[FOSS-GPS] FoxtrotGPS paint-optimize branch

[John Stowers]

> 
> Oh, and two more things:
> 
> The widget seems to use alpha blending quite a lot. This probably won't fly well on the 
> freerunner with its limited gfx bandwidth. Is there a way to toggle certain performance 
> impacting settings?

There is currently no way to toggle such optimizations. I would want to
see some sort of benchmark to suggest that the alpha component of the
drawing is causing some measurable slowdown before considering this.

> And finally, I think the tile downloading code should be externalized. A widget should not 
> introduce a dependency on a http fetcher. Of course you can offer the current downloading 
> code as an extra module which you can plug in, but the application should be allowed to 
> replace that with its own downloader. So basically that would introduce a 
> 'request_tile_url' callback, and a 'tile_ready' function to signal the availability of the 
> new tile.

I'm not a fan of this idea sorry. IMO osm-gps-map should be 
 * "batteries included"
 * a good GObject/Gtk+ citizen

I dont think thaqt suggestion is aligned with these goals.

Cheers,

John