Re: master 3b41141708: Expose the name of an event's input device to Lisp

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 09 Apr 2022 20:06:00 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: luangruo@yahoo.com, emacs-devel@gnu.org, monnier@iro.umontreal.ca,
>  rms@gnu.org
> 
> > From: Lars Ingebrigtsen <larsi@gnus.org>
> > Cc: Eli Zaretskii <eliz@gnu.org>,  Po Lu <luangruo@yahoo.com>,  Richard
> >  Stallman <rms@gnu.org>,  emacs-devel@gnu.org
> > Date: Sat, 09 Apr 2022 18:41:52 +0200
> > 
> > For instance, I have a pedal that's a USB HID thingie.  Amusingly
> > enough, stomping on the pedal gives me a "b" event.  The key "b",
> > indistinguishable from a "b" from the keyboard.
> > 
> > So if I could somehow say
> > 
> > (keymap-set global-mode-map "[device footpad]-b" 'do-something)
> > 
> > that would be ideal.
> 
> I would hope that such an event could be called just 'footpad-b', so
> that any device capable of such events could be implemented as
> emitting it, regardless of the device name/type/etc.

Actually, '[footpad b] would even be better, i.e. a key sequence that
consists of 'footpad; followed by 'b'.  This way we will be able to
express many possible keys produced by such devices using just one
prefix key.