QGLWidget: Gracefully handle failed makeCurrent during resize and paint event

The underlying QOpenGLContext may fail to be made current, e.g. if the
surface is not exposed, or the graphics hardware is not available.

Instead of trying to initialize and resize the GL viewport with a
non-current context, we return early and defer the init and resize
until later.

Change-Id: I278ca8f1ad4d3da2d5be18b44d775f8d6c8af726
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index 6b4d83888f..ed364283cc 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -145,6 +145,8 @@ public:
             glcx->reset();
     }
 
+    bool makeCurrent();
+
     QGLContext *glcx;
     QGLWidgetGLPaintDevice glDevice;
     bool autoSwap;