Hi,
being a ctwm user for exactly 20 years this month, I made myself a little
anniversary present digging further into ctwms not-so-well-known features.
Indeed, I stumbled over this by chance, but I like it so much that I though
it might be useful for other users, too.
So here's a little use case for ctwms "alternate context". I used to run xmms
for listening mp3s with my headphones when the familiy is sleeping, and I
lay myself on the couch, turn of the screen and blindly control volume and
forward/backward only with the arrow keys.
That worked fine with xmms, but now that I had to switch to qmmp, it turned
out that qmmp inc/dec the volume by 5 (hard coded), and together with the
strange pulseaudio interference, the volume jumps up and down by more
than 10%. No fine-grained control possible.
So I finally ended up with ctwm taking control over the arrow keys and
setting volume by my own commands whenever I use qmmp. Here's how to
do that:
### Begin
# start my "music mode" with f8:
"F8" = :all : f.function "tft_xmms"
Function "tft_xmms" {
# raise qmmp and give it the focus
f.exec "HOME/bin/goto_qmmp"
# turn off the screen
f.exec "/usr/bin/tft off"
# turn on alternativ key map
f.altcontext
}
# Now define what certain keys should do in "alternate context"
# Note: any other key will leave the context
"Up" = :alter : f.function "up"
"Down" = :alter : f.function "down"
"Left" = :alter : f.function "left"
"Right" = :alter : f.function "right"
# turn screen on again. Note: this disables the alternate context as we
# don't activate it again.
"F9" = :alter : f.exec "usr/bin/tft on"
# If we left alternate context already by some other keypress, we
# need the "normal" F9, too:
"F9" = :all : f.exec "usr/bin/tft on"
# raise volume by 1, and VERY IMPORTANT: stay in the alternate context
Function "up" { f.exec "aumix -v +1" f.altcontext }
# Same for the other functions:
Function "down" { f.exec "aumix -v -1" f.altcontext }
Function "right" { f.exec "qmmp --seek-fwd 10" f.altcontext }
Function "left" { f.exec "qmmp --seek-bwd 10" f.altcontext }
### End
Thus, when I press F8 I get focus on the qmmp window and as long as
I only use the four arrow keys, I will always stay in the alternate
context, and ctwm will not send the keystrokes to qmmp but handle
them itself. The moment I press any other key, I'm back to the normal
mode.
Note that with f.altkeymap one can even define several keymaps and
explicitely chose which one to use.
I really like the idea of temporarily withdrawing control from a
program and letting ctwm handle certain keys, and I guess I will
find some other useful scenarios now that I stark thinking about it :-)
Have fun!
cu,
Frank
--
Dipl.-Inform. Frank Steiner Web: http://www.bio.ifi.lmu.de/~steiner/
Lehrstuhl f. Bioinformatik Mail: http://www.bio.ifi.lmu.de/~steiner/m/
LMU, Amalienstr. 17 Phone: +49 89 2180-4049
80333 Muenchen, Germany Fax: +49 89 2180-99-4049
* Rekursion kann man erst verstehen, wenn man Rekursion verstanden hat. *
