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, 30 insertions, 0 deletions

diff --git a/src/gui/platform/unix/qunixnativeinterface.cpp b/src/gui/platform/unix/qunixnativeinterface.cpp
index 4febe69d91..22bbc555f1 100644
--- a/src/gui/platform/unix/qunixnativeinterface.cpp
+++ b/src/gui/platform/unix/qunixnativeinterface.cpp
@@ -179,6 +179,36 @@ QT_DEFINE_PRIVATE_NATIVE_INTERFACE(QXcbScreen);
 
 QT_DEFINE_PRIVATE_NATIVE_INTERFACE(QXcbWindow);
 
+/*!
+    \class QNativeInterface::QX11Application
+    \since 6.0
+    \brief Native interface to an X11 application.
+
+    Accessed through QGuiApplication::nativeInterface().
+
+    \inmodule QtGui
+    \ingroup native-interfaces
+    \ingroup native-interfaces-qguiapplication
+*/
+
+/*!
+    \fn Display *QNativeInterface::QX11Application::display() const
+
+    \return the X display of the application, for use with Xlib.
+
+    \sa connection()
+*/
+
+/*!
+    \fn xcb_connection_t *QNativeInterface::QX11Application::connection() const
+
+    \return the X connection of the application, for use with XCB.
+
+    \sa display()
+*/
+
+QT_DEFINE_NATIVE_INTERFACE(QX11Application);
+
 #endif // QT_CONFIG(xcb)
 
 #if QT_CONFIG(vsp2)