eglfs: Implement nativeResourceForWindow

Add support to request EglDisplay resource for a window. This is
supported in other platform plugins, like kms and xcb and is required by
wayland-egl based QtWayland compositors.

Change-Id: If3f8c625682915c9671e820974e810763c3c8b66
Reviewed-by: Andy Nichols <andy.nichols@digia.com>

src/plugins/platforms/eglfs/qeglfsintegration.cpp

@@ -202,6 +202,20 @@ void *QEglFSIntegration::nativeResourceForIntegration(const QByteArray &resource
     return 0;
 }
 
+void *QEglFSIntegration::nativeResourceForWindow(const QByteArray &resource, QWindow *window)
+{
+    QByteArray lowerCaseResource = resource.toLower();
+
+    if (lowerCaseResource == "egldisplay") {
+        if (window)
+            return static_cast<QEglFSScreen *>(window->handle()->screen())->display();
+        else
+            return static_cast<QEglFSScreen *>(mScreen)->display();
+    }
+
+    return 0;
+}
+
 void *QEglFSIntegration::nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context)
 {
     QByteArray lowerCaseResource = resource.toLower();

src/plugins/platforms/eglfs/qeglfsintegration.h

@@ -72,6 +72,7 @@ public:
 
     // QPlatformNativeInterface
     void *nativeResourceForIntegration(const QByteArray &resource);
+    void *nativeResourceForWindow(const QByteArray &resource, QWindow *window) Q_DECL_OVERRIDE;
     void *nativeResourceForContext(const QByteArray &resource, QOpenGLContext *context);
 
     NativeResourceForContextFunction nativeResourceFunctionForContext(const QByteArray &resource) Q_DECL_OVERRIDE;