Problem Summary

Plugins cannot currently provide accessible information about their contents on non-Windows platforms. This is Mozilla bug 78414.

Glossary

Accessibility - the degree to which a product is accessible by as many people as possible.
Assistive Technology (AT) - a piece of software or hardware that connects to the system's accessibility services to provide assistance to the user. This assistance can come in the form of a head tracking system for a user unable to use a mouse, a screen reader for a person with vision impairments, etc.
Microsoft Active Accessibility (MSAA) - the standard accessibility API for Windows 95 through Windows XP. Accessible objects in MSAA inherit from the IAccessible interface.
Accessibility Toolkit (ATK) - the standard accessibility API on Linux.

Related Approaches

On Windows, plugins can provide their own accessibility support by responding to the WM_GETOBJECT WinEvent and returning an instance of IAccessible. Firefox (and other browsers) will call this WinEvent on the plugin object and if an IAccessible is returned, register the accessible into the accessibility hierarchy.

API Requirements

Plugins should be able to easily provide an accessible implementation (in the native accessibility toolkit) to the Browser
The Browser should inject the plugin's accessible into its accessible hierarchy
The lifetime of the plugin's accessible should be the same as the lifetime of the plugin.

Current Proposal

Specification

NPAPI Native Accessibility Support

Last modified: June 26, 2009
Author: Brad Taylor, Novell, Inc.
Contributors:

NPAPI:NativeAccessibility

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