Enable access to QWindowsScreen from QScreen

This patch adds access to the QWindowsScreen interface from QScreen with
the aim to provide the native handle of QScreen. This handle will be
used in QtMultmedia to find DXGI interfaces related to that screen.

Change-Id: I93f066b3f0d4d70331aeedab36bb0db111a34556
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/gui/kernel/qplatformscreen_p.h

@@ -20,6 +20,10 @@
 #include <QtCore/qpointer.h>
 #include <QtCore/qnativeinterface.h>
 
+#if defined(Q_OS_WIN32)
+#include <qwindowdefs_win.h>
+#endif
+
 QT_BEGIN_NAMESPACE
 
 class QScreen;
@@ -68,6 +72,14 @@ struct Q_GUI_EXPORT QWebOSScreen
 };
 #endif
 
+#if defined(Q_OS_WIN32) || defined(Q_CLANG_QDOC)
+struct Q_GUI_EXPORT QWindowsScreen
+{
+    QT_DECLARE_NATIVE_INTERFACE(QWindowsScreen, 1, QScreen)
+    virtual HMONITOR handle() const = 0;
+};
+#endif
+
 } // QNativeInterface::Private
 
 QT_END_NAMESPACE

src/gui/kernel/qscreen.cpp

@@ -775,6 +775,10 @@ void *QScreen::resolveInterface(const char *name, int revision) const
     QT_NATIVE_INTERFACE_RETURN_IF(QWebOSScreen, platformScreen);
 #endif
 
+#if defined(Q_OS_WIN32)
+    QT_NATIVE_INTERFACE_RETURN_IF(QWindowsScreen, platformScreen);
+#endif
+
     return nullptr;
 }
 

src/gui/platform/windows/qwindowsnativeinterface.cpp

@@ -8,6 +8,7 @@
 #include <qpa/qplatformintegration.h>
 #include <qpa/qplatformwindow.h>
 #include <qpa/qplatformwindow_p.h>
+#include <qpa/qplatformscreen_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -88,6 +89,15 @@ QOpenGLContext *QNativeInterface::QWGLContext::fromNative(HGLRC context, HWND wi
 
 QT_DEFINE_PRIVATE_NATIVE_INTERFACE(QWindowsApplication);
 
+/*!
+    \class QNativeInterface::Private::QWindowsScreen
+    \since 6.5
+    \internal
+    \brief Native interface to QScreen, to be retrieved from QPlatformIntegration.
+    \inmodule QtGui
+    \ingroup native-interfaces
+*/
+QT_DEFINE_PRIVATE_NATIVE_INTERFACE(QWindowsScreen);
 /*!
     \enum QNativeInterface::Private::QWindowsApplication::TouchWindowTouchType
 

src/plugins/platforms/windows/qwindowsscreen.h

@@ -10,6 +10,7 @@
 #include <QtCore/qpair.h>
 #include <QtCore/qscopedpointer.h>
 #include <qpa/qplatformscreen.h>
+#include <qpa/qplatformscreen_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -38,6 +39,7 @@ struct QWindowsScreenData
 };
 
 class QWindowsScreen : public QPlatformScreen
+                     , public QNativeInterface::Private::QWindowsScreen
 {
 public:
 #ifndef QT_NO_CURSOR
@@ -69,7 +71,7 @@ public:
 
     inline void handleChanges(const QWindowsScreenData &newData);
 
-    HMONITOR handle() const;
+    HMONITOR handle() const override;
 
 #ifndef QT_NO_CURSOR
     QPlatformCursor *cursor() const override { return m_cursor.data(); }