macOS: allow Qt::AA_DontShowShortcutsInContextMenus overrides

Following the discussion in QTBUG-69452, the resulting change in
cc33dd079796437bafed8f42de7fbf8f17d19ec8, and the documentation of
QAction::shortcutVisibleInContextMenu, the intention is that the
attribute allows the overriding of the platform default.

However, QAction did ask both the attribute and the platform
integration, making the override impossible. Instead, ask only
the attribute, but default the value of the attribute to what the
platform integration provides.

[ChangeLog][QtGui][QAction] The shortcutVisibleInContextMenu property
defaults to the value of the Qt::AA_DontShowShortcutsInContextMenus
attribute, which in turn defaults to the platform integration. To
override the default, set the application attribute after
instantiating QApplication, or override the default for each
QAction instance.

Task-number: QTBUG-73990
Change-Id: Iaba330913555d93d05efe1b3965a6aea39db5554
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 68297195759492594ac4143b7f208e17fe6f594b)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/global/qnamespace.qdoc

@@ -118,7 +118,9 @@
     \value AA_DontShowShortcutsInContextMenus Actions with the Shortcut property
            won't be shown in any shortcut menus unless specifically set by the
            QAction::shortcutVisibleInContextMenu property. This value was added
-           in Qt 5.10.
+           in Qt 5.10, and defaults to the preference reported by the implementation
+           of QPlatformIntegration::styleHint. To override the platform integration,
+           set this attribute after QCoreApplication has been instantiated.
 
     \value AA_NativeWindows Ensures that widgets have native windows.
 

src/gui/kernel/qaction.cpp

@@ -1301,8 +1301,7 @@ bool QAction::isIconVisibleInMenu() const
     shown via a context menu, when it is false, it is not shown.
 
     The default is to follow whether the Qt::AA_DontShowShortcutsInContextMenus attribute
-    is set for the application, falling back to the widget style hint.
-    Explicitly setting this property overrides the presence (or abscence) of the attribute.
+    is set for the application. Explicitly setting this property overrides the attribute.
 
     \sa shortcut, QCoreApplication::setAttribute()
 */
@@ -1323,10 +1322,8 @@ void QAction::setShortcutVisibleInContextMenu(bool visible)
 bool QAction::isShortcutVisibleInContextMenu() const
 {
     Q_D(const QAction);
-    if (d->shortcutVisibleInContextMenu == -1) {
-        return !QCoreApplication::testAttribute(Qt::AA_DontShowShortcutsInContextMenus)
-            && QGuiApplication::styleHints()->showShortcutsInContextMenus();
-    }
+    if (d->shortcutVisibleInContextMenu == -1)
+        return !QCoreApplication::testAttribute(Qt::AA_DontShowShortcutsInContextMenus);
     return d->shortcutVisibleInContextMenu;
 }
 

src/gui/kernel/qguiapplication.cpp

@@ -1304,7 +1304,10 @@ static void init_platform(const QString &pluginNamesWithArguments, const QString
     }
 #endif
 
-    fontSmoothingGamma = QGuiApplicationPrivate::platformIntegration()->styleHint(QPlatformIntegration::FontSmoothingGamma).toReal();
+    const auto platformIntegration = QGuiApplicationPrivate::platformIntegration();
+    fontSmoothingGamma = platformIntegration->styleHint(QPlatformIntegration::FontSmoothingGamma).toReal();
+    QCoreApplication::setAttribute(Qt::AA_DontShowShortcutsInContextMenus,
+        !platformIntegration->styleHint(QPlatformIntegration::ShowShortcutsInContextMenus).toBool());
 }
 
 static void init_plugins(const QList<QByteArray> &pluginList)

src/widgets/widgets/qlineedit.cpp

@@ -83,8 +83,7 @@
 #include "private/qapplication_p.h"
 #include "private/qshortcutmap_p.h"
 #include "qkeysequence.h"
-#define ACCEL_KEY(k) ((!QCoreApplication::testAttribute(Qt::AA_DontShowIconsInMenus) \
-                        && QGuiApplication::styleHints()->showShortcutsInContextMenus()) \
+#define ACCEL_KEY(k) (!QCoreApplication::testAttribute(Qt::AA_DontShowShortcutsInContextMenus) \
                       && !QGuiApplicationPrivate::instance()->shortcutMap.hasShortcutForKeySequence(k) ? \
                       QLatin1Char('\t') + QKeySequence(k).toString(QKeySequence::NativeText) : QString())
 #else

src/widgets/widgets/qwidgettextcontrol.cpp

@@ -98,8 +98,7 @@
 #include "private/qapplication_p.h"
 #include "private/qshortcutmap_p.h"
 #include <qkeysequence.h>
-#define ACCEL_KEY(k) ((!QCoreApplication::testAttribute(Qt::AA_DontShowShortcutsInContextMenus) \
-                       && QGuiApplication::styleHints()->showShortcutsInContextMenus()) \
+#define ACCEL_KEY(k) (!QCoreApplication::testAttribute(Qt::AA_DontShowShortcutsInContextMenus) \
                       && !QGuiApplicationPrivate::instance()->shortcutMap.hasShortcutForKeySequence(k) ? \
                       QLatin1Char('\t') + QKeySequence(k).toString(QKeySequence::NativeText) : QString())