Avoid extra platformwindows with QQuickWidget

QQuickWidget is nice but does not work on platforms like eglfs
because it always creates a (hidden) platform window for the
QQuickWindow.

This is now fixed by avoiding calling create() on the window and
using the toplevel window of the QQuickWidget instead.

Change-Id: Ia552f7a16d8b913fb798fde04b9304c6d037a46c
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/quick/items/qquickrendercontrol.cpp b/src/quick/items/qquickrendercontrol.cpp
index 7e4335ba63..faee1358ae 100644
--- a/src/quick/items/qquickrendercontrol.cpp
+++ b/src/quick/items/qquickrendercontrol.cpp
@@ -114,9 +114,13 @@ void QQuickRenderControl::initialize(QOpenGLContext *gl)
     Q_D(QQuickRenderControl);
     if (!d->window)
         return;
-    bool current = gl->makeCurrent(d->window);
-    if (current)
-        QQuickWindowPrivate::get(d->window)->context->initialize(gl);
+
+    // It is the caller's responsiblity to make a context/surface current.
+    // It cannot be done here since the surface to use may not be the
+    // surface belonging to window. In fact window may not have a native
+    // window/surface at all.
+
+    QQuickWindowPrivate::get(d->window)->context->initialize(gl);
 }
 
 void QQuickRenderControl::invalidate()