Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 0c6fba63ba28ce7dcb2cc90e9afe32acbb488043
https://github.com/WebKit/WebKit/commit/0c6fba63ba28ce7dcb2cc90e9afe32acbb488043
Author: Andres Gonzalez <[email protected]>
Date: 2026-07-28 (Tue, 28 Jul 2026)
Changed paths:
A
LayoutTests/accessibility/mac/text-stitching-selection-notification-element-expected.txt
A
LayoutTests/accessibility/mac/text-stitching-selection-notification-element.html
M Source/WebCore/accessibility/AXCoreObject.cpp
M Source/WebCore/accessibility/AXCoreObject.h
M Source/WebCore/accessibility/mac/AXObjectCacheMac.mm
M Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm
Log Message:
-----------
AX: SelectedTextChanged should report the stitch representative, not a
stitched-away text member
https://bugs.webkit.org/show_bug.cgi?id=320427
<rdar://problem/183385743>
Reviewed by Tyler Wilcock.
Accessibility text stitching combines a paragraph's inline text runs into a
single
representative AXStaticText and removes the individual (stitched-away) runs
from their
parent's exposed children (see childrenAfterStitching in AXCoreObject.cpp).
Because those
members are no longer present in their parent's children, any AT-facing API
that hands a
single object back to the client must resolve a stitched-away member to its
representative;
otherwise it exposes an element that cannot be found in the tree it is
supposedly part of.
309924@main added that resolution for the NSAccessibilityUIElementForTextMarker
path
(handleUIElementForTextMarkerAttribute), but the SelectedTextChanged
notification posted by
postTextSelectionChangePlatformNotification still targeted the stitched-away
member. That
notification is the one an assistive client such as VoiceOver uses to follow
the caret while
the user reads a read-only web document line by line with the arrow keys (for
example, an
HTML mail message body). When the caret lands inside a stitched-away run, the
client is handed
the member object that stitching removed from its parent's children. On the next
layout-changed notification VoiceOver re-validates that its focused element is
still among its
parent's children, does not find it, concludes the focused element has been
removed, and
re-homes focus to the web area, re-announcing the entire message from the
beginning. The
AXUIElementForTextMarker fix did not cover this case because the element the
client caches for
the caret comes from the selection-change notification, not from resolving a
text marker.
This patch factors the "resolve a stitched-away object to its representative"
step into a
single shared helper, AXCoreObject::stitchRepresentativeOrSelf(), and routes
both AT-facing
single-object paths through it:
1. handleUIElementForTextMarkerAttribute now calls the helper, replacing
the inline
resolution added in 309924@main.
2. postTextSelectionChangePlatformNotification calls the helper before
building and posting
the notification, so the change element
(NSAccessibilityTextChangeElement) and the
object the notification is posted on are the exposed representative.
The helper resolves the representative tree-agnostically via
AXTextMarker { treeID(), representativeID, 0 }.object(), and returns the object
itself when it
is not stitched away, so it is a no-op for non-stitched content and behaves
correctly on both
the main-thread and the isolated tree. Stitching's presentation is unchanged:
the individual
members are still removed from their parent's children, and only the single
object handed to
the assistive client for the caret's position is corrected to the
representative that is
actually present in the tree. The selected-text-marker range carried in the
notification is
still computed from the live selection, so the reported caret range is
unaffected.
The new test moves the caret into a stitched-away run of a read-only paragraph
using the
accessibility selection API and verifies that the SelectedTextChanged change
element is the
representative, whose value spans the whole run, rather than the individual
member.
Test: accessibility/mac/text-stitching-selection-notification-element.html
*
LayoutTests/accessibility/mac/text-stitching-selection-notification-element-expected.txt:
Added.
*
LayoutTests/accessibility/mac/text-stitching-selection-notification-element.html:
Added.
* Source/WebCore/accessibility/AXCoreObject.cpp:
(WebCore::AXCoreObject::stitchRepresentativeOrSelf):
* Source/WebCore/accessibility/AXCoreObject.h:
* Source/WebCore/accessibility/mac/AXObjectCacheMac.mm:
(WebCore::AXObjectCache::postTextSelectionChangePlatformNotification):
* Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperMac.mm:
(handleUIElementForTextMarkerAttribute):
Canonical link: https://commits.webkit.org/318112@main
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