Keyboard re-mapping
McSwell
Windows, which allows me to map control keys (actually, the caps-lock
+ alphabetic keys) to cursor control keys. For instance, ^H is left
one character (= left arrow), ^J down one line (= down arrow), ^W
forward one word (= control right arrow), and so forth. My Windows
remapping program is written in C, compiles to an exe and a dll,
intercepts the keystrokes at the system level using an OS hook, and
outputs the desired cursor keys.
Some of this remapping I've been able to do in Linux (Ubuntu) using
xkb. However, there are a number of things that I haven't been able
to figure out how to do, and which it appears to me are in fact not
possible using xkb. I'm hoping someone will prove me wrong!
One limitation of xkb is that, AFAICT, xkb limits the output to one
keystroke per input keystroke. While the mappings listed above are
one-to-one (and I have them working under xkb), several of my mappings
are one-to-many. For example, ^D outputs seven down arrow keystrokes,
and ^U outputs seven up arrow keystrokes. Now several of the xkb
compatibility map functions have a 'count' parameter, including
DeviceButton. But the RedirectKey() function does not. I have
thought about using DeviceButton() mapped to an imaginary device to
produce seven imaginary button presses, and then mapping each of those
button presses back to a keystroke--but if it's possible for xkb to
use as input its own output, I don't know how to do that. Nor can I
figure out a work-around; it does not appear possible to simply
include more than one key as an arg to RedirectKey(), nor to include
RedirectKey() more than once for any given keystroke combination. (In
the case of my ^D and ^U, the output is seven identical keystrokes. I
have a few keystroke mappings where the output should be a sequence of
distinct keystrokes.)
I also can't figure out how to persuade xkb to output as control
characters those <capslock> keystrokes that I don't want changed,
other than converting the <capslock> to a <control> key. For example,
I want <capslock>s to produce a <control>s. It appears to me that xkb
refuses to do this kind of mapping where the input alphabetic
keystroke is the same as the output alphabetic keystroke: I can map
<capslock>s to <control>f, but not to <control>s. I suspect that if I
*always* wanted to do this, it would be trivial with xkb: I would just
map the <capslock> key to a <control> key. The problem is that I
*don't* always want to do that, in particular I don't want to do it
where I map a <capslock> key to a cursor key.
There are a couple other potentially tricky mappings which I haven't
tried yet, because unless I could fix the above problems, there was no
sense in figuring out how to do these. But maybe I just haven't
interpreted the documentation for xkb correctly, and someone will tell
me the problems sketched above are simple to fix.
Alternatively, maybe I would be better off writing my own keyboard
driver in C. I haven't tried that, because I'm not sure where I would
start, nor do I know how I would use such a driver if I did write it.
(Do you create a shared object library, like my Windows remapper? Or
does the driver get loaded some other way?)
So my question is, are there solutions in xkb to the problems I've
sketched above? Specifically the inability to output > 1 keystroke
per input keystroke, and the problem of mapping some (but not all)
<capslock><alpha> keystrokes to <control><alpha> keystrokes?
I can upload my xkb file if that would help.
BTW, here is some of the documentation I've found for xkb:
pascal.tsu.ru/en/xkb/
http://hektor.umcs.lublin.pl/~mikosmul/computing/articles/custom-keyboard-layouts-xkb.html
http://www.charvolant.org/~doug/xkb/
http://www.xfree86.org/current/XKBproto.pdf
Mike Maxwell
Wanna-Be Sys Admin
> I have for years used a home-made keyboard remapping program under
> Windows, which allows me to map control keys (actually, the caps-lock
> + alphabetic keys) to cursor control keys.
Try seeking help in comp.os.linux.development.system Very, very little
spam and real posts about this sort of thing.
--
Not really a wanna-be, but I don't know everything.
McSwell
> Try seeking help in comp.os.linux.development.system Very, very little
> spam and real posts about this sort of thing.
Thanks, will do!
> Not really a wanna-be, but I don't know everything.
Well, you knew something I didn't know :-!
HASM
> For instance, ^H is left one character (= left arrow), ^J down one line
> (= down arrow), ^W forward one word (= control right arrow), and so
> forth.
> For example, ^D outputs seven down arrow keystrokes, and ^U outputs seven
> up arrow keystrokes.
Looks like it would be simpler to switch to emacs/xemacs :-)
-- HASM