The key point in my mind is that the
nature of the problem ("a risk of causing an epileptic fit")
may raise this from an accessibility issue to a safety issue.
ISO Directives, Part 2, section A.2.3
gives the following guidance:
"A.2.3 If health, safety aspects,
the protection of the environment or the economical use of
resources are relevant to the product,
appropriate requirements shall be included. Otherwise,
they may, in some countries, be made
additional mandatory requirements which, if not
harmonized, would constitute technical
barriers to trade.
These requirements may need to have
certain characteristics with limiting values (maximum
and/or minimum) or closely defined sizes
and, in some cases, even constructional stipulations
(for example, to achieve non-interchangeability
for safety reasons). The levels at which these
limits are fixed shall be such that
the element of risk is reduced as much as practicable."
So I think we should make some statement
in the standard itself, not merely in a separate guidelines document,
that defines how to use this feature safely.
Which leads me to the technical questions:
1) Surely, the table refresh itself
is inoffensive, right? For example, an application could have a table
refresh (fetch new data) but only display updates when some other condition
was met. Or you might not have any GUI at all and the updates and
recalc's trigger some action on the server.
2) Is any screen update faster than
once every 3 seconds a problem? Or is it only certain styles of updates,
the ones which noticeably "flash" because of poor redrawing,
lack of double buffering or whatever? In other words is there any
safe way of doing rapid screen updates?
3) Most display technologies are already
redrawing at a fast rate. This is inherent in the graphics card/display
technology. So very fast rates are OK? What is the range of
rates where it is a problem?
4) How do we state this in the standard?
Would something like this work: "Note: display devices
which update information on the screen at rates between X Hz and Y Hz have
been shown to prompt epileptic seizures in some people. ODF applications
which refresh the display with each table refresh shall provide an option
for the user to suspend the rendering of such refreshes." We
could probably make a more general statement on refresh/animation/blink
and place it in the conformance section of the standard.
-Rob
Duane Nickull <dnickull@adobe.com> wrote on
07/18/2008 02:12:38 PM:
>
> The main point is that implementors have control when implementing
> the specification vs. being constrained by the spec. Let’s
not put
> weightless restrictions into the specification.
>
> Duane
>
>
> On 18/07/08 10:35 AM, "Peter Korn" <Peter.Korn@Sun.COM>
wrote:
> Hi Dave,
>
> In OpenOffice.org we have the ability to turn animation off.
I
> agree with Malte; we shouldn't prevent the expression of fast
> animation for those who want it, but we should enable users to not
> have it displayed to them.
>
>
> Regards,
>
> Peter Korn
> Accessibility Architect,
> Sun Microsystems, Inc.
>
> 2008/7/18 Malte Timmermann <Malte.Timmermann@sun.com> <
> mailto:Malte.Timmermann@sun.com>
:
>
>
>
> I don't agree on "require user agents to limit this to no more
than 3
> times a second".
>
> I must admit that I don't believe a higher frequency would make any
> sense for anything, but People have different needs, and if someone
for
> what every reason needs a higher frequency, the application should
be
> allowed to support this.
>
>
>
>
> Strongly disagree Malte.
>
> If there is a riks of causing an epeleptic fit, then I'd like
> to see a 'shall' statement in the standard requiring
> nothing more than 3 times per second.
>
> Peoples needs are my concern too.
>
> regards
>
>
>
>
>