Proposed changes to combobox in ARIA 1.2

There are a wide variety of issues related to combobox that are open in
ARIA, Authoring Practices, and HTML-AAM.  We will be discussing them at
TPAC.

 

I have drafted ARIA pull request 1051 with the aim of making it possible to
readily resolve all the issues by addressing a couple of common causes
rooted in the definition and structure of combobox specified by ARIA 1.1. I
have copied the description of the pull request below. The description
includes a link to the presentation I am developing for running the
discussion at TPAC. There is a lot to digest. I hope people will be able to
pre-read and comment in the PR or on the specific issue to which your
comment is relevant.

 

Thanks!

Matt

 

Pull request 1051: https://github.com/w3c/aria/pull/1051

 

The purpose of this pull request is to revise combobox issues by better
aligning the specification with what has been long supported by both
browsers and assistive technologies. I am developing an explanitory
presentation to be discussed at TPAC 2019, which is available at
http://a11y.pro/combobox-TPAC2019/

 

### Summary of changes in this pull request

 

1. Revise definition of combobox to encompass implementations that do not
support text editing, such as some implementations of the HTML select
element by browsers.

2. Revise description of the structure of combobox so the element with the
combobox role is the focused element instead of a wrapper that is not
focusable and the relationship with the popup is defined by aria-controls.

3. Change the super class to input from select so it describes the actual
structure; select is a composite and the revised combobox structure does not
include any focusable descendants. This also has the beneficial side effect
of removing aria-orientation, which is not applicable.

4. Add aria-activedescendant as a supported property because it is no longer
inherrited from its super class.

5. Remove all required owned elements. A combobox no longer has any
descendants.

6. Change section 2.3 (id="managingfocus") to remove combobox from the list
of composite widgets and for clarity and compatibility with revised combobox
structure.

7. Editorial revisions to the definition and description of the
aria-activedescendant property to reflect the changes to the combobox
structure.

 

### Issues resolved by this pull request

 

* #998: The Combobox 1.0 design pattern references incorrectly include
aria-owns instead of aria-controls.

* #776: aria-controls a required property for Combobox? 

* #716: Combobox: aria-controls or owns should be on input, not on combobox
element, and only when combobox is expanded

* #909: Clarify combobox label placement

* #1046: Does combobox require an accessible name? 

* #893: The ARIA 1.1 Combobox design pattern endorses unlabelled form fields
as normative spec.

* #742: role combobox either misses text or is incorrect regarding role
searchbox

* #817: Update combobox spec as per html spec/html-aam mapping for
`<select>`* [HTML-AAM: select element should map to listbox role regardless
of presentation 

 

### Example Implementation

 

View an test an example implementation of the new pattern in the Authoring
Practices Guide:

https://raw.githack.com/w3c/aria-practices/aria1.2-combobox-proposal/example
s/combobox/combobox-autocomplete-list.html

 

### Preview Changes

 

View the rendered changes in the compare branch for this pull request:

https://raw.githack.com/w3c/aria/fix-combobox/index.html#combobox