QOpenGLWidget in QGraphicsView causes various graphical issues.

When using a QOpenGLWidget as viewport in a QGraphicsView I noticed a number of issues:

When resizing the widget (using the mouse), the view goes blank and does not repaint until another action is performed which would trigger a repaint (such as moving the scrollbars).

The background color is now black (with default viewport, it's white).

Going to fullscreen will prevent the context menu from popping up. The menu will still work as clicking where the items should appear will still trigger the correct action.

Going from full screen back to windowed view will often cause text rendering to break. The text will become a bunch of opaque boxes. When going back to full screen, the text is restored.

All problems can reproduced using the application provided.

None of these issues occur if you comment out line 82 of MyDisplay.cpp (m_view->setViewport(new QOpenGLWidget()); ).