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RE: General Input Model

From: Leonard R. Kasday <kasday@acm.org>
Date: Fri, 14 Apr 2000 11:00:57 -0400
Message-Id: <>
To: Charles McCathieNevile <charles@w3.org>, Bruce Bailey <bbailey@clark.net>
Cc: w3c-wai-ig@w3.org, asgilman@iamdigex.net
I'm glad to hear there's a chance for a more general input model in XHTML 2.0.

A few thoughts...

There are lots of input devices commecially available today that go beyond 
the mouse and keyboard model.  For example, game controllers crawling with 
buttons; or spatial input devices, used in virtual reality, that can sense 
position and orientation (x, y, z, pitch, roll, yaw).  And still more that 
never got beyond the research stage (e.g. a touch screen I developed a 
while back that sensed normal and shear components of any number of 
simultaneously applied forces).

We want to maximize the opportunity to provide accessible alternative 
inputs. So a general input model should support, at a minimum,

1. an arbitrary number of input devices

2. each device can send events and status for zero or more discrete 
variables and zero or more continuous variables

3. at any time, a given input device I can send events to any user 
interface object O (e.g. field, menu, 3D lever, etc); we then say that that 
O has focus from I .

4. The software may respond to the events and status information in (2), 
and acquisition or loss of focus described in (3).

5. Software "event transformations" would be available to change events 
from one or more input devices to the equivalent of events from any other 
device.  (This is a generalization of "serial keys" and
"mouse keys").

This would give us the maximum chance to provide an alternative 
inputs.  (Plus it's just plain good software engineering I think).



A more general approach would be to bypass the normal inputs and go 
directly to the underlying data but that's beyond this the scope of this 

At 09:33 AM 4/14/00 -0400, Charles McCathieNevile wrote:
>There will be development of HTML as XHTML 2.0, and there is an opportunity
>to improve things. The implementation of the Docment Object Model
>(DOM) specifiation could also lead to a big improvement, as the Web moves
>from just HTML to more and richer XML.
>Charles McCN
>On Mon, 10 Apr 2000, Bruce Bailey wrote:
>   Dear Len,
>   I think you are correct.  I guess that is part of what I am rebelling
>   against:  that rather than being "device independent/neutral", focus really
>   has been defined to mean "keyboard focus".  This is a shame.  Is it
>   unrealistic to hope that if there is an HTML 4.02 (I am guessing that there
>   will NOT be) that this would get corrected?

Leonard R. Kasday, Ph.D.
Institute on Disabilities/UAP, and
Department of Electrical Engineering
Temple University
423 Ritter Annex, Philadelphia, PA 19122


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Received on Friday, 14 April 2000 11:00:23 UTC

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