Add native interface for X11 application, exposing display and connection

The major use-case of the now private QX11Info from Qt X11 Extras was
getting hold of the Xlib display and XCB connection, for example in KDE:

  https://lxr.kde.org/search?%21v=kf5-qt5&_filestring=&_string=QX11Info

A new native interface for QGuiApplication has now been added that
exposes these two properties, e.g.:

  if (auto *x11App = app.nativeInterface<QX11Application>())
      qDebug() << x11App->display() << x11App->connection();

To avoid type clashes one of the enum values of QXcbNativeInterface's
ResourceType had to be renamed.

Pick-to: 6.2
Task-number: QTBUG-93633
Change-Id: I2e366a2bb88bd3965ac6172ad000ae32209f43e7
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 8 insertions, 3 deletions

diff --git a/src/plugins/platforms/xcb/qxcbnativeinterface.h b/src/plugins/platforms/xcb/qxcbnativeinterface.h
index 4656f46be5..5508d57679 100644
--- a/src/plugins/platforms/xcb/qxcbnativeinterface.h
+++ b/src/plugins/platforms/xcb/qxcbnativeinterface.h
@@ -45,6 +45,8 @@
 
 #include <QtCore/QRect>
 
+#include <QtGui/qguiapplication.h>
+
 #include "qxcbexport.h"
 #include "qxcbconnection.h"
 
@@ -54,11 +56,12 @@ class QXcbScreen;
 class QXcbNativeInterfaceHandler;
 
 class Q_XCB_EXPORT QXcbNativeInterface : public QPlatformNativeInterface
+    , public QNativeInterface::QX11Application
 {
     Q_OBJECT
 public:
     enum ResourceType {
-        Display,
+        XDisplay,
         Connection,
         Screen,
         AppTime,
@@ -109,9 +112,11 @@ public:
     void *startupId();
     void *x11Screen();
     void *rootWindow();
-    void *display();
+
+    Display *display() const override;
+    xcb_connection_t *connection() const override;
+
     void *atspiBus();
-    void *connection();
     static void setStartupId(const char *);
     static void setAppTime(QScreen *screen, xcb_timestamp_t time);
     static void setAppUserTime(QScreen *screen, xcb_timestamp_t time);