linux & mac support, refactoring on minimize

examples/simple.rkt

@@ -5,10 +5,12 @@
 
 ;; This example demonstrates the two common "close to tray" behaviours:
 ;;
-;;   * minimize: handled by racket-tray through #:hide-on-minimize?
+;;   * minimize: handled portably by racket-tray through
+;;               #:hide-on-minimize?
 ;;   * close [X]: handled by frame%'s normal on-close callback
 ;;
-;; The frame remains alive in both cases because the tray icon uses its HWND.
+;; The frame remains alive in both cases. Only the tray menu's Exit action
+;; terminates the application.
 (define simple%
   (class frame%
     (super-new [label "Racket Tray"]
@@ -17,7 +19,7 @@
 
     (define lbl
       (new message%
-           [label "Counting tray clicks"]
+           [label "Counting tray activations"]
            [parent this]
            [auto-resize #t]
            [stretchable-width #t]))
@@ -27,11 +29,11 @@
     (define/public (count-next)
       (set! count (add1 count))
       (send lbl set-label
-            (format "Counting tray clicks: ~a" count)))
+            (format "Counting tray activations: ~a" count)))
 
     ;; Clicking the window's close button hides the frame instead of
     ;; destroying it. The tray menu's Exit item terminates the application.
-    (define/override (on-close)
+    (define/augment (on-close)
       (send this show #f))))
 
 (define frame (new simple%))
@@ -42,32 +44,44 @@
 ; post   : frame is visible and no longer iconized.
 ; result : Unspecified.
 ; internals:
-;          A frame hidden in response to SIZE_MINIMIZED can still retain its
-;          iconized state, so show #t is followed by iconize #f when needed.
+;          The portable minimize watcher hides an iconized frame. Explicitly
+;          de-iconizing here makes restoring predictable on every platform.
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 (define (show-frame)
-  ;; A frame hidden after a minimize can still be iconized. Make sure it is
-  ;; restored when it is opened from the tray.
   (send frame show #t)
   (when (send frame is-iconized?)
     (send frame iconize #f)))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+; goal   : Handle every symbolic action generated by the tray icon/menu.
+; pre    : action is one of the identifiers installed with tray-set-menu!.
+; post   : 'open restores the frame and increments the counter; 'exit removes
+;          the tray icon and terminates the example.
+; result : Unspecified.
+; internals:
+;          The same callback is used for menu selections and for native direct
+;          activation on platforms that support the configured default action.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+(define (tray-action action)
+  (case action
+    [(open)
+     (send frame count-next)
+     (show-frame)]
+    [(exit)
+     (tray-close tray)
+     (exit)]))
+
 (define tray
   (mk-tray frame
            "simple.png"
-           (λ ()
-             (send frame count-next)
-             (show-frame))
+           (list tray-action 'open)
            #:hide-on-minimize? #t))
 
 (tray-set-menu!
  tray
  (list
-  (list "Open" show-frame)
+  (list 'open "Open")
   'separator
-  (list "Exit"
-        (λ ()
-          (tray-close tray)
-          (exit)))))
+  (list 'exit "Exit")))
 
 (send frame show #t)