[web] Fix MenuAnchor dismiss when semantics enabled by flutter-zl · Pull Request #183093 · flutter/flutter

flutter-zl · 2026-03-01T19:55:05Z

Problem
When semantics are enabled, MenuAnchor does not close when clicking outside it. ClickDebouncer was converting all debounced clicks to SemanticsAction.tap, which bypasses the pointer event pipeline. TapRegionSurface never saw a PointerDownEvent, so onTapOutside was never called and the menu stayed open.

Fix
TapRegionSurface now registers a listener with SemanticsBinding.addSemanticsActionListener to intercept SemanticsAction.tap and SemanticsAction.longPress events. On each action, it hit-tests the render tree at the tapped node's center and calls onTapOutside/onTapInside directly. The inside/outside classification is extracted into a shared _classifyRegions method used by both the pointer and semantics paths.

ClickDebouncer.onClick also calls stopPropagation() before flushing pointer events for the isListening: false case, preventing a duplicate browser click.

Note: consumeOutsideTaps cannot suppress semantics action propagation today. A follow-up API change similar to WidgetsBindingObserver.handleStartBackGesture would be needed. See the TODO in _handleSemanticsAction.

Demo

Before change
https://flutter-demo-14-before.web.app

After change
https://flutter-demo-14-after.web.app

Steps: click Open Menu → click Button A outside the menu.
Before: button fires but menu stays open.
After: button fires and menu closes.

…er events for non-merged nodes.

…scendants parameter.

gemini-code-assist

Code Review

This pull request addresses an issue where MenuAnchor does not dismiss on an outside click when semantics are enabled. A new mergesDescendants flag is introduced and propagated through the semantics system. This flag is used in ClickDebouncer to conditionally flush pointer events for non-merged nodes, which allows TapRegionSurface to detect outside taps. For merged nodes, SemanticsAction.tap is still used to preserve existing behavior. The changes also include updates to tests to cover the new logic. My feedback is focused on improving documentation for the newly introduced parameters.

chunhtai

Can you explain a bit more about the exact repro setup?

is it because the there is an area that it should hit inside a big semantics node, but instead swallowed by the semantics tap? how does the rect looks like in this cases?

chunhtai · 2026-03-12T18:43:14Z

-      // There's a pending queue of pointer events. Prefer sending the tap action
-      // instead of pointer events, because the pointer events may not land on the
-      // combined semantic node and miss the click/tap.
+    if (isMergedNode && isListening) {


merge node may not be the only cases this can be true,

you can have a gesture detector under a Semantics(container: true) which has smaller rect but merge up to the bigger container

Good catch. I broadened the flag from mergesDescendants to absorbedChildSemantics. Instead of only checking _mergeAllDescendantsIntoThisNode, the framework now sets absorbedChildSemantics = true whenever absorbAll encounters a child SemanticsConfiguration that hasBeenAnnotated and has an onTap handler. This covers both MergeSemantics and Semantics(container: true) cases where a smaller tappable child's tap action gets absorbed into a larger container node, causing a rect mismatch.

In the engine, ClickDebouncer.onClick now checks absorbedChildSemantics instead of isMergedNode. When true, it sends SemanticsAction.tap to avoid coordinate miss-hits. When false, it flushes pointer events so TapRegionSurface can detect outside taps and close MenuAnchor.

… containers

flutter-zl · 2026-03-14T01:01:51Z

Can you explain a bit more about the exact repro setup?

is it because the there is an area that it should hit inside a big semantics node, but instead swallowed by the semantics tap? how does the rect looks like in this cases?

The repro setup is the demo app linked in the PR description. A MenuAnchor opens a dropdown menu, and below it are standalone ElevatedButtons. With semantics enabled, each button gets a semantics DOM element overlaid on top of the canvas. When the user clicks a button while the menu is open, the browser fires a click event on the semantics element. ClickDebouncer intercepts it. Previously, it always converted this into SemanticsAction.tap, which goes directly to the button's tap handler, bypassing the pointer event pipeline entirely. Since TapRegionSurface never sees a PointerDownEvent, onTapOutside is never called, and the menu stays open.

mdebbar · 2026-03-16T14:31:48Z

@chunhtai should this be considered a bug in TapRegionSurface if it's not detecting semantics taps outside a region? I think it should detect normal taps and semantics taps.

chunhtai · 2026-03-16T22:13:09Z

Thanks for the info, yeah I agree this is something that probably should be fixed in TapRegionSurface. This will be tricky to implement though since semantics action and gesture rect are two separate channel. there isn't a good way to hook TapRegionSurface to the semantics action without actually participate in the semantics tree.

flutter-zl · 2026-03-24T20:14:35Z

Thanks for the info, yeah I agree this is something that probably should be fixed in TapRegionSurface. This will be tricky to implement though since semantics action and gesture rect are two separate channel. there isn't a good way to hook TapRegionSurface to the semantics action without actually participate in the semantics tree.

TapRegionSurface only knows about PointerDownEvent and PointerUpEvent. It does not know about SemanticsAction, SemanticsActionEvent, or anything from the semantics system. There is no import, no callback, no listener for semantics actions anywhere in this file. @mdebbar what do you think?

mdebbar · 2026-04-02T15:51:10Z

TapRegionSurface only knows about PointerDownEvent and PointerUpEvent. It does not know about SemanticsAction, SemanticsActionEvent, or anything from the semantics system. There is no import, no callback, no listener for semantics actions anywhere in this file.

Yeah, that's the bug 🙂 TapRegion should know about semantics and should take SemanticsAction.tap into account.

As a first step, TapRegion can listen to all semantics actions using:

SemanticsBinding.instance.addSemanticsActionListener(...);

Then, it needs to decide if the received tap was inside or outside. This is the part I'm not sure how to implement. Any ideas @chunhtai ?

I'm assuming we can't use Semantics(onTap: ...) since that would absorb the tap; and TapRegion is designed to passively listen to taps without affecting the rest of the system.

chunhtai · 2026-04-02T16:21:19Z

The only way i can think of is to use SemanticsBinding.instance.addSemanticsActionListener(...) and then see if the semanticnode id is a node under the tapRegion's semantics subtree. We will need to do this in RenderTapRegionSurface

…anticsAction.tap

chunhtai

LGTM

chunhtai · 2026-05-11T21:27:40Z

+  /// the view has no semantics owner, or the node cannot be found. Callers
+  /// should only invoke this in response to a semantics action, in which case
+  /// all three lookups are expected to succeed.
+  ui.Rect? semanticsNodeGlobalRect(int viewId, int nodeId) => null;


nit: rename this getRectOfSemanticsNodeInViewCoordinates.

auto-submit · 2026-05-11T22:07:19Z

autosubmit label was removed for flutter/flutter/183093, because This PR has not met approval requirements for merging. Changes were requested by {mdebbar}, please make the needed changes and resubmit this PR.
The PR author is a member of flutter-hackers and needs 1 more review(s) in order to merge this PR.

Merge guidelines: A PR needs at least one approved review if the author is already part of flutter-hackers or two member reviews if the author is not a member of flutter-hackers before re-applying the autosubmit label. Reviewers: If you left a comment approving, please use the "approve" review action instead.

Previous code change is outdated.

chunhtai

LGTM

…11713) Manual roll requested by bmparr@google.com flutter/flutter@23f6f58...0541913 2026-05-14 98614782+auto-submit[bot]@users.noreply.github.com Reverts "[Windows] Propagate the enabled accessibility state (#184501)" (flutter/flutter#186492) 2026-05-13 srawlins@google.com [dev] Use super parameters in missed spots (flutter/flutter#186193) 2026-05-13 loic.peron@inetum.com [Windows] Propagate the enabled accessibility state (flutter/flutter#184501) 2026-05-13 matt.boetger@gmail.com [flutter_tool] filter out MotionEvent-JNI warning spam from logcat (#174783) (flutter/flutter#186079) 2026-05-13 engine-flutter-autoroll@skia.org Roll Packages from 93cbed6 to 2ec2236 (1 revision) (flutter/flutter#186464) 2026-05-13 mdebbar@google.com [web] Fix untriaged issues link label (flutter/flutter#186465) 2026-05-13 bdero@google.com [Impeller] Namespace user-supplied shaders to prevent entrypoint collisions (flutter/flutter#186332) 2026-05-13 1063596+reidbaker@users.noreply.github.com [flutter_tools] Migrate detectLowCompileSdkVersionOrNdkVersion to AGP task (flutter/flutter#184731) 2026-05-13 jason-simmons@users.noreply.github.com Update the Flutter Gallery web app template files to support running with Wasm (flutter/flutter#186268) 2026-05-13 jason-simmons@users.noreply.github.com [web] Use heap allocation for buffers that would consume too much space on the Wasm stack (flutter/flutter#186228) 2026-05-13 engine-flutter-autoroll@skia.org Roll Skia from 56ca5896c0d9 to 27f7bba22600 (3 revisions) (flutter/flutter#186444) 2026-05-13 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from z7ICmPtn4hspu02zk... to y6uQHA5xUN83IF395... (flutter/flutter#186442) 2026-05-13 engine-flutter-autoroll@skia.org Roll Skia from 6385958d2feb to 56ca5896c0d9 (1 revision) (flutter/flutter#186441) 2026-05-13 engine-flutter-autoroll@skia.org Roll Dart SDK from 9576691c37d8 to 8e30b88e4d5a (1 revision) (flutter/flutter#186429) 2026-05-13 engine-flutter-autoroll@skia.org Roll Skia from 77a21bc723dc to 6385958d2feb (9 revisions) (flutter/flutter#186428) 2026-05-13 164032450+AlexEduV@users.noreply.github.com Docs/improving docs for semantics UI lib (flutter/flutter#186125) 2026-05-12 jason-simmons@users.noreply.github.com [Tool] Support glob patterns when parsing workspaces in FlutterProject (flutter/flutter#185715) 2026-05-12 nico.reiab@gmail.com docs: fix overriden -> overridden in MediaQueryData dartdoc (flutter/flutter#186323) 2026-05-12 brackenavaron@gmail.com [Test cross imports] No material in `test/foundation`, `test/gestures`, `test/semantics`, `test/services` (flutter/flutter#186144) 2026-05-12 nico.reiab@gmail.com docs: fix "tha" -> "that" typo in widget_inspector_test comment (flutter/flutter#186322) 2026-05-12 nico.reiab@gmail.com docs: Fix doubled-word typos in framework dartdoc (flutter/flutter#186319) 2026-05-12 137456488+flutter-pub-roller-bot@users.noreply.github.com Roll pub packages (flutter/flutter#186418) 2026-05-12 30870216+gaaclarke@users.noreply.github.com Bumped required mediatek vender sdk version. (flutter/flutter#186405) 2026-05-12 magder@google.com Make DeepLinkJsonFromManifestTask Gradle task build cacheable (flutter/flutter#185903) 2026-05-12 66727653+ishaq2321@users.noreply.github.com Harden dev tooling scripts against command injection and log leaks (flutter/flutter#186076) 2026-05-12 137456488+flutter-pub-roller-bot@users.noreply.github.com Roll pub packages (flutter/flutter#186274) 2026-05-12 bdero@google.com [Flutter GPU] Allow allocating multi-mip textures and overwriting specific (mip, slice) levels (flutter/flutter#185890) 2026-05-12 zhongliu88889@gmail.com [web] Fix MenuAnchor dismiss when semantics enabled (flutter/flutter#183093) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC bmparr@google.com,stuartmorgan@google.com on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

github-actions Bot added framework flutter/packages/flutter repository. See also f: labels. engine flutter/engine related. See also e: labels. a: accessibility Accessibility, e.g. VoiceOver or TalkBack. (aka a11y) platform-web Web applications specifically labels Mar 1, 2026

flutter-zl added 2 commits March 3, 2026 21:54

[web] Fix MenuAnchor dismiss when semantics enabled by flushing point…

17d5d15

…er events for non-merged nodes.

Fix SemanticsUpdateBuilderSpy.updateNode override to include mergesDe…

cef1950

…scendants parameter.

flutter-zl force-pushed the issue_167487 branch from e620ebd to cef1950 Compare March 4, 2026 05:54

flutter-zl marked this pull request as ready for review March 4, 2026 06:37

flutter-zl requested review from chunhtai and mdebbar March 4, 2026 06:37

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Comment thread engine/src/flutter/lib/ui/semantics.dart Outdated

Comment thread engine/src/flutter/lib/web_ui/lib/semantics.dart Outdated

Comment thread engine/src/flutter/lib/web_ui/lib/src/engine/pointer_binding.dart Outdated

Add doc comments for mergesDescendants and isMergedNode parameters.

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chunhtai reviewed Mar 12, 2026

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Broaden mergesDescendants to absorbedChildSemantics for tap-absorbing…

8612a6f

… containers

flutter-zl added the CICD Run CI/CD label Mar 13, 2026

Merge remote-tracking branch 'origin/master' into issue_167487

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Merge remote-tracking branch 'origin/master' into issue_167487

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flutter-zl added 4 commits April 2, 2026 22:01

Merge remote-tracking branch 'origin/master' into issue_167487

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Merge branch 'master' of github.com:flutter/flutter into issue_167487

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[web] Fix MenuAnchor dismiss by making TapRegionSurface listen to Sem…

c105adb

…anticsAction.tap

Remove unrelated doc comment addition from engine semantics.dart

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github-actions Bot removed the a: accessibility Accessibility, e.g. VoiceOver or TalkBack. (aka a11y) label Apr 6, 2026

flutter-zl requested a review from chunhtai May 11, 2026 20:56

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[web] Rename to getRectOfSemanticsNodeInViewCoordinates

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[web] Move testWidgets to semantics_binding_test.dart

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