My point is that we don't currently have a way of handling this decently
with IA2 and that we need new API calls. Saying "just faf around with
accNavigate and try all sorts of different stuff until you find what you
want" isn't good enough IMO, not least because it's horribly
unperformant cross-proc. If we're going to have gaps at the start/in the
middle of rows, we need some sort of table navigation function that can
handle different types of navigation. Currently, there is no such function.
Jamie
On 6/01/2016 11:00 AM, Richard Schwerdtfeger wrote:
Jamie,
I have to agree with Dominic that you have a lot of different what ifs
for determining where to go when a cell is empty. I think you need to
be able to pass a parameter that asks the browser to go where you want
based on a set of criteria.
For example, So, what if several rows are skipped? When does the
situation become problematic?
What condition do you want to be met?
e.g. a parameter that tells us what to do if an empty cell is encountered:
GOTO_FIRST_NONEMPTY_ADJACENT_CELL
What I am getting at is what is the algorithm you want the user agent
to follow when an empty cell is encountered. Does it Vary based on a
parameter. Do you want hidden cells to be ignored?
Rich
Rich Schwerdtfeger
Inactive hide details for James Teh ---01/05/2016 04:50:38 PM---On
5/01/2016 7:53 AM, Richard Schwerdtfeger wrote: >James Teh
---01/05/2016 04:50:38 PM---On 5/01/2016 7:53 AM, Richard
Schwerdtfeger wrote: >
From: James Teh <[email protected]>
To: Richard Schwerdtfeger/Austin/IBM@IBMUS, Dominic Mazzoni
<[email protected]>
Cc: IAccessible2 mailing list
<[email protected]>,
[email protected]
Date: 01/05/2016 04:50 PM
Subject: Re: [Accessibility-ia2] aria-colcount and aria-rowcount
mapping, again
------------------------------------------------------------------------
On 5/01/2016 7:53 AM, Richard Schwerdtfeger wrote:
Although it is possible to have 2 cells I don't think this even
close to the norm.
Two cells was just an extreme example to demonstrate the issue. The
point is that gaps at the start or middle of a row are problematic.
Why would we we not just have the screen reader ask to go to a row
and column number?
Because if there is a gap, incrementing row or column by one isn't
sufficient. It could be 1, 2 or an arbitrary number.
It is not difficult to ask the user agent to navigate to compute
the effective cell to the right and ask for the user agent to
navigate there.
It's probably always true that navigating to the adjacent cell in the
next column is as simple as accNavigate with NAVDIR_NEXT. However,
navigating to the adjacent cell in the next row is not so simple. What
if several rows are skipped?
We can add a parameter that states to navigate to the first
non-empty cell to the ... or whatever algorithm we choose.
Add a parameter to what? I think this would require a new function,
which is what I was suggesting.
Dominic wrote:
Jamie, as an alternative, couldn't the screen reader try
navigating to the next / previous cell using the row, column
index, but if that fails, fall back on DOM navigation?
For example, given a current cell (x, y), if the user wants to go
right - to the next cell in the same row, try (x + 1, y) but if
that's empty, use the accessibility tree to navigate to the next
sibling.
I suppose we could do that, but it's pretty inelegant. Oh look, we
have a table interface... but uh, sometimes it's not very useful, so
you might need to use tree navigation. It's not so bad for columns i
guess, but see below for rows.
Similarly, given (x, y) if the user wants to go down - to the same
column in the next row, try (x, y + 1), but if that's empty, use
the accessibility tree to navigate to the next row,
Navigating to the next row has two problems:
1. It's not a simple navigation, since there might be
thead/tbody/rowgroup elements to think about. Sure, it's just a
depth-first traversal, but now we're starting to get fairly
complicated for what should be a simple operation.
2. What if the next row doesn't include that column, but there is a
row 3 rows beyond that that does? Surely we should move to the row
with the matching column. That's not possible with your algorithm.
then try column x in that row, and if that fails, navigate to the
first cell in that row.
We never want to fall back to the first column like that. If a user
moves down a row, they expect to move down a row, not down and across
(excepting column spans).
Jamie
--
James Teh
Executive Director, NV Access Limited
Ph +61 7 3149 3306
_www.nvaccess.org_ <http://www.nvaccess.org/>
Facebook: _http://www.facebook.com/NVAccess_
Twitter: @NVAccess
SIP: [email protected]_ <mailto:[email protected]>
--
James Teh
Executive Director, NV Access Limited
Ph +61 7 3149 3306
www.nvaccess.org
Facebook: http://www.facebook.com/NVAccess
Twitter: @NVAccess
SIP: [email protected]
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