2070914 - The split view splitter reports no ARIA position until one has been measured

Status: RESOLVED FIXED

(Toolkit :: UI Widgets, task, P3)

Description

[Florian Quèze [:florian]]

split-view-splitter in toolkit/content/widgets/tabbox.js sets aria-valuenow only asynchronously. Until the first measurement arrives it is a role="separator" with no position for a screen reader to report.

browser_tab_splitview_resize.js and browser_tab_splitview_telemetry.js fail the mochitest accessibility checks for this once the checks require a position, because the check runs at click time before the attribute exists. Setting a position when the splitter is created fixes both.

Comment 1

[Florian Quèze [:florian]]

Attachment: Bug 2070914 - Give the split view splitter an ARIA position before one has been measured, r=#tabbrowser-reviewers,Jamie.

The splitter is a separator with tabindex="0", so ARIA requires it to report a
position, but it has none until a layout flush, and the values are removed
again when a split view is torn down. Between creation and that first flush,
and from a teardown until the next one, a screen reader finds a window splitter
that reports no position at all.

Comment 2

[Florian Quèze [:florian]]

Attachment: Bug 2070914 - Let a focusable ARIA separator satisfy the mochitest accessibility checks, r=Jamie.

assertCanBeClicked can never accept a window splitter: findInteractiveAccessible
and assertInteractive take only INTERACTIVE_ROLES, and the action count rule
demands an accessible action that ARIAMap.cpp gives ARIA separator and scrollbar
never. Making all of INTERACTIVE_IF_FOCUSABLE_ROLES reachable would also make
focusable gridcells findable and bypass isAccessibleGridcell, so this covers
those two roles only, and requires aria-valuenow in the action count's place.
The only node it newly judges tree-wide is the split view splitter in
tabbox.js.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/9fbac5a6e20e
https://hg.mozilla.org/integration/autoland/rev/d7bc071addea
Let a focusable ARIA separator satisfy the mochitest accessibility checks, r=Jamie,devtools-reviewers,nchevobbe.

Comment 4

[Serban Stanca [:SerbanS]]

Reverted this because it was causing Linux mochitests failures.

• Revert link
• Push with failures
• Failure Log 1
• Failure Log 2
• Failure Log 3

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d2fc2f22fe59
https://hg.mozilla.org/integration/autoland/rev/40590e94cecd
Let a focusable ARIA separator satisfy the mochitest accessibility checks, r=Jamie,devtools-reviewers,nchevobbe.

Comment 6

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/40590e94cecd