[cairo] Not updating screen

[Jose Hevia]

> If your windowing system / whatever doesn't provide double-buffering,
> cairo has the notion of "groups" that you can use for that.
>
> See
>
>   http://cairographics.org/manual/cairo-cairo-t.html#cairo-push-group
> for more information.

Thanks, that is what I was looking for :-) .

I don't want to use low level suff (windowing system) in this project.