Graphics Accessibility API Mappings

W3C Editor's Draft

More details about this document
This version:
https://w3c.github.io/graphics-aam/
Latest published version:
https://www.w3.org/TR/graphics-aam-1.0/
Latest editor's draft:
https://w3c.github.io/graphics-aam/
History:
https://www.w3.org/standards/history/graphics-aam-1.0/
Commit history
Editors:
James Nurthen (Adobe)
Former editors:
(Igalia, S.L.) (until August 2023)
(W3C) (until August 2023)
(IBM Corporation) (until September 2016)
(Knowbility) (until August 2017)
Authors:
(IBM Corporation)
(Knowbility)
(W3C)
Feedback:
GitHub w3c/graphics-aam (pull requests, new issue, open issues)

Abstract

The Graphics Accessibility API Mappings defines how user agents map the WAI-ARIA Graphics Module [GRAPHICS-ARIA-1.0] markup to platform accessibility APIs. It is intended for user agent developers responsible for accessibility in their user agent so that they can support the accessibility of graphics such as that created for [SVG] or [HTML52].

The implementation of this specification in user agents enables authors to produce more accessible graphics by conveying common graphics semantics to assistive technologies. It provides Accessibility API Mapping guidance for the roles defined in the WAI-ARIA Graphics Module [GRAPHICS-ARIA-1.0].

The Graphics Accessibility API Mappings is part of the WAI-ARIA suite described in the WAI-ARIA Overview.

Status of This Document

This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.

This is an Editor's Draft of Graphics Accessibility API Mappings 1.0 by the SVG Accessibility Task Force, a joint task force of the Accessible Rich Internet Applications Working Group and the SVG Working Group. It provides guidance for mapping roles in WAI-ARIA Graphics Module [GRAPHICS-ARIA-1.0] to accessibility APIs, and complements SVG-specific mappings in the SVG Accessibility API Mappings [SVG-AAM-1.0]. It extends Core Accessibility Mappings 1.1 [CORE-AAM-1.1], and is part of a suite of similar technology-specific Accessibility API Mappings specifications.

Feedback on any aspect of the specification is accepted. For this publication, the SVG Accessibility Task Force particularly seeks feedback on the following questions:

To comment, file an issue in the W3C graphics-aam GitHub repository. If this is not feasible, send email to public-aria@w3.org (comment archive). In-progress updates to the document may be viewed in the publicly visible editors' draft.

This document was published by the Accessible Rich Internet Applications Working Group as an Editor's Draft.

Publication as an Editor's Draft does not imply endorsement by W3C and its Members.

This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.

This document was produced by a group operating under the W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.

This document is governed by the 03 November 2023 W3C Process Document.

1. Introduction

This section is non-normative.

The Graphics Accessibility API Mappings specification provides role mappings for the roles in the WAI-ARIA Graphics Module [GRAPHICS-ARIA-1.0].

For web documents and applications, the essential semantic information is encapsulated within the Document Object Model (DOM). Assistive technologies obtain this information from the user agent, which maps elements and attributes to the platform Accessibility API.

The original suite of element semantics defined by WAI-ARIA 1.0 only considered graphics as individual embedded images, with no interactivity or meaningful semantic structure. It was therefore not sufficient for communicating complex graphics, such as labelled diagrams or data charts, or for interactive graphics. The WAI-ARIA Graphics Module defines a core set of three roles that can convey the structure of a graphic. This specification defines how user agents should expose those roles to the accessibility APIs currently in use, so that the semantic information is available to assistive technologies that use those APIs.

For an introduction to WAI-ARIA, see the WAI-ARIA Overview. It is part of a set of resources that define and support the WAI-ARIA specification, including the following documents:

2. Conformance

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

The key words MAY, MUST, MUST NOT, OPTIONAL, RECOMMENDED, REQUIRED, SHALL, SHALL NOT, and SHOULD in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2.1 Conformance

The main content of this specification is normative and defines requirements that impact conformance claims. Introductory material, appendices, sections marked as "non-normative" and their subsections, diagrams, examples, and notes are informative (non-normative). Non-normative material provides advisory information to help interpret the guidelines but does not create requirements that impact a conformance claim.

Normative sections provide requirements that user agents must follow for an implementation to conform to this specification. The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, RECOMMENDED, MAY, and OPTIONAL in this document are to be interpreted as described in Keywords for use in RFCs to indicate requirement levels [RFC2119]. RFC-2119 keywords are formatted in uppercase and contained in an element with class="rfc2119". When the keywords shown above are used, but do not share this format, they do not convey formal information in the RFC 2119 sense, and are merely explanatory, i.e., informative. As much as possible, such usages are avoided in this specification.

Normative sections provide requirements that authors, user agents and assistive technologies MUST follow for an implementation to conform to this specification.

Non-normative (informative) sections provide information useful to understanding the specification. Such sections may contain examples of recommended practice, but it is not required to follow such recommendations in order to conform to this specification.

3. Mapping WAI-ARIA to Accessibility APIs

3.1 General rules for exposing WAI-ARIA semantics

This section MUST conform to General rules for exposing WAI-ARIA semantics in [CORE-AAM-1.1].

4. Conflicts between native markup semantics and WAI-ARIA

User agents MUST conform to Conflicts between native markup semantics and WAI-ARIA in [CORE-AAM-1.1].

5. Exposing attributes that do not directly map to accessibility API properties

User agents MUST conform to Exposing attributes that do not directly map to accessibility API properties in [CORE-AAM-1.1].

6. Role mapping

Platform accessibility APIs traditionally have had a finite set of predefined roles that are expected by assistive technologies on that platform and only one or two roles may be exposed. In contrast, WAI-ARIA allows multiple roles to be specified as an ordered set of space-separated valid role tokens. The additional roles are fallback roles similar to the concept of specifying multiple fonts in case the first choice font type is not supported.

6.1 General Rules

User agents MUST conform to the Role Mapping General Rules accessibility API computational requirements in [CORE-AAM-1.1].

6.2 Role Mapping Table

This section defines how roles in graphics map to platform accessibility APIs based on their native host language semantics and when WAI-ARIA roles are applied. This section refers directly to the Core Accessibility API Mappings specification.

6.2.1 graphics-document

Graphics-ARIA Specification graphics-document
Computed Role graphics-document
MSAA + IAccessible2 Role + Other IAccessible2 Features

ROLE_SYSTEM_DOCUMENT + STATE_SYSTEM_READONLY

IAccessible2: Object attribute xml-roles:graphics-document.

UIA Control Type + Other Features Control Type: 'Document'.
ATK/AT-SPI Role

Expose ROLE_DOCUMENT_FRAME and object attribute xml-roles:graphics-document.

AXAPI AXRole: AXGroup
AXSubrole: AXDocument
AXRoleDescription: 'document'

6.2.2 graphics-object

Graphics-ARIA Specification graphics-object
Computed Role graphics-object
MSAA + IAccessible2 Role + Other IAccessible2 Features ROLE_SYSTEM_GROUPING +

IAccessible2: Object attribute xml-roles:graphics-object.

UIA Control Type + Other Features Control Type: 'Group'.
ATK/AT-SPI Role

Expose ROLE_PANEL and object attribute xml-roles:graphics-object.

AXAPI AXRole: AXGroup
AXSubrole: <nil>
AXRoleDescription: 'group'

6.2.3 graphics-symbol

Graphics-ARIA Specification graphics-symbol
Computed Role graphics-symbol
MSAA + IAccessible2 Role + Other IAccessible2 Features ROLE_SYSTEM_GRAPHIC

IAccessible2: Object attribute xml-roles:graphics-symbol.

UIA Control Type + Other Features Control Type: 'Image'.
ATK/AT-SPI Role

Expose ROLE_IMAGE and object attribute xml-roles:graphics-symbol.

AXAPI AXRole: AXImage
AXSubrole: <nil>
AXRoleDescription: 'image'

A. Change Log

The full commit history to Graphics Accessibility API Mappings 1.0 is available.

A.1 Substantive changes since the First Public Working Draft

B. Acknowledgments

This section is non-normative.

The following people contributed to the development of this document.

B.1 Participants active in the SVG accessibility task force at the time of publication

B.2 Participants active in the ARIA WG at the time of publication

B.3 Enabling funders

This publication has been funded in part with U.S. Federal funds from the Department of Education, National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR), initially under contract number ED-OSE-10-C-0067, then under contract number HHSP23301500054C, and now under HHS75P00120P00168. The content of this publication does not necessarily reflect the views or policies of the U.S. Department of Education, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.

C. References

C.1 Normative references

[CORE-AAM-1.1]
Core Accessibility API Mappings 1.1. Joanmarie Diggs; Joseph Scheuhammer; Richard Schwerdtfeger; Michael Cooper; Andi Snow-Weaver; Aaron Leventhal. W3C. 14 December 2017. W3C Recommendation. URL: https://www.w3.org/TR/core-aam-1.1/
[RFC2119]
Key words for use in RFCs to Indicate Requirement Levels. S. Bradner. IETF. March 1997. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc2119
[RFC8174]
Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words. B. Leiba. IETF. May 2017. Best Current Practice. URL: https://www.rfc-editor.org/rfc/rfc8174

C.2 Informative references

[ACCNAME-AAM-1.1]
Accessible Name and Description Computation 1.1. Joanmarie Diggs; Bryan Garaventa; Michael Cooper. W3C. 18 December 2018. W3C Recommendation. URL: https://www.w3.org/TR/accname-1.1/
[GRAPHICS-ARIA-1.0]
WAI-ARIA Graphics Module. Amelia Bellamy-Royds; Joanmarie Diggs; Michael Cooper. W3C. 2 October 2018. W3C Recommendation. URL: https://www.w3.org/TR/graphics-aria-1.0/
[HTML52]
HTML 5.2. Steve Faulkner; Arron Eicholz; Travis Leithead; Alex Danilo; Sangwhan Moon. W3C. 28 January 2021. W3C Recommendation. URL: https://www.w3.org/TR/html52/
[infra]
Infra Standard. Anne van Kesteren; Domenic Denicola. WHATWG. Living Standard. URL: https://infra.spec.whatwg.org/
[SVG]
Scalable Vector Graphics (SVG) 1.0 Specification. Jon Ferraiolo. W3C. 4 September 2001. W3C Recommendation. URL: https://www.w3.org/TR/SVG/
[SVG-AAM-1.0]
SVG Accessibility API Mappings. Amelia Bellamy-Royds; Ian Pouncey. W3C. 10 May 2018. W3C Working Draft. URL: https://www.w3.org/TR/svg-aam-1.0/
[WAI-ARIA-1.0]
Accessible Rich Internet Applications (WAI-ARIA) 1.0. James Craig; Michael Cooper et al. W3C. 20 March 2014. W3C Recommendation. URL: https://www.w3.org/TR/wai-aria/
[WAI-ARIA-1.1]
Accessible Rich Internet Applications (WAI-ARIA) 1.1. Joanmarie Diggs; Shane McCarron; Michael Cooper; Richard Schwerdtfeger; James Craig. W3C. 14 December 2017. W3C Recommendation. URL: https://www.w3.org/TR/wai-aria-1.1/
[WAI-ARIA-PRACTICES-1.1]
WAI-ARIA Authoring Practices 1.1. Matthew King; JaEun Jemma Ku; James Nurthen; Zoë Bijl; Michael Cooper. W3C. 19 May 2022. W3C Working Group Note. URL: https://www.w3.org/TR/wai-aria-practices-1.1/