QMenu: Add support for QWidgetAction on Mac

The implementation follows a similar logic as in Qt 4
making sure we properly interface with the QPA backend.

We also make sure to delay moving the action widget to
the QPA menu until it's about to show. We still don't
support moving the action widget back from QPA world
into Qt, as explained in the QWidgetAction documentation.

Task-number: QTBUG-19840
Change-Id: I47f6359b0806f967d80c67fbb1f36c3d5ec8603e
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

src/widgets/widgets/qmenu.cpp

@@ -50,6 +50,9 @@
 #include "qlayout.h"
 #include "qpainter.h"
 #include <qpa/qplatformtheme.h>
+#ifdef Q_OS_OSX
+#include "qmacnativewidget_mac.h"
+#endif
 #include "qapplication.h"
 #include "qdesktopwidget.h"
 #ifndef QT_NO_ACCESSIBILITY
@@ -163,7 +166,7 @@ void QMenuPrivate::setPlatformMenu(QPlatformMenu *menu)
 
     platformMenu = menu;
     if (!platformMenu.isNull()) {
-        QObject::connect(platformMenu, SIGNAL(aboutToShow()), q, SIGNAL(aboutToShow()));
+        QObject::connect(platformMenu, SIGNAL(aboutToShow()), q, SLOT(_q_platformMenuAboutToShow()));
         QObject::connect(platformMenu, SIGNAL(aboutToHide()), q, SIGNAL(aboutToHide()));
     }
 }
@@ -1104,6 +1107,8 @@ void QMenuPrivate::_q_actionTriggered()
     Q_Q(QMenu);
     if (QAction *action = qobject_cast<QAction *>(q->sender())) {
         QPointer<QAction> actionGuard = action;
+        if (platformMenu && widgetItems.value(action))
+            platformMenu->dismiss();
         emit q->triggered(action);
         if (!activationRecursionGuard && actionGuard) {
             //in case the action has not been activated by the mouse
@@ -1134,6 +1139,24 @@ void QMenuPrivate::_q_actionHovered()
     }
 }
 
+void QMenuPrivate::_q_platformMenuAboutToShow()
+{
+    Q_Q(QMenu);
+
+#ifdef Q_OS_OSX
+    if (platformMenu)
+        Q_FOREACH (QAction *action, q->actions())
+            if (QWidget *widget = widgetItems.value(const_cast<QAction *>(action)))
+                if (widget->parent() == q) {
+                    QPlatformMenuItem *menuItem = platformMenu->menuItemForTag(reinterpret_cast<quintptr>(action));
+                    moveWidgetToPlatformItem(widget, menuItem);
+                    platformMenu->syncMenuItem(menuItem);
+                }
+#endif
+
+    emit q->aboutToShow();
+}
+
 bool QMenuPrivate::hasMouseMoved(const QPoint &globalPos)
 {
     //determines if the mouse has moved (ie its initial position has
@@ -2996,8 +3019,19 @@ void QMenu::actionEvent(QActionEvent *e)
         if (e->action() == d->currentAction)
             d->currentAction = 0;
         if (QWidgetAction *wa = qobject_cast<QWidgetAction *>(e->action())) {
-            if (QWidget *widget = d->widgetItems.value(wa))
+            if (QWidget *widget = d->widgetItems.value(wa)) {
+#ifdef Q_OS_OSX
+                QWidget *p = widget->parentWidget();
+                if (p != this && qobject_cast<QMacNativeWidget *>(p)) {
+                    // This widget was reparented into a native Mac view
+                    // (see QMenuPrivate::moveWidgetToPlatformItem).
+                    // Reset the parent and delete the native widget.
+                    widget->setParent(this);
+                    p->deleteLater();
+                }
+#endif
                 wa->releaseWidget(widget);
+            }
         }
         d->widgetItems.remove(e->action());
     }

src/widgets/widgets/qmenu.h

@@ -195,6 +195,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_actionTriggered())
     Q_PRIVATE_SLOT(d_func(), void _q_actionHovered())
     Q_PRIVATE_SLOT(d_func(), void _q_overrideMenuActionDestroyed())
+    Q_PRIVATE_SLOT(d_func(), void _q_platformMenuAboutToShow())
 
 protected:
     QMenu(QMenuPrivate &dd, QWidget* parent = 0);

src/widgets/widgets/qmenu_mac.mm

@@ -44,6 +44,8 @@
 
 #include "qmenu.h"
 #include "qmenubar.h"
+#include "qmenubar_p.h"
+#include "qmacnativewidget_mac.h"
 
 #include <QtCore/QDebug>
 #include <QtGui/QGuiApplication>
@@ -115,6 +117,23 @@ void QMenu::setAsDockMenu()
     \sa QMenu:setAsDockMenu()
 */
 
+void QMenuPrivate::moveWidgetToPlatformItem(QWidget *widget, QPlatformMenuItem* item)
+{
+    QMacNativeWidget *container = new QMacNativeWidget;
+    QObject::connect(platformMenu, SIGNAL(destroyed()), container, SLOT(deleteLater()));
+    container->resize(widget->sizeHint());
+    widget->setParent(container);
+
+    NSView *containerView = container->nativeView();
+    QWindow *containerWindow = container->windowHandle();
+    Qt::WindowFlags wf = containerWindow->flags();
+    containerWindow->setFlags(wf | Qt::SubWindow);
+    [(NSView *)widget->winId() setAutoresizingMask:NSViewWidthSizable];
+
+    item->setNativeContents((WId)containerView);
+    container->show();
+}
+
 #endif //QT_NO_MENU
 
 #ifndef QT_NO_MENUBAR

src/widgets/widgets/qmenu_p.h

@@ -110,6 +110,9 @@ public:
     void init();
     void setPlatformMenu(QPlatformMenu *menu);
     void syncPlatformMenu();
+#ifdef Q_OS_OSX
+    void moveWidgetToPlatformItem(QWidget *w, QPlatformMenuItem* item);
+#endif
 
     static QMenuPrivate *get(QMenu *m) { return m->d_func(); }
     int scrollerHeight() const;
@@ -223,6 +226,7 @@ public:
 
     void _q_actionTriggered();
     void _q_actionHovered();
+    void _q_platformMenuAboutToShow();
 
     bool hasMouseMoved(const QPoint &globalPos);