overflowing content handling - was (Re: Positioned Layout proposal)

Shelby Moore wrote:
>>> Perhaps I can allocate more time thinking about this at some point,
>>> because CSS as it is now really frustrates me. The tsuris seems mostly
>>> to
>>> revolve around the fact that CSS is not designed to support the new Web
>>> applications which want to keep all their content inside the viewport
>>> and
>>> create overflowed scrolled sub-areas instead of overflowing the
>>> viewport.
>>
>> Perhaps this is due to the fact that someone using a keyboard can not
>> easy scroll the page and the overflowed scrolled sub-areas (which are
>> really boxes with overflow:auto) and switch between them. The focus
>> either has to be on the viewport or the overflowed scrolled sub-areas
>> and this focus has to be changed to scroll either one.
>>
>> This is an accessibility issue.
> 
> Afaics, that is an orthogonal concern, which can be handled by the UA.


Firstly can you clarify orthogonal?

   Wikipedia - In mathematics, two vectors are orthogonal if they
   are perpendicular, i.e., they form a right angle.


> For example, the UA may provide Page Up and Page Down keys, and may use
> the the Tab key and/or shortcut keys to move the focus around.  Also the
> UA should give some indication of focus-- afaik they do not now.


This is not just what is handled by the UA. This also includes OS, PC 
and user devices like a mouse or keyboard.


> It is really a failed assumption that all web apps need to scroll
> contiguously in the viewport. Imo, that was a design error.


I would rather suggest that it is a failed assumption by a CSS author 
that overflowing content doesn't have to be scrolled to occasionally, 
especially considering the range we have in display devices.

On the CSS discuss list, I have often seen pages like this.


<!DOCTYPE html>
<html>
<body style="margin:0;">
<div style="overflow: scroll; height: 1000px;">
<div style="height: 1200px; background: white;">content</div>
</div>
</body>
</html>


Even I get lost in there.



> If you are
> really concerned about accessibility and usability, then just ponder the
> how unusable an application is if you are only looking at one tile of it
> and have to scroll the whole app around.


I have a desktop with a mouse and keyboard. Can I ask you what types 
of display devices you using a referring too?

I myself while surfing have been using the scrolling mechanism on the 
mouse and realized that I have to move the mouse outside some 
particular element of the page with overflow with values of auto or 
scroll (example, YouTube). I only know this since I am a CSS author 
that has experimented with overflow. I can imagine some other web user 
with the use of both a mouse and a keyboard not knowing what to do.



-- 
Alan http://css-class.com/

Armies Cannot Stop An Idea Whose Time Has Come. - Victor Hugo

Received on Saturday, 23 October 2010 05:16:17 UTC