     bundle;

glfw/cocoa_window.m

@@ -2228,20 +2228,15 @@ void _glfwPlatformMaximizeWindow(_GLFWwindow* window)
 
 void _glfwPlatformShowWindow(_GLFWwindow* window)
 {
-    NSRunningApplication *app = [[NSWorkspace sharedWorkspace] frontmostApplication];
-    window->ns.previous_front_most_application = 0;
-    if (app && app.processIdentifier != getpid()) window->ns.previous_front_most_application = app.processIdentifier;
     if (window->ns.layer_shell.is_active && window->ns.layer_shell.config.type == GLFW_LAYER_SHELL_BACKGROUND) {
         [window->ns.object orderBack:nil];
     } else [window->ns.object orderFront:nil];
-    debug("Previously active application pid: %d bundle identifier: %s\n",
-        window->ns.previous_front_most_application, app ? app.bundleIdentifier.UTF8String : "");
 }
 
 void _glfwPlatformHideWindow(_GLFWwindow* window)
 {
     [window->ns.object orderOut:nil];
-    pid_t prev_app_pid = window->ns.previous_front_most_application; window->ns.previous_front_most_application = 0;
+    pid_t prev_app_pid = _glfw.ns.previous_front_most_application; _glfw.ns.previous_front_most_application = 0;
     NSRunningApplication *app;
     if (window->ns.layer_shell.is_active && prev_app_pid > 0 && (app = [NSRunningApplication runningApplicationWithProcessIdentifier:prev_app_pid])) {
         unsigned num_visible = 0;