QSystemTrayIcon: handle submenus correctly

This fixes a bug when submenus are shown as simple actions when
a platform system tray icon is used.

To correctly handle submenus, we need to set platform menus on
all submenus, and only then on a parent menu.

Change-Id: If2bfcc703b938dbb14ba4b9aa810039ced07e946
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Dimitrios Glentadakis <dglent@free.fr>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

2 files changed, 24 insertions, 5 deletions

diff --git a/src/widgets/util/qsystemtrayicon.cpp b/src/widgets/util/qsystemtrayicon.cpp
index 7d04cab05e..d151e57d04 100644
--- a/src/widgets/util/qsystemtrayicon.cpp
+++ b/src/widgets/util/qsystemtrayicon.cpp
@@ -37,6 +37,7 @@
 #ifndef QT_NO_SYSTEMTRAYICON
 
 #include "qmenu.h"
+#include "qlist.h"
 #include "qevent.h"
 #include "qpoint.h"
 #include "qlabel.h"
@@ -704,11 +705,7 @@ void QSystemTrayIconPrivate::updateIcon_sys_qpa()
 void QSystemTrayIconPrivate::updateMenu_sys_qpa()
 {
     if (menu) {
-        if (!menu->platformMenu()) {
-            QPlatformMenu *platformMenu = qpa_sys->createMenu();
-            if (platformMenu)
-                menu->setPlatformMenu(platformMenu);
-        }
+        addPlatformMenu(menu);
         qpa_sys->updateMenu(menu->platformMenu());
     }
 }
@@ -741,6 +738,27 @@ void QSystemTrayIconPrivate::showMessage_sys_qpa(const QString &message,
                      static_cast<QPlatformSystemTrayIcon::MessageIcon>(icon), msecs);
 }
 
+void QSystemTrayIconPrivate::addPlatformMenu(QMenu *menu) const
+{
+    if (menu->platformMenu())
+        return; // The platform menu already exists.
+
+    // The recursion depth is the same as menu depth, so should not
+    // be higher than 3 levels.
+    QListIterator<QAction *> it(menu->actions());
+    while (it.hasNext()) {
+        QAction *action = it.next();
+        if (action->menu())
+            addPlatformMenu(action->menu());
+    }
+
+    // This menu should be processed *after* its children, otherwise
+    // setMenu() is not called on respective QPlatformMenuItems.
+    QPlatformMenu *platformMenu = qpa_sys->createMenu();
+    if (platformMenu)
+        menu->setPlatformMenu(platformMenu);
+}
+
 QT_END_NAMESPACE
 
 #endif // QT_NO_SYSTEMTRAYICON
diff --git a/src/widgets/util/qsystemtrayicon_p.h b/src/widgets/util/qsystemtrayicon_p.h
index 0dda689c51..f05bf9e3f9 100644
--- a/src/widgets/util/qsystemtrayicon_p.h
+++ b/src/widgets/util/qsystemtrayicon_p.h
@@ -99,6 +99,7 @@ private:
     void updateMenu_sys_qpa();
     QRect geometry_sys_qpa() const;
     void showMessage_sys_qpa(const QString &msg, const QString &title, QSystemTrayIcon::MessageIcon icon, int secs);
+    void addPlatformMenu(QMenu *menu) const;
 };
 
 class QBalloonTip : public QWidget