[Xgl/Xegl] Input Devices
Dane Rushton
danerushton at gmail.com
Tue Jul 19 00:59:52 PDT 2005
Hi All,
I'm going to have ago at developing the input subsystem for Xegl, and
possible for other X's.
I'm in the early research/requirements gathering stage, so I'm after
some input from the experts and your thoughts on the likely direction of
input drivers in Linux and other Unix-like OS's.
I know Jon Smirl has put together a basic system using EVDEV for Xegl.
The Event Interface (EVDEV) is quite new to Linux, and may not be
available in other OS's, so is it worth using? Or should it be one of
several options?
Xegl is aimed at a Free Desktop that is user friendly and feature rich,
so most things should "Just Work (tm)" without any configuration except
when the user is trying to do something advanced.
The core requirements, as I see them are:
1) Auto-detect devices attached prior to X server initialisation.
No config files for basic stuff!
2) Auto-detect devices added or removed during X server run-time.
The HAL system available on Linux would be excellent for this,
but again it isn't available for other systems yet.
What are people's thoughts on utilizing technologies such as
HAL?
3) Most workstations and home PC's will want all pointing devices
to be combined into a common input. For example a laptop with an
integrated touchpad and an attached USB mouse.
The default setting should be to detect all pointing devices at
startup (and any changes during execution) and just use them.
Linux currently has a /dev/input/mice node which combines
/dev/input/mouse* devices, but that isn't available in EVDEV
(as far as I know) if we go that way.
4) The same should occur for keyboards or other similar devices.
Examples are laptops with external keyboards, barcode scanners,
left-handed number pads etc.
5) For advanced situations the user may have multiple X server
instances running, each with their own screen, keyboard and
mouse. This situation is less likely, and would be okay to
require manual configuration. In that situation the server will
take a list of which devices it can use. I don't know what
should happen when devices are added at runtime, i.e. which
server should get it etc.
Additions, corrections, comments and general discussion welcome.
Cheers
Dane Rushton
More information about the xorg
mailing list