[9fans] scrollbuttons 2.0

[andrey mirtchovski <mirtchov@cpsc.ucalgary.ca>]

this is my mouse (well, a latter iteration of it, actually):

	http://www-132.ibm.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=-840&langId=-1&partNumber=31P8700&storeId=1

the blue thing at the middle is a scroll button named ScrollPoint.
it's not a scroll wheel and resembles the cat tongue found on ibm
laptops.  i find myself using it more and more in X and lacking the
functionality in Plan 9.  to aleviate the problem i've implemented a
very simple change (hack?) to drawterm to make it use the ScrollPoint.

ScrollPoint works by sending 'Button 4' and 'Button 5' press/release X
events whenever it is pushed up or down.  drawterm now knows about
those two buttons and whenever it sees those events it sends a Kup and
Kdown keyboard commands to Plan 9.  it's strange that way, but it
actually works out amazingly well for terminals, acme and everything
else, even for vnc sessions initiated from Plan 9 (i run drawterm
fullscreen on lunux and then vnc back to the same box to get a browser
in my Plan 9 window).

the only problem i've seen so far with it is that pressing the button
in X terminals causes the bash history to appear (Kup) instead of a
scroll (Kpgup).  i could change Kup → Kpgup and Kdown → Kpgdown but
then the scrolling in Plan 9 would be much faster and imprecise...

because i don't have any other wheel mice around here i'd like to ask
those of you who are interested to give it a try to download the
drawterm-linux.gz and drawterm-freebsd.gz clients from
http://pages.cpsc.ucalgary.ca/~mirtchov/p9/ and see if their scroll
buttons work with them.  if you can compile drawterms for MacOSX,
Windows and your favuorite other OS i'd gladly put them on my page.
the source is in the same location -- drawterm.tgz.

i'd also like to ask for suggestions on how to implement it natively
in Plan 9.  the 'send keyboard command instead of a mouse event'
requires very little change, but is it 9-ish enough?

andrey