[BRLTTY] make drivers a library?

[Samuel Thibault]

Nicolas Pitre, le Tue 22 Sep 2009 13:32:40 -0400, a écrit :
> On Tue, 22 Sep 2009, Samuel Thibault wrote:
> > Yet another person on the NVDA list wanted to re-implement a driver for
> > some braille device because he doesn't want to have to run both brltty
> > and nvda at the same time.

Various reasons such as additionally mentioned in my other post
http://mielke.cc/pipermail/brltty/2009-September/006118.html
having to deal with starting/stopping two daemons at a time.

> > Of course, it's a better thing to use the brlapi facility as this
> > permits to run several readers, dedicated applications, etc. but for
> > the casual user this seems superfluous considering the difficulty of
> > installing both brltty and nvda (yes, I believe we got to a very simple
> > way to achieve that, but two applications is still too much for casual
> > users).
> 
> I don't buy that for a minute.  Windows has plenty of installer kits to 
> chose from, making all the underlying 
> programs/services/components/whatnot bundled and installed together with 
> no distinction unless the user really wants to dig.  Most games will 
> package DirectX and install it unless there is already a newer version 
> installed already for example.

Yes, but they don't start a service that may completely steal the screen
output and interfere with the VGA driver just because one has opened a
command line window, which is equivalent to what currently happens after
having installed brltty while jaws is installed.

> Also, if NVDA relies on BRLTTY to work properly then it should ensure 
> BRLTTY is running and start it otherwise, all by itself.  This is not 
> rocket science.

Ok, and when shutting down NVDA, should it shut down BRLTTY?  What if it
just happened that NVDA got started before the proper script that was
supposed to start BRLTTY once for good got a chance to run?

> > As a result, I yet more and more believe that brltty should export its
> > drivers through a library too, even with an simple interface similar
> > to libbrlapi/libbraille.
> 
> Are they thinking the same about the Windows speech API?

The windows speech API doesn't pose access to sound card issues and
interference with jaws & co like access to braille devices do.

> > Else I fear dispersion of hardware support
> > efforts.
> 
> If the effort needed to make proper integration of BRLTTY/BRLAPI for a 
> better NVDA user experience is greater than plain driver duplication, 
> then I'm afraid that making a proper library interface would be an even 
> greater effort (except that the effort is now shifted to BRLTTY 
> developers instead).

I'd rather see better integration too, but up to now that hasn't been
a success, while I can see how BRLTTY could manage to externalise its
drivers, and as I said in the other post it could be useful for other
cases too like grub or other kind of embedding on small devices which
can't afford local sockets and threads just for BrlAPI.

> > What do people think?
> 
> I think this is the wrong solution for a valid issue.

Usual answer from you :)

Samuel