style - Inverted shading with polygons in QGIS 2.8

Is there a way to modify the style of a poygon .shp file so that everything except the polygon is rendered as shaded?

EDIT: see these images if you have trouble understanding. I am going for the effect in the second image.

Answer

Yes.

You just have to do change the style of the polygon from "Single Symbol" to "Inverted polygons".

Here you can see a polygon with a solid fill using the "single symbol" style.

The top left of the style tab in the properties window for the polygon layer is where you change it to "inverted polygons".

Then you can hit OK and see it in the map.

It's fun to experiment with other polygon "simple fills" such as shapeburst.