RE: Allowed values of aria-autocomplete for the combobox role

> Cynthia's point is that a <select> without @multiple renders as a combobox. (The @size also has to be absent or not greater than "1"). 
If the @multiple is present, then <select> renders as a listbox, but if it's absent it renders as a combobox.

Thanks, that makes sense for native HTML select elements, the mixed termonology is what was throwing me, since this automatic conversion doesn't actually take place with the ARIA roles.

E.G role=listbox maps to 'list' no matter which supporting attributes are set, and role=combobox maps to 'combobox no matter which supporting attributes are set. Just confirmed in FF on Win7.

The implication regarding select seemed to be that if role=combobox didn't have aria-autocomplete set, that it would somehow automatically map to 'list' as a Listbox, which it doesn't.

-----Original Message-----
From: Joseph Scheuhammer [mailto:clown@alum.mit.edu] 
Sent: Thursday, December 03, 2015 7:17 AM
To: Matt King <a11ythinker@gmail.com>; 'Cynthia Shelly' <cyns@microsoft.com>; 'PF' <public-pfwg@w3.org>
Subject: Re: Allowed values of aria-autocomplete for the combobox role

Matt, Bryan,

On 2015-12-02 8:13 PM, Matt King wrote:
>
> I think a widget that has a textbox, a list, and acts like a select 
> would be a combobox with autocomplete set to list.
>
> Can you describe a widget that acts like a select, has a textbox, and 
> does not have autocomplete? A select has a list and allows only 
> selection of a value from that list.
>

Cynthia's point is that a <select> without @multiple renders as a combobox.  (The @size also has to be absent or not greater than "1").  
If the @multiple is present, then <select> renders as a listbox, but if it's absent it renders as a combobox.

In terms of the a11y tree, <select> with no @multiple and no @size has an AAPI role of combobox [1].  Furthermore, the combobox accessible does
*not* have an autocompletion state.  It's as if aria-autocomplete="none".

> If typing in the textbox of such a widget doesn't either complete 
> inline based on values in the list or narrow the list and allow 
> selection from the list, then what is the purpose of the textbox?

Suppose a developer implements a "find" function for a text editor using a combobox UI.  The first time it is used, there are no items in its list.  The user types some string in the textfield and hits enter.  
Aside from searching the text, the combobox also stores that string as the first entry in its associated list.  Over time, the combobox will collect all of the user's search strings.  At any given time, the user can either (1) type a string in the textbox and use that to search, or
(2) pop open the associated listbox and choose one its options as the search string.

Suppose further that the developer does not implement any kind of autocompletion.  Users can only ever either type a string in the textbox for the search, or they can pop open the list and choose a previous string to search for again.  In that case, aria-autocomplete="none".


[1] http://www.w3.org/TR/html-aam-1.0/#el-select-combobox

--
;;;;joseph.

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Received on Thursday, 3 December 2015 16:39:05 UTC