Image get blurred if scrolled

[KKyang]

Image get blurred if scrolled.

Error occurs when QGLWidget is set.

https://github.com/KKyang/qtsmartgraphics/blob/master/qsmartgraphicsview.cpp#L27

[KKyang]

If a stylesheet is set. The QGLWidget will fail to update.

http://stackoverflow.com/questions/31658176/using-qopenglwidget-with-qgraphicsview-viewport-not-updating

Temporarily fix:

Remove the line mention above.

or

Remove the stylesheet.