Cocoa, 64-bit, 10.10 and later: use MMTabBarView

On 10.11 in 64-bit mode, showing a frame with a PSMTabBarControl
instance somehow causes the event loop to become occupied on
mouse movements, so that moving the mouse in a `2htdp/universe`
program is slow when more than one tab is open in DrRacket. The
modern MMTabBarView widget doesn't have that problem. Also, the
MMTabBarView widget has a Yosemite look (to replace Aqua).

gui-lib/mred/private/wx/cocoa/tab-panel.rkt

@@ -19,15 +19,33 @@
 
 (define-runtime-path psm-tab-bar-dir
   '(so "PSMTabBarControl.framework"))
-
-;; Load PSMTabBarControl:
-(void (ffi-lib (build-path psm-tab-bar-dir "PSMTabBarControl")))
+(define-runtime-path mm-tab-bar-dir
+  ;; This directory will not exist for platforms other than x86_64:
+  '(so "MMTabBarView.framework"))
+
+(define use-mm?
+  (and (version-10.10-or-later?)
+       64-bit?
+       (directory-exists? mm-tab-bar-dir)))
+
+;; Load MMTabBarView or PSMTabBarControl:
+(if use-mm?
+    (void (ffi-lib (build-path mm-tab-bar-dir "MMTabBarView")))
+    (void (ffi-lib (build-path psm-tab-bar-dir "PSMTabBarControl"))))
 (define NSNoTabsNoBorder 6)
 
 (define NSDefaultControlTint 0)
 (define NSClearControlTint 7)
 
-(import-class NSView NSTabView NSTabViewItem PSMTabBarControl)
+(import-class NSView NSTabView NSTabViewItem)
+(define TabBarControl
+  (if use-mm?
+      (let ()
+        (import-class MMTabBarView)
+        MMTabBarView)
+      (let ()
+        (import-class PSMTabBarControl)
+        PSMTabBarControl)))
 (import-protocol NSTabViewDelegate)
 
 (define NSOrderedAscending -1)
@@ -49,7 +67,7 @@
         (when (and wx (send wx callbacks-enabled?))
           (queue-window*-event wxb (lambda (wx) (send wx do-callback)))))))
 
-(define-objc-class RacketPSMTabBarControl PSMTabBarControl
+(define-objc-class RacketPSMTabBarControl TabBarControl
   #:mixins (FocusResponder KeyMouseResponder CursorDisplayer)
   [wxb]
   (-a _void (tabView: [_id cocoa] didSelectTabViewItem: [_id item-cocoa])
@@ -83,8 +101,10 @@
            (tellv tabv-cocoa setDelegate: i)
            (tellv tabv-cocoa setTabViewType: #:type _int NSNoTabsNoBorder)
            (tellv i setTabView: tabv-cocoa)
-           (tellv i setStyleNamed: #:type _NSString "Aqua")
-           ;;(tellv i setSizeCellsToFit: #:type _BOOL #t)
+           (tellv i setStyleNamed: #:type _NSString (if use-mm? "Yosemite" "Aqua"))
+           ;; (tellv i setSizeCellsToFit: #:type _BOOL #t)
+           (when use-mm?
+             (tellv i setResizeTabsToFitTotalWidth: #:type _BOOL #t))
            (tellv i setDisableTabClose: #:type _BOOL #t)
            i)))
 

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

@@ -21,8 +21,6 @@
 
 (define _OSStatus _sint32)
 
-(define 64-bit? (= (ctype-sizeof _long) 8))
-
 (define _CGFloat (make-ctype (if 64-bit? _double _float)
                              (lambda (v) (if (and (number? v)
                                                   (exact? v))

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

@@ -21,6 +21,7 @@
               clean-menu-label
               ->wxb
               ->wx
+              64-bit?
               old-cocoa?
               version-10.6-or-later?
               version-10.7-or-later?
@@ -74,6 +75,8 @@
   (and wxb
        (weak-box-value wxb)))
 
+(define 64-bit? (= (ctype-sizeof _long) 8))
+
 (define-appkit NSAppKitVersionNumber _double)
 
 (define old-cocoa?