[Fontconfig] Finding a font but without fallback

[Pierre Marchand]

Vous (Keith Packard) avez écrit :
> I hope you realize what a performance cost this is -- fontconfig has
> been designed to cache information about fonts reasonably efficiently;
> on my system with 3382 font files, 'fc-list foo', which reads the entire
> database scanning it for any fonts named 'foo', takes 19ms.

I know how Fontconfig is good in this field and more generally takes care of 
these things. It is just that dealing with uninstalled  fonts, I already had 
a function for scanning directories.  So when someone asked for, at least, 
having the system fonts in "read-only" mode listed in the application 
(without the possibility to deactivate them) I reused the same function.

>
> If fontconfig doesn't provide the interface you need, please build what
> you want and let us see it. We can't fix the library if you continue to
> work around it.

To be honest, I actually think that using Fontconfig the way we do comes to 
pervert  it :-) Though not in how we grab the system fonts list because I do 
it just once at program startup, but rather the way we "activate" fonts (ie 
sym-links into a directory for which we write a DIR element in ~/.fonts.conf) 
and thus we maintain our own database, that’s bad.
But when I tried to base all the activation on Fontconfig by means of 
SELECTFONT, REJECTFONT & ACCEPTFONT I had some issues I could not overcome 
and at this point nobody was interested to help. It’s not a problem since 
we’re at the very beginning of the development and have time to 
refine^^rewrite the code.

Finally, for the moment, the only feature we would want is a font channel on 
DBUS (or something similar) to activate/deactivate, lock/unlock fonts, etc. 
Or is it the only thing I can think at by now? We’ll see!

-- 
Pierre Marchand
http://www.oep-h.com