racket/gui gtk: catch key events at frame level

In case no subwindow within a frame can accept the keyboard
focus, now the frame itself can accept them (for consumption
by `on-subwindow-char').

collects/mred/private/wx/gtk/frame.rkt

@@ -179,6 +179,15 @@
     (gtk_widget_show panel-gtk)
     (connect-enter-and-leave gtk)
 
+    ;; Enable key events on the panel to catch events
+    ;; that would otherwise go undelivered:
+    (set-gtk-object-flags! panel-gtk
+			   (bitwise-ior (get-gtk-object-flags panel-gtk)
+					GTK_CAN_FOCUS))
+    (gtk_widget_add_events panel-gtk (bitwise-ior GDK_KEY_PRESS_MASK
+						  GDK_KEY_RELEASE_MASK))
+    (connect-key panel-gtk)
+
     (unless is-dialog?
       (gtk_window_set_icon_list gtk (cdr (force icon-pixbufs+glist))))
 

collects/mred/private/wx/gtk/window.rkt

@@ -34,6 +34,7 @@
               gtk_widget_set_sensitive
 
               connect-focus
+              connect-key
               connect-key-and-mouse
               connect-enter-and-leave
               do-button-event
@@ -302,9 +303,12 @@
   (connect-enter gtk)
   (connect-leave gtk))
 
-(define (connect-key-and-mouse gtk [skip-press? #f])
+(define (connect-key gtk)
   (connect-key-press gtk)
-  (connect-key-release gtk)
+  (connect-key-release gtk))
+
+(define (connect-key-and-mouse gtk [skip-press? #f])
+  (connect-key gtk)
   (connect-scroll gtk)
   (connect-button-press gtk)
   (unless skip-press? (connect-button-release gtk))