[RFC] PDA as a TCP graphic tablet?
g.liakhovetski at gmx.de
Sat Dec 24 15:41:38 PST 2005
I have a device (Tuxscreen), capable of running Linux with a
VGA-resolution (I think) LCD display with a touchscreen. So, I had an idea
to use it as a graphic tablet. A quick google revield no existing
software. So, I would just code a server on the device, that would get
events from /dev/eventX, and send them over TCP to a PC, where a client
would just export, say, a named pipe, which X would open as a device node.
That's all nice and simple, now, I don't know how best to present this
device to X. The touchscreen can deliver only x, y, and pressure. The
device has a keyboard, so, I can switch between, say, those 3 modes that
wacom tablets use (stylus, eraser, cursor)? Don't think many have
Tuxscreens, but a possibility to use any Linux PDA as a graphic tablet
(ok, pretty poor, but still) would be interesting to many?
So, what is the sensible way to bind to X? I would prefer not to have to
write a new X-driver... Abusing the wacom driver would be dirty... I see a
number of drivers in input/, but have no idea if one of them would be
suitable for that. Don't think evdev would do? As an application I am
thinking about Gimp.
If there is already a driver I could reasonable (ab)use, ideally it should
only use read/write on the fd. If it uses ioctl's, well, that would mean I
would have to write a kernel driver too. Not too dramatic, but not exactly
the ideal solution.
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