OLYM-9024: [macOS] Give the accessibility text field its semantics label and value - #8

Verdict: approved

The fix is right for OLYM-9024. On macOS every Flutter text field reaches VoiceOver as one hidden FlutterTextField. The change gives it the semantics label as its name, and the node's value while it is not being edited. Nothing must change before the merge. Three suggestions below; none blocks.

How I read it

• The PR is one commit on top of OlymEDRSupport (1 ahead, 0 behind), so it merges cleanly. I read the diff and the files around it from GitHub at 98516cf.
• What I checked:
  1. The new test can fail. On the base, accessibilityLabel is nil and accessibilityValue is the cell's empty string, so both checks fail there.
  2. Every door. Every macOS text-field node becomes a FlutterTextField (FlutterPlatformNodeDelegateMac::Init and NodeDataChanged, on IsTextField()). The bridge puts the label in kName and the value in kValue (accessibility_bridge.cc lines 534-542). So this one class covers every text field. iOS, Windows and Linux use other code and are not touched.
  3. The platform. macOS, where the bug was seen. The PR says it was tried with real VoiceOver on sysmac1.
  4. Privacy. A password field's semantics value is already bullets (editable.dart lines 1347-1349). So reporting the node's value before editing leaks nothing.
  5. Docs. UPSTREAM-CANDIDATES.md has entry 12. Olym's own docs mention only OLYM-9141's parent problem, which this does not change.
  • No new warnings, dead code, logging, workarounds or dependencies.

Findings

1. Suggestion: a stale editing field still reads another field's text

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterTextInputSemanticsObject.mm:121

• What. accessibilityValue uses the editor's string whenever _plugin.client == self. The client changes only at the next startEditing, so it can be stale. The fixed build's own dump (OLYM-9024-fixed-ax-tree.txt on the ticket) shows it: after typing "Opera House" in Title, Description also has value="Opera House", although it is empty on screen.
• Why it matters. VoiceOver would read "Description, Opera House" for an empty Description box. This is not new (Description read the same before this PR), and the PR says so. But it is now the one case where the value is wrong, and OLYM-9141's description does not cover it.
• What to do. Use the editor's string only while this field is the client and Flutter's input focus is on its node (the tree's focus_id, which the bridge sets from isFocused, accessibility_bridge.cc lines 574-582). Otherwise report the node's value. Note that GetDelegate()->GetFocus() is the last node VoiceOver focused, not the input focus, so it would miss the mouse-click case. If you leave it for later, add this case to OLYM-9141 so it is not lost.

2. Suggestion: the test covers only the "not being edited" path

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterTextInputSemanticsObjectTest.mm:95-101

• What. Nothing checks that the live editor string wins while the field is the client, or that an empty label falls back to nil.
• Also. Because role is now kTextField, delegate.Init already builds its own FlutterTextPlatformNode, and the test then makes a second one. Checking delegate.GetNativeViewAccessible() instead would test the object the bridge really hands to VoiceOver.
• What to do. Add a client case (make the field the plugin's client, give it a different string with updateString:withSelection:, expect that string) and an empty-label case. Upstream reviewers will likely ask for both when entry 12 is filed.

3. Suggestion: date the upstream check in entry 12

UPSTREAM-CANDIDATES.md:206

• What. The file's header says the entries were "Checked against flutter/flutter master on 2026-10-13". Entry 12 was checked later.
• What to do. Put the date you checked upstream master on its Upstream: line, so no one reads it as part of the October check.