[BRLTTY] [OT] How to integrate BSI into a Linux cell phone?

[Mario Lang]

Rich <rdm at cfcl.com> writes:

> I'm a sighted, semi-retired, volunteer developer who is very interested in the
> possibility of re-purposing Android cell phones as blind-accessible computing
> and communication devices.  There are a number of projects working on re-using
> the billions of aging cell phones that are out there.  Some, such as LineageOS,
> start with an open source version of Android.  Others, such as postmarketOS and
> Mobian, start with a more vanilla flavor of Linux (e.g., Alpine, Debian).
>
> Although the first approach makes tons of Android software available, most of
> this is GUI-based, so accessibility will generally be a challenge.  Basing the
> system on Linux allows a wealth of CLI-based software to be used and helps to
> anchor the resulting system more closely in the open source community.

I can follow your analysis.  I dont agree with some of its conclusions,
but lets continue.

> Challenges
>
> One of the biggest challenges, I suspect, will be providing an accessible form
> of text input.  Most screen-based keyboards for cell phones aren't suitable,
> a physical keyboard would add cost and bulk, and voice recognition (without the
> support of cloud computing) still seems to be beyond the phone's capabilities.

Voice Recognition also conflicts with your idea of a CLI-based system.
A physical keyboard doesn't sound like a real problem.
However, if you want to aim for a completely mobile solution, BSI as you
call it seems like the best option around.

> So, I've been speculating about how to support Braille Screen Input (BSI) on a
> Linux-based cell phone.  BSI is available on Android, Fire OS, and iOS (please
> let me know if I'm missing any others!), but I haven't found any indication that
> anyone is working on supporting it for any form of Linux.

I guess the reason for that is that plain Linux systems running on a
worn-out mobile device aren't really populare amongst blind users.
Cost-wise, Rasperry Pis are very much more populare when it comes to
building a low-cost computing solution.  Adding a USB keyboard doesnt
really drive up the cost, and is very easy to do.  If you dont
care for high performance applications, as a blind user, you're
basically done now.  There is no real need for a monitor, for instance.

> I think I have a handle on how to architect the front end of the code, using a
> set of Actors (lightweight processes) running on a foundation of Elixir, Erlang,
> and OTP.

Are you saying you want to implement the motion tracking for the
multitouch screen with the stack you mention above?  Or do you plan to
write your applications with that stack?

> However, I'm totally out of my depth when it comes to interfacing the
> code to other apps, the window system, and the rest of the OS.

You seem to be contradicting yourself.  At the beginning, you argue that
a plain Linux system is better because it doesn't have a GUI.  Now, you
are looking for ways to interface wtih a windowing system.  I am
confused.

> Should I be looking into D-Bus, GTK, Qt, or what?

That really depends on what sort of applications you are trying to
support on your system.  If I wanted to write a BSI for CLI on Linux,
I'd be looking into the Linux kernel input device API.  You can simulate
a keyboard in software with that.  How you talk to your multitouch
screen devices is totally out of my knowledge.

> Also, are there any ways the code could leverage BRLTTY, Emacspeak,
> Orca, etc?  How would typical blind users want a BSI subsystem to act
> in this context?  I'm really confused here, so I'm asking for advice,
> comments, and so forth.

Frankly, you dont quite understand the ecosystem you are trying to
adapt.  Orca is only relevant if you decide to go for a GUI based
system.  Emacspeak is pretty specific to Emacs users, although I guess
it could be used as the main audio desktop if you want to go that way.
BRLTTY should be easy to plug in, if you are either using virtual
terminals or something that requires Orca.

>
> -r
>
> P.S.  There is at least one physical keyboard which isn't totally out of the
> question for use with a cell phone.

I am pretty sure there are more then just one.

-- 
AR Mario Lang                               Phone: +43 316 873 6897
Graz University of Technology              Mobile: +43 664 60 873 6897
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