Mac OS: handle menu keys when no windows are open

An original assumption about a hidden fake root window was broken in
some Mac OS vesion after Catalina and before Sequoia. Finally add a
hook to redirect key events to the fake root frame when they're not
received by another other window.

Author: mflatt

gui-lib/mred/private/wx/cocoa/const.rkt

@@ -39,6 +39,7 @@
 (define NSOtherMouseDown 25)
 (define NSOtherMouseUp 26)
 (define NSOtherMouseDragged 27)
+(define NSEventTypeKeyDown 10)
 (define NSEventTypeGesture 29)
 (define NSEventTypeMagnify 30)
 (define NSEventTypeSwipe 31)

gui-lib/mred/private/wx/cocoa/frame.rkt

@@ -863,6 +863,14 @@
        (when f
          (send f fixup-locations-children))))))
 
+(set-post-key-callback-hook!
+ (lambda (evt)
+   (key-event-received #f)
+   (and root-fake-frame
+        (lambda (evt)
+          (unless (key-event-received)
+            (tellv (send root-fake-frame get-cocoa) keyDown: evt))))))
+
 ;; ----------------------------------------
 ;; As of Mac OS 10.14, NSWindow-specific flushing control is no longer
 ;; supported. It seems to have been removed as a way of simplifying the

gui-lib/mred/private/wx/cocoa/queue.rkt

@@ -24,6 +24,7 @@
               set-front-hook!
               set-menu-bar-hooks!
               set-mouse-or-key-hook!
+              set-post-key-callback-hook!
               set-fixup-window-locations!
               post-dummy-event
 
@@ -426,6 +427,9 @@
 (define front-hook (lambda () (values #f #f)))
 (define (set-front-hook! proc) (set! front-hook proc))
 
+(define get-post-key-callback (lambda () #f))
+(define (set-post-key-callback-hook! proc) (set! get-post-key-callback proc))
+
 (define in-menu-bar-range? (lambda (p flipped?) #f))
 (define (set-menu-bar-hooks! r?) 
   (set! in-menu-bar-range? r?))
@@ -525,8 +529,14 @@
                                           (lambda ()
                                             ;; in atomic mode
                                             (with-autorelease
-                                             (tellv app sendEvent: evt)
-                                             (release evt))))
+                                              (define post-key
+                                                (and (not w)
+                                                     (= NSEventTypeKeyDown (tell #:type _NSUInteger evt type))
+                                                     (not (tell app keyWindow))
+                                                     (get-post-key-callback evt)))
+                                              (tellv app sendEvent: evt)
+                                              (when post-key (post-key evt))
+                                              (release evt))))
                                          (when mouse-or-key?
                                            (set! avoid-mouse-key-until #f)))))
                       (tellv app sendEvent: evt)))

gui-lib/mred/private/wx/cocoa/window.rkt

@@ -26,6 +26,8 @@
               KeyMouseTextResponder
               CursorDisplayer
 
+              key-event-received
+
               queue-window-event
               queue-window-refresh-event
               queue-window*-event
@@ -302,6 +304,7 @@
      (let ([inserted-text (box #f)]
            [set-mark (box #f)]
            [had-saved-text? (and (send wx get-saved-marked) #t)])
+       (key-event-received #t)
        (when down?
          ;; Calling `interpretKeyEvents:' allows key combinations to be
          ;; handled, such as option-e followed by e to produce é. The
@@ -1111,6 +1114,14 @@
 
 ;; ----------------------------------------
 
+(define key-event-received? #f)
+(define key-event-received
+  (case-lambda
+    [() key-event-received?]
+    [(received?) (set! key-event-received? received?)]))
+
+;; ----------------------------------------
+
 (define (queue-window-event wx thunk)
   (queue-event (send wx get-eventspace) thunk))