Add platform native interface to offscreen plugin

Adds trival support for querying "display" and "glxconfig" in case
offscreen plugin is compiled with xlib support.

This is required so this plugin could work with webengine.

Taks-number: QTBUG-63346
Change-Id: Ie0f29385cb44429ddf383ad459e0c9f3263ccffe
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

3 files changed, 62 insertions, 25 deletions

diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration.h b/src/plugins/platforms/offscreen/qoffscreenintegration.h
index fc988126bb..098e726550 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration.h
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration.h
@@ -41,6 +41,7 @@
 #define QOFFSCREENINTEGRATION_H
 
 #include <qpa/qplatformintegration.h>
+#include <qpa/qplatformnativeinterface.h>
 
 #include <qscopedpointer.h>
 
diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
index 93566220e8..06a9bd2a4c 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.cpp
@@ -52,6 +52,30 @@
 
 QT_BEGIN_NAMESPACE
 
+class QOffscreenX11Info
+{
+public:
+    QOffscreenX11Info(QOffscreenX11Connection *connection)
+        : m_connection(connection)
+    {
+    }
+
+    Display *display() const {
+        return (Display *)m_connection->display();
+    }
+
+    Window root() const {
+        return DefaultRootWindow(display());
+    }
+
+    int screenNumber() const {
+        return m_connection->screenNumber();
+    }
+
+private:
+    QOffscreenX11Connection *m_connection;
+};
+
 QOffscreenIntegration *QOffscreenIntegration::createOffscreenIntegration()
 {
     return new QOffscreenX11Integration;
@@ -77,6 +101,35 @@ QPlatformOpenGLContext *QOffscreenX11Integration::createPlatformOpenGLContext(QO
     return new QOffscreenX11GLXContext(m_connection->x11Info(), context);
 }
 
+QPlatformNativeInterface *QOffscreenX11Integration::nativeInterface() const
+{
+   return const_cast<QOffscreenX11Integration *>(this);
+}
+
+void *QOffscreenX11Integration::nativeResourceForScreen(const QByteArray &resource, QScreen *screen)
+{
+    Q_UNUSED(screen)
+    if (resource.toLower() == QByteArrayLiteral("display") ) {
+        if (!m_connection)
+            m_connection.reset(new QOffscreenX11Connection);
+        return m_connection->display();
+    }
+    return nullptr;
+}
+
+#ifndef QT_NO_OPENGL
+void *QOffscreenX11Integration::nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context) {
+    if (resource.toLower() == QByteArrayLiteral("glxconfig") ) {
+        if (!m_connection)
+            m_connection.reset(new QOffscreenX11Connection);
+        QOffscreenX11Info *x11 = m_connection->x11Info();
+        GLXFBConfig config = qglx_findConfig(x11->display(), x11->screenNumber(), context->format());
+        return config;
+    }
+    return nullptr;
+}
+#endif
+
 QOffscreenX11Connection::QOffscreenX11Connection()
 {
     XInitThreads();
@@ -93,30 +146,6 @@ QOffscreenX11Connection::~QOffscreenX11Connection()
         XCloseDisplay((Display *)m_display);
 }
 
-class QOffscreenX11Info
-{
-public:
-    QOffscreenX11Info(QOffscreenX11Connection *connection)
-        : m_connection(connection)
-    {
-    }
-
-    Display *display() const {
-        return (Display *)m_connection->display();
-    }
-
-    Window root() const {
-        return DefaultRootWindow(display());
-    }
-
-    int screenNumber() const {
-        return m_connection->screenNumber();
-    }
-
-private:
-    QOffscreenX11Connection *m_connection;
-};
-
 QOffscreenX11Info *QOffscreenX11Connection::x11Info()
 {
     if (!m_x11Info)
diff --git a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
index 5e1c6b799b..a1986fdc94 100644
--- a/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
+++ b/src/plugins/platforms/offscreen/qoffscreenintegration_x11.h
@@ -52,12 +52,19 @@ QT_BEGIN_NAMESPACE
 class QOffscreenX11Connection;
 class QOffscreenX11Info;
 
-class QOffscreenX11Integration : public QOffscreenIntegration
+class QOffscreenX11Integration : public QOffscreenIntegration,  public QPlatformNativeInterface
 {
 public:
     bool hasCapability(QPlatformIntegration::Capability cap) const override;
 
     QPlatformOpenGLContext *createPlatformOpenGLContext(QOpenGLContext *context) const override;
+    QPlatformNativeInterface *nativeInterface()const override;
+
+    // QPlatformNativeInterface
+    void *nativeResourceForScreen(const QByteArray &resource, QScreen *screen) override;
+#ifndef QT_NO_OPENGL
+    void *nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context) override;
+#endif
 
 private:
     mutable QScopedPointer<QOffscreenX11Connection> m_connection;