Fix QWidget::setWindowRole()

Introduce QXcbWindowFunctions::setWmWindowRole() and call it either from
the implementation of QWidget::setWindowRole() or after the creation of
the corresponding QWidgetWindow.

Change-Id: I143450f4673dd707bb491c1d0f0e8b61d564283d
Task-number: QTBUG-45484
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
Reviewed-by: Ivan Čukić <ivan.cukic@kde.org>

src/platformheaders/xcbfunctions/qxcbwindowfunctions.h

@@ -69,6 +69,14 @@ public:
         return QPlatformHeaderHelper::callPlatformFunction<void, SetWmWindowType, QWindow *, WmWindowType>(setWmWindowTypeIdentifier(), window, type);
     }
 
+    typedef void (*SetWmWindowRole)(QWindow *window, const QByteArray &role);
+    static const QByteArray setWmWindowRoleIdentifier() { return QByteArrayLiteral("XcbSetWmWindowRole"); }
+
+    static void setWmWindowRole(QWindow *window, const QByteArray &role)
+    {
+        return QPlatformHeaderHelper::callPlatformFunction<void, SetWmWindowRole, QWindow *, const QByteArray &>(setWmWindowRoleIdentifier(), window, role);
+    }
+
     typedef void (*SetWmWindowIconText)(QWindow *window, const QString &text);
     static const QByteArray setWmWindowIconTextIdentifier() { return QByteArrayLiteral("XcbSetWmWindowIconText"); }
     static void setWmWindowIconText(QWindow *window, const QString &text)

src/plugins/platforms/xcb/qxcbnativeinterface.cpp

@@ -350,6 +350,9 @@ QFunctionPointer QXcbNativeInterface::platformFunction(const QByteArray &functio
     if (function == QXcbWindowFunctions::setWmWindowTypeIdentifier())
         return QFunctionPointer(QXcbWindowFunctions::SetWmWindowType(QXcbWindow::setWmWindowTypeStatic));
 
+    if (function == QXcbWindowFunctions::setWmWindowRoleIdentifier())
+        return QFunctionPointer(QXcbWindowFunctions::SetWmWindowRole(QXcbWindow::setWmWindowRoleStatic));
+
     if (function == QXcbWindowFunctions::setWmWindowIconTextIdentifier())
         return QFunctionPointer(QXcbWindowFunctions::SetWmWindowIconText(QXcbWindow::setWindowIconTextStatic));
 

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -284,6 +284,7 @@ static QWindow *childWindowAt(QWindow *win, const QPoint &p)
 }
 
 static const char *wm_window_type_property_id = "_q_xcb_wm_window_type";
+static const char *wm_window_role_property_id = "_q_xcb_wm_window_role";
 
 QXcbWindow::QXcbWindow(QWindow *window)
     : QPlatformWindow(window)
@@ -610,6 +611,11 @@ void QXcbWindow::create()
         setOpacity(opacity);
     if (window()->isTopLevel())
         setWindowIcon(window()->icon());
+
+    if (window()->dynamicPropertyNames().contains(wm_window_role_property_id)) {
+        QByteArray wmWindowRole = window()->property(wm_window_role_property_id).toByteArray();
+        setWmWindowRole(wmWindowRole);
+    }
 }
 
 QXcbWindow::~QXcbWindow()
@@ -1733,6 +1739,14 @@ void QXcbWindow::setWindowIconTextStatic(QWindow *window, const QString &text)
         static_cast<QXcbWindow *>(window->handle())->setWindowIconText(text);
 }
 
+void QXcbWindow::setWmWindowRoleStatic(QWindow *window, const QByteArray &role)
+{
+    if (window->handle())
+        static_cast<QXcbWindow *>(window->handle())->setWmWindowRole(role);
+    else
+        window->setProperty(wm_window_role_property_id, role);
+}
+
 uint QXcbWindow::visualIdStatic(QWindow *window)
 {
     if (window && window->handle())
@@ -1898,6 +1912,13 @@ void QXcbWindow::setWmWindowType(QXcbWindowFunctions::WmWindowTypes types, Qt::W
     xcb_flush(xcb_connection());
 }
 
+void QXcbWindow::setWmWindowRole(const QByteArray &role)
+{
+    Q_XCB_CALL(xcb_change_property(xcb_connection(), XCB_PROP_MODE_REPLACE, m_window,
+                                   atom(QXcbAtom::WM_WINDOW_ROLE), XCB_ATOM_STRING, 8,
+                                   role.size(), role.constData()));
+}
+
 void QXcbWindow::setParentRelativeBackPixmapStatic(QWindow *window)
 {
     if (window->handle())

src/plugins/platforms/xcb/qxcbwindow.h

@@ -145,10 +145,12 @@ public:
     void updateNetWmUserTime(xcb_timestamp_t timestamp);
 
     static void setWmWindowTypeStatic(QWindow *window, QXcbWindowFunctions::WmWindowTypes windowTypes);
+    static void setWmWindowRoleStatic(QWindow *window, const QByteArray &role);
     static uint visualIdStatic(QWindow *window);
 
     QXcbWindowFunctions::WmWindowTypes wmWindowTypes() const;
     void setWmWindowType(QXcbWindowFunctions::WmWindowTypes types, Qt::WindowFlags flags);
+    void setWmWindowRole(const QByteArray &role);
 
     static void setWindowIconTextStatic(QWindow *window, const QString &text);
 

src/widgets/kernel/qwidget.cpp

@@ -1473,6 +1473,9 @@ void QWidgetPrivate::create_sys(WId window, bool initializeWindow, bool destroyO
 
     data.window_flags = win->flags();
 
+    if (!topData()->role.isNull())
+        QXcbWindowFunctions::setWmWindowRole(win, topData()->role.toLatin1());
+
     QBackingStore *store = q->backingStore();
 
     if (!store) {
@@ -6329,13 +6332,11 @@ QString QWidget::windowRole() const
 */
 void QWidget::setWindowRole(const QString &role)
 {
-#if defined(Q_DEAD_CODE_FROM_QT4_X11)
     Q_D(QWidget);
+    d->createTLExtra();
     d->topData()->role = role;
-    d->setWindowRole();
-#else
-    Q_UNUSED(role)
-#endif
+    if (windowHandle())
+        QXcbWindowFunctions::setWmWindowRole(windowHandle(), role.toLatin1());
 }
 
 /*!