Re: alertdialog versus dialog questions, also modal versus non-modal

Looks like my last response didn't make it through, so I'll try again.

It's a useful for a screen reader to know if the current container is an 
alertdialog vs. a dialog.
Typically a dialog is not read from start to end. The title, current 
focus, and probably any groupbox or pane title would be read. Otherwise 
you'd get quite verbose preferences dialogs. It wouldn't be useful to read 
the whole thing from start to end.

However, in many cases you don't want the user to miss the main message of 
a dialog. An alertdialog is just a simple message like "Your mailbox is 
full, please clean unwanted mails, Ok, button". Because the screen reader 
knows it's an alertdialog is knows to read the whole thing as soon as 
anything in the dialog gets focused.

There is no way currently to indicate that a dialog is modal or modeless. 
I'm not sure how a sighted person figures this out, other than knowing 
from context or trying to focus outside of the dialog. If someone can 
state an important reason to expose that then it should be considered 
after ARIA 1.0. IIRC the group has decided not to take on new properties 
since we're trying to get the spec ready for last call.

- Aaron



From:
James Craig <jcraig@apple.com>
To:
W3C WAI-XTECH <wai-xtech@w3.org>
Date:
05/28/2008 01:37 AM
Subject:
alertdialog versus dialog questions, also modal versus non-modal




Apologies if this question has already been discussed, but I fail to 
see a meaningful difference in the ARIA roles for alertdialog and 
dialog. AFAIK, the only discussion of this on the xTech list is the 
following, where Al points out an implementation problem with 
@role="alert dialog"

http://lists.w3.org/Archives/Public/wai-xtech/2008Apr/0028.html

Implementation issues aside, it seems to me that there is no 
meaningful difference between an alert dialog and a standard dialog. 
Both roles use an application window that receives focus and requires 
some form of user input or acknowledgment. If this is true, they 
should both be standard dialogs, because @role="dialog" appears to be 
just a child role of @role="alert" that also receives focus. Please 
correct me if I'm missing something in the reading or implementation.

For reference:

alertdialog <http://www.w3.org/TR/wai-aria/#alertdialog>
                 A separate window (may be simulated) with an alert, where 
initial
                 focus goes to the window or a control within it.

dialog <http://www.w3.org/TR/wai-aria/#dialog>
                 A dialog is a small application window that sits above 
the application
                 and is designed to interrupt the current processing of an 
application
                 in order to prompt the user to enter information or 
require a response.

The other bit that's not clear from this wording is how to achieve a 
modal versus non-modal dialog. Since dialog is "designed to interrupt 
the current processing of an application," I assume that means it 
maintains a "modal" state and intercepts all input until it is 
dismissed. Have I missed some other allowance for non-modal dialogs?

Thanks,
James Craig