Export rootWindow to the QXcbNativeInterface

This change exports the root window to the native interface as there
is QX11Info::appRootWindow which so far goes over the QDesktopWidget
to get the window id of the root window. Which is a rather hackish way
considering that the root window is known to the QXcbConnection.

But even more it's a very fragile way and can result in crashes on
startup of applications if the application accesses the appRootWindow
too early.

Change-Id: Ibb09a7fa714cb355f579298fc6df33bf80f73f58
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: David Faure <david.faure@kdab.com>
Reviewed-by: Gatis Paeglis <gatis.paeglis@digia.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/plugins/platforms/xcb/qxcbnativeinterface.h b/src/plugins/platforms/xcb/qxcbnativeinterface.h
index 9c4fa44d3b..fb1a46014c 100644
--- a/src/plugins/platforms/xcb/qxcbnativeinterface.h
+++ b/src/plugins/platforms/xcb/qxcbnativeinterface.h
@@ -70,7 +70,8 @@ public:
         StartupId,
         TrayWindow,
         GetTimestamp,
-        X11Screen
+        X11Screen,
+        RootWindow
     };
 
     QXcbNativeInterface();
@@ -94,6 +95,7 @@ public:
     void *getTimestamp(const QXcbScreen *screen);
     void *startupId();
     void *x11Screen();
+    void *rootWindow();
     static void setAppTime(QScreen *screen, xcb_timestamp_t time);
     static void setAppUserTime(QScreen *screen, xcb_timestamp_t time);
     static void *eglContextForContext(QOpenGLContext *context);