1956415 - Disable UIA when JAWS or NVDA are running

Status: RESOLVED FIXED

(Core :: Disability Access APIs, task)

Description

[James Teh [:Jamie]]

I had hoped JAWS would just ignore Gecko's native UIA implementation. However, if Gecko native UIA is enabled, JAWS is all kinds of broken. We'll need to disable native UIA if JAWS is detected.

Comment 1

[James Teh [:Jamie]]

Attachment: Bug 1956415 part 1: Add Compatibility::IsUiaEnabled.

Initially, this just checks the accessibility.uia.enable pref.
Other checks will be added in subsequent patches.
All callers which previously checked the pref directly now call this function.

Comment 2

[James Teh [:Jamie]]

Attachment: Bug 1956415 part 2: Disable native UIA when JAWS, other Vispero products or NVDA are detected.

JAWS and NVDA will continue to use IA2 in Firefox.
However, enabling native UIA in Gecko causes them both to try to use UIA, which causes breakage.
The same is presumably true for other Vispero products, as they use components shared with JAWS.
Future versions of these products will handle this correctly themselves.
Until then, disable UIA when these products are detected.

As part of this, the UIA pref has been changed from a bool to a uint32_t.
This will cause existing configurations of this pref to be reset to the default, but this is okay because this pref has never been documented, exposed in the UI or intended for public usage.
This allows for three values: 0 to never enable, 1 to always enable and 2 to enable unless incompatible clients are detected.
This makes it possible for developers to test those clients with Gecko's UIA implementation when necessary.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/75e9b40ec5d9
part 1: Add Compatibility::IsUiaEnabled. r=morgan
https://hg.mozilla.org/integration/autoland/rev/d36718978096
part 2: Disable native UIA when JAWS, other Vispero products or NVDA are detected. r=morgan

Comment 4

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/75e9b40ec5d9
https://hg.mozilla.org/mozilla-central/rev/d36718978096