Implements engine-side declarative pointer event handling for semantics. #176974

flutter-zl · 2025-10-13T21:39:50Z

Implements engine-side declarative pointer event handling for semantics.

Framework-side to be implemented in next PR.

Before change
https://dialog-dismiss-before.web.app/

Click on the "Show Dialog" button.
Click anywhere inside the dialog that is not a form field.
Observe the dialog being dismissed.

After change
https://dialog-dimiss-after.web.app/

Click on the "Show Dialog" button.
Click anywhere inside the dialog that is not a form field.
Observe the dialog not dismissed.

gemini-code-assist

Code Review

This pull request effectively fixes an issue where dialogs on the web could be prematurely dismissed when semantics are enabled. The root cause was that non-interactive semantic leaf nodes were incorrectly intercepting pointer events.

The fix introduces a more nuanced policy for determining which semantic nodes accept pointer events:

Route-scoped containers (like dialogs) now accept pointer events to function as a barrier.
Leaf nodes only accept pointer events if they are interactive (e.g., buttons, text fields).

This change is well-supported by a comprehensive set of new unit tests that verify the behavior of various interactive and non-interactive nodes. The implementation is clear and directly addresses the problem. I have a couple of suggestions to further improve robustness and test maintainability.

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

engine/src/flutter/lib/web_ui/test/engine/semantics/semantics_test.dart

mdebbar · 2025-10-14T14:26:19Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+    return semanticsObject.isTappable ||
+        semanticsObject.isButton ||
+        semanticsObject.isCheckable ||
+        semanticsObject.flags.isTextField ||
+        semanticsObject.flags.isLink ||
+        semanticsObject.flags.isSlider ||
+        semanticsObject.isIncrementable;


All of these have their own Semantics role or behavior (except isSlider [1]). Let's override the acceptsPointerEvents in the corresponding classes.

[1] It looks like semantic sliders are not implemented? So let's not worry about it now.

Implemented engine-side declarative pointer event handling for semantics based on discussion. Please review.

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

Enhanced acceptsPointerEvents with: - Multi-tier policy documentation (4 tiers) - Tier 1: Explicit behaviors (Tappable, TextField, etc.) - Tier 2: Framework declaration (TODO for future SemanticsHitTestBehavior) - Tier 3: Route-scoped containers fallback (current fix) - Tier 4: Default transparent leaf nodes The fallback ensures: - Immediate bug fix for dialog dismissal - Backward compatibility during framework transition - Support for third-party packages - Graceful degradation for custom widgets Prepared for future framework PR that will add SemanticsHitTestBehavior enum for declarative control over pointer event handling. Related: #149001 Discussion: #176974

chunhtai · 2025-10-17T18:26:37Z

engine/src/flutter/lib/ui/semantics.dart

@@ -1156,6 +1156,34 @@ enum Tristate {
  }
 }

+/// Describes how a semantic node should behave during hit testing.
+///
+/// This enum is used by the web engine to determine whether semantic elements


This will likely to be used by other platform as well, we should make the language platform neutral
#177025
#177024

Thanks for reviewing. I updated the PR accordingly.

chunhtai · 2025-10-17T18:28:07Z

engine/src/flutter/lib/ui/semantics.dart

+enum SemanticsHitTestBehavior {
+  /// The semantic element is opaque to hit testing, consuming any pointer
+  /// events within its bounds and preventing them from reaching elements
+  /// behind it.


is this blocking child or sibling in hittest order? or both? should document this more clearly

Thanks for reviewing. I updated the PR accordingly.

chunhtai · 2025-10-17T18:28:57Z

engine/src/flutter/lib/ui/semantics.dart

@@ -1792,12 +1820,20 @@ abstract class SemanticsUpdateBuilder {
  /// not use this argument should use other ways to communicate validation
  /// errors to the user, such as embedding validation error text in the label.
  ///
+  /// The `hitTestBehavior` describes how this node should behave during hit
+  /// testing. If null, the platform will infer appropriate behavior based on
+  /// other semantic properties. This is primarily used by the web platform to


same for the comment here, should be platform neutral

what's the infer behavior? do they inherited from the parent?

Thanks for reviewing. I updated the PR accordingly.

chunhtai · 2025-10-17T18:31:34Z

engine/src/flutter/lib/ui/semantics.dart

@@ -1792,12 +1820,20 @@ abstract class SemanticsUpdateBuilder {
  /// not use this argument should use other ways to communicate validation
  /// errors to the user, such as embedding validation error text in the label.
  ///
+  /// The `hitTestBehavior` describes how this node should behave during hit
+  /// testing. If null, the platform will infer appropriate behavior based on


instead of using null, consider give it a enum SemanticsHitTestBehavior.defer and makes it the default

Thanks for reviewing. I updated the PR accordingly.

chunhtai · 2025-10-17T18:32:08Z

engine/src/flutter/lib/ui/semantics.dart

@@ -1913,6 +1949,7 @@ base class _NativeSemanticsUpdateBuilder extends NativeFieldWrapperClass1
    SemanticsRole role = SemanticsRole.none,
    required List<String>? controlsNodes,
    SemanticsValidationResult validationResult = SemanticsValidationResult.none,
+    SemanticsHitTestBehavior? hitTestBehavior,


should remove nullable and make required

Thanks for reviewing. I updated the PR accordingly.

chunhtai · 2025-10-17T18:40:49Z

engine/src/flutter/lib/ui/semantics.dart

+  ///
+  /// This is the default behavior for non-interactive semantic nodes.
+  ///
+  /// On the web, this results in `pointer-events: none` CSS property.


In framework transparent means this node receives hittest, but won't block the silbing and child behind it from receiving hittest

Thanks for reviewing. I updated the PR accordingly.

In framework transparent means this node receives hittest, but won't block the silbing and child behind it from receiving hittest

I think you meant "translucent"?

flutter/packages/flutter/lib/src/rendering/proxy_box.dart

Lines 144 to 158 in 542705c

/// How to behave during hit tests.

enum HitTestBehavior {

/// Targets that defer to their children receive events within their bounds

/// only if one of their children is hit by the hit test.

deferToChild,

/// Opaque targets can be hit by hit tests, causing them to both receive

/// events within their bounds and prevent targets visually behind them from

/// also receiving events.

opaque,

/// Translucent targets both receive events within their bounds and permit

/// targets visually behind them to also receive events.

translucent,

}

"transparent" is defined in platform view behaviors:

flutter/packages/flutter/lib/src/rendering/platform_view.dart

Lines 19 to 32 in 542705c

enum PlatformViewHitTestBehavior {

/// Opaque targets can be hit by hit tests, causing them to both receive

/// events within their bounds and prevent targets visually behind them from

/// also receiving events.

opaque,

/// Translucent targets both receive events within their bounds and permit

/// targets visually behind them to also receive events.

translucent,

/// Transparent targets don't receive events within their bounds and permit

/// targets visually behind them to receive events.

transparent,

}

"opaque" matches pointer-events: all on the web.

"transparent" matches pointer-events: none on the web.

"translucent" (which is what you're describing) is not possible on web AFAICT.

Good catch. I updated the PR accordingly.

chunhtai · 2025-10-17T18:43:57Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+  ///
+  /// The decision follows a multi-tier policy:
+  ///
+  /// **Tier 1: Explicit Behaviors** - Behaviors attached to this role can


Declaration should probably come first before this. Also I think you meant Implicit behaviors? since the behavior is inferred from semantics behavior/role

also ideally we should infer the SemanticsHitTestBehavior from the framework side if not provided. That way the platform just need to deal with SemanticsHitTestBehavior

Thanks for reviewing. I updated the PR accordingly.

Declaration should probably come first before this.

This part of the comment was not addressed. When the framework says the node is transparent, we should treat it as transparent. It becomes really confusing when users set a button to transparent and notice that the button is still receiving clicks and blocking hit testing.

If we think it's a bad idea to allow interactive nodes to be transparent, then we should make that state illegal at the framework level. IMO the engine should just follow what the framework dictates.

Good catch. I thought it is about code style. I updated the PR accordingly.

chunhtai · 2025-10-17T18:44:53Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+  /// [ui.SemanticsHitTestBehavior], it will be respected here. This allows
+  /// declarative control over pointer event handling from the framework layer.
+  ///
+  /// **Tier 3: Route-Scoped Containers** - Containers with [scopesRoute] set


This should be handled in framework by wrapping ModalRoute with SemanticsHitTestBehavior

You're right that framework should handle this. Our architecture fully supports that. When framework provides explicit values, engine just executes them (Tier 1). Engine inference is only a backward-compatible fallback (Tier 2) because popular packages like awesome_dialog don't know about SemanticsHitTestBehavior yet. Engine inference means they work immediately.

chunhtai · 2025-10-17T18:45:39Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+  /// preventing clicks from escaping to underlying modal barriers. This is
+  /// the current fix for issue #149001.
+  ///
+  /// **Tier 4: Default Transparent** - Leaf nodes without interactive behaviors


we could also handle this on the framework side by inferring SemanticsHitTestBehavior if not provided

You're right that framework should handle this. Our architecture fully supports that. When framework provides explicit values, engine just executes them (Tier 1). Engine inference is only a backward-compatible fallback (Tier 2) because popular packages like awesome_dialog don't know about SemanticsHitTestBehavior yet. Engine inference means they work immediately.

chunhtai · 2025-10-20T21:26:21Z

engine/src/flutter/lib/ui/semantics.dart

+  /// Platform implementations:
+  ///  * On the web, this results in `pointer-events: none` CSS property.
+  ///
+  /// This is the default behavior for non-interactive semantic nodes when the


this paragraph should probably be in defer enum instead, and also mention this is web's default behavior if we want to include this info. (we don't know what other platform will do yet)

Great suggestion. I updated the documentation.

chunhtai · 2025-10-20T21:31:10Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/incrementable.dart

  }

+  @override
+  bool get acceptsPointerEvents => true;


This is unfortunate name collisions, should make it something like shouldAcceptsPointerEvents.

acceptsPointerEvents already exists in abstract class SemanticBehavior and abstract class SemanticBehavior. Please check https://github.com/flutter/flutter/blob/master/engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart. do we want to change one of them to shouldAcceptsPointerEvents?

we should rename this getter for every classes, it shouldn't be a problem since these are not public

Thanks for the explanation. I updated the code.

chunhtai · 2025-10-20T21:32:30Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+  /// - Route-scoped containers (dialogs, bottom sheets)
+  /// - Default transparent for non-interactive leaf nodes
+  ///
+  /// This approach allows framework full control when specified, with intelligent


Suggested change

/// This approach allows framework full control when specified, with intelligent

/// This approach allows framework full control when specified, with reasonable

should tune down the tone a bit

Great suggestion. I updated the documentation.

chunhtai · 2025-10-20T21:34:01Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+      case ui.SemanticsHitTestBehavior.defer:
+        // This case should never be reached because defer is handled in
+        // acceptsPointerEvents before calling this method.
+        assert(false, 'defer should be handled by _inferAcceptsPointerEvents');


consider inline this switch case directly in acceptsPointerEvents body so that we don't need this assert

Great suggestion. I updated the code.

chunhtai · 2025-10-20T21:36:04Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+
+  /// Infers whether pointer events should be accepted based on semantic properties.
+  ///
+  /// This method is called when [ui.SemanticsHitTestBehavior.defer] is set,


consider remove this paragraph and use assert(hitTestBehavior == ui.SemanticsHitTestBehavior.defer) to explain the assumption

Great suggestion. I updated the code.

chunhtai · 2025-10-20T21:39:47Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart

+    // from passing through to the modal barrier underneath.
    if (semanticsObject.hasChildren) {
-      return false;
+      return semanticsObject.scopesRoute;


this should be set from the framework side instead of using inferring here. The reason being that we don't want every platform has to duplicate this logic. ideally, platform inferring should be as less as possible.

The intention is to let packages like https://pub.dev/packages/awesome_dialog which has not implemented our change to have the fix.

In general, it will be their responsibility to opt in, but in this case as long as this is wrapped in

flutter/packages/flutter/lib/src/widgets/routes.dart

Line 2330 in 27d070b

_modalScope = OverlayEntry(

All the route/dialog should get this automaticially

Thanks for the explanation. I updated the code.

…vior naming collision

chunhtai

LGTM

chunhtai · 2025-10-23T18:28:12Z

engine/src/flutter/lib/web_ui/lib/src/engine/semantics/incrementable.dart

+      ui.SemanticsHitTestBehavior.opaque => true,
+      ui.SemanticsHitTestBehavior.transparent => false,
+      _ => true,


Suggested change

ui.SemanticsHitTestBehavior.opaque => true,

ui.SemanticsHitTestBehavior.transparent => false,

_ => true,

ui.SemanticsHitTestBehavior.transparent => false,

_ => true,

missed this

good catch. Updated.

…or semantics. (flutter/flutter#176974)

Roll Flutter from 75004a639ae4 to cb18290fa45e (48 revisions) flutter/flutter@75004a6...cb18290 2025-10-24 [email protected] Remove unnecessary `deprecated` withOpacity in `text_button.0.dart‎` in examples (flutter/flutter#177374) 2025-10-24 [email protected] Roll Packages from 9ec29b6 to 53d6138 (3 revisions) (flutter/flutter#177502) 2025-10-24 [email protected] Roll Dart SDK from d3248b00f545 to a0480f399f8f (1 revision) (flutter/flutter#177498) 2025-10-24 [email protected] Roll Skia from a47931d09585 to 3ed332b77bec (3 revisions) (flutter/flutter#177487) 2025-10-24 [email protected] Roll Abseil to Chromium's 5b92b04a2e (based on Abseil commit fc4481e968) (flutter/flutter#177059) 2025-10-24 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Reverts "Enhance PR template with changelog and impact details (#177333)" (#177468)" (flutter/flutter#177499) 2025-10-24 [email protected] Document DropdownMenu showTrailingIcon and decorationBuilder interaction (flutter/flutter#177488) 2025-10-24 [email protected] Roll Dart SDK from 4a65fb890852 to d3248b00f545 (1 revision) (flutter/flutter#177486) 2025-10-24 [email protected] Fix bottom sheet Semantics route label for mismatched platforms (flutter/flutter#177094) 2025-10-24 [email protected] Roll Skia from eba11de00d5b to a47931d09585 (5 revisions) (flutter/flutter#177481) 2025-10-24 [email protected] Fix Dialog Semantics label and flags for mismatched platforms (flutter/flutter#176781) 2025-10-24 [email protected] Fix drawer Semantics for mismatched platforms (flutter/flutter#177095) 2025-10-24 [email protected] Roll Dart SDK from f7751ccea102 to 4a65fb890852 (2 revisions) (flutter/flutter#177480) 2025-10-23 [email protected] Change the root path of the license crawl to engine/src (flutter/flutter#177352) 2025-10-23 [email protected] [Material] Change default mouse cursor of buttons to basic arrow instead of click (except on web) (flutter/flutter#171796) 2025-10-23 [email protected] [Desktop] Propagate SemanticsNode::identifier to AXPlatformNodeDelegate::AuthorUniqueId (flutter/flutter#175405) 2025-10-23 [email protected] Roll Skia from 59ef57f4104e to eba11de00d5b (5 revisions) (flutter/flutter#177461) 2025-10-23 [email protected] Roll customer tests (flutter/flutter#177409) 2025-10-23 [email protected] Update CHANGELOG 3.35.7 notes (flutter/flutter#177463) 2025-10-23 [email protected] Marks Mac module_uiscene_test_ios to be unflaky (flutter/flutter#177378) 2025-10-23 [email protected] Allow empty dart defines in `flutter assemble` (flutter/flutter#177198) 2025-10-23 [email protected] Roll Packages from d113bbc to 9ec29b6 (12 revisions) (flutter/flutter#177455) 2025-10-23 [email protected] Implements engine-side declarative pointer event handling for semantics. (flutter/flutter#176974) 2025-10-23 [email protected] Fix the platform name of the windowing_test target for macOS in ci.yaml (flutter/flutter#177472) 2025-10-23 98614782+auto-submit[bot]@users.noreply.github.com Reverts "Enhance PR template with changelog and impact details (#177333)" (flutter/flutter#177468) 2025-10-23 [email protected] Change Flutter APIs to use spans (flutter/flutter#177272) 2025-10-23 [email protected] Roll Dart SDK from 020988602772 to f7751ccea102 (4 revisions) (flutter/flutter#177449) 2025-10-23 [email protected] [macOS] Implement regular window (flutter/flutter#176361) 2025-10-23 [email protected] Enhance PR template with changelog and impact details (flutter/flutter#177333) 2025-10-23 [email protected] Roll Skia from 6e6acf6644ef to 59ef57f4104e (2 revisions) (flutter/flutter#177436) 2025-10-23 [email protected] Add directional static members to AlignmentGeometry. (flutter/flutter#176571) 2025-10-23 [email protected] Roll ICU from 1b2e3e8a421e to ff35c4f9df23 (5 revisions) (flutter/flutter#177434) 2025-10-23 [email protected] Adds a new CI build for Linux host DDM-enabled artifacts (flutter/flutter#177252) 2025-10-23 [email protected] Roll Skia from 920cdcadd74c to 6e6acf6644ef (1 revision) (flutter/flutter#177432) 2025-10-23 [email protected] Roll Skia from 8cd449e4953b to 920cdcadd74c (6 revisions) (flutter/flutter#177426) 2025-10-23 [email protected] Added ahem license (flutter/flutter#177423) 2025-10-23 [email protected] Roll Dart SDK from 75f6ccb9bdc5 to 020988602772 (1 revision) (flutter/flutter#177421) 2025-10-23 [email protected] [web] Set `pointer-events: none` for img-element-backed images (flutter/flutter#177418) 2025-10-22 [email protected] Remove the x64 version of build_ios_framework_module_test (flutter/flutter#177136) 2025-10-22 [email protected] Fix accessibility events not being correctly translated to ATK (flutter/flutter#176991) 2025-10-22 [email protected] Roll Skia from b55bd60ed95b to 8cd449e4953b (8 revisions) (flutter/flutter#177405) 2025-10-22 [email protected] Roll Dart SDK from c23010c4f9e6 to 75f6ccb9bdc5 (4 revisions) (flutter/flutter#177399) 2025-10-22 [email protected] Fixes crash when adding and removing mulitple page-based route (flutter/flutter#177338) 2025-10-22 [email protected] Move child parameter to end of RefreshIndicator constructor (flutter/flutter#177019) 2025-10-22 [email protected] refactor: migrate OpenUpwardsPageTransitionsBuilder to widgets (flutter/flutter#177080) 2025-10-22 [email protected] Delete stray 'text' file (flutter/flutter#177355) ...

…pply to ModalRoute (#177570) Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: #149001 Engine work: #176974

…get and apply to ModalRoute (#177570)" (#178744)  Reverts: #177570   Initiated by: chingjun   Reason for reverting: Broke internal tests.   Original PR Author: flutter-zl   Reviewed By: {chunhtai}   This change reverts the following previous change: Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: #149001 Engine work: #176974  Co-authored-by: auto-submit[bot] <[email protected]>

…pply to ModalRoute (flutter#177570) Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974

…get and apply to ModalRoute (flutter#177570)" (flutter#178744)  Reverts: flutter#177570   Initiated by: chingjun   Reason for reverting: Broke internal tests.   Original PR Author: flutter-zl   Reviewed By: {chunhtai}   This change reverts the following previous change: Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974  Co-authored-by: auto-submit[bot] <[email protected]>

…pply to ModalRoute (flutter#177570) Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974

…get and apply to ModalRoute (flutter#177570)" (flutter#178744)  Reverts: flutter#177570   Initiated by: chingjun   Reason for reverting: Broke internal tests.   Original PR Author: flutter-zl   Reviewed By: {chunhtai}   This change reverts the following previous change: Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974  Co-authored-by: auto-submit[bot] <[email protected]>

…cs. (flutter#176974) Implements engine-side declarative pointer event handling for semantics. Framework-side to be implemented in next PR. Fixes flutter#149001. **Before change** https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. **After change** https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed.

…pply to ModalRoute (flutter#177570) Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974

…get and apply to ModalRoute (flutter#177570)" (flutter#178744)  Reverts: flutter#177570   Initiated by: chingjun   Reason for reverting: Broke internal tests.   Original PR Author: flutter-zl   Reviewed By: {chunhtai}   This change reverts the following previous change: Fix premature dialog dismissal on Flutter Web when semantics are enabled by correctly propagating hitTestBehavior through the semantics pipeline and declaring modal routes as opaque to pointer events. Before change https://dialog-dismiss-before.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog being dismissed. After change https://dialog-dimiss-after.web.app/ Click on the "Show Dialog" button. Click anywhere inside the dialog that is not a form field. Observe the dialog not dismissed. Fixes: flutter#149001 Engine work: flutter#176974  Co-authored-by: auto-submit[bot] <[email protected]>

Fix premature dialog dismissal on Web when semantics enabled

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github-actions bot added engine flutter/engine related. See also e: labels. a: accessibility Accessibility, e.g. VoiceOver or TalkBack. (aka a11y) platform-web Web applications specifically labels Oct 13, 2025

gemini-code-assist bot reviewed Oct 13, 2025

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flutter-zl added 2 commits October 13, 2025 15:03

Add checkable support and refactor tests per review feedback

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Merge remote-tracking branch 'origin/master' into dialog_1009

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engine/src/flutter/lib/web_ui/lib/src/engine/semantics/semantics.dart Outdated Show resolved Hide resolved

Removed explicit flag checks from SemanticRole.acceptsPointerEvents

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flutter-zl requested a review from mdebbar October 15, 2025 05:46

flutter-zl force-pushed the dialog_1009 branch from a5c665d to 69dfd15 Compare October 17, 2025 05:18

Implements engine-side declarative pointer event handling for semantics

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flutter-zl changed the title ~~Fix premature dialog dismissal on Web when semantics enabled~~ Implements engine-side declarative pointer event handling for semantics. Oct 17, 2025

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flutter-zl added 2 commits October 19, 2025 21:52

Address PR review comments on SemanticsHitTestBehavior architecture

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Address review feedback: framework declaration takes precedence

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flutter-zl requested a review from chunhtai October 20, 2025 19:07

flutter-zl added 3 commits October 20, 2025 12:13

Merge remote-tracking branch 'origin/master' into dialog_1009

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Add hitTestBehavior parameter to C++ updateNode

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Add hitTestBehavior parameter

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github-actions bot added the framework flutter/packages/flutter repository. See also f: labels. label Oct 20, 2025

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update documentation

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flutter-zl requested a review from chunhtai October 21, 2025 18:54

Remove scopesRoute engine inference and fix SemanticRole/SemanticBeha…

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…vior naming collision

flutter-zl requested a review from chunhtai October 23, 2025 18:23

chunhtai approved these changes Oct 23, 2025

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Simplified the switch statements

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flutter-zl added this pull request to the merge queue Oct 23, 2025

Merged via the queue into master with commit 26766ac Oct 23, 2025
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flutter-zl deleted the dialog_1009 branch October 23, 2025 21:59

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Oct 24, 2025

26766ac86 Implements engine-side declarative pointer event handling f…

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…or semantics. (flutter/flutter#176974)

This was referenced Oct 24, 2025

Roll Flutter from 75004a639ae4 to 67068ee0fe96 (44 revisions) flutter/packages#10291

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Roll Flutter from 75004a639ae4 to 9e1bf394ff3a (45 revisions) flutter/packages#10294

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engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Oct 24, 2025

26766ac86 Implements engine-side declarative pointer event handling f…

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…or semantics. (flutter/flutter#176974)

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Roll Flutter from 75004a639ae4 to 865f4431bd3d (46 revisions) flutter/packages#10296

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engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Oct 24, 2025

26766ac86 Implements engine-side declarative pointer event handling f…

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…or semantics. (flutter/flutter#176974)

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Roll Flutter from 75004a639ae4 to b1ee775f45cb (47 revisions) flutter/packages#10297

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engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Oct 24, 2025

26766ac86 Implements engine-side declarative pointer event handling f…

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…or semantics. (flutter/flutter#176974)

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Roll Flutter from 75004a639ae4 to cb18290fa45e (48 revisions) flutter/packages#10299

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engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Oct 24, 2025

26766ac86 Implements engine-side declarative pointer event handling f…

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…or semantics. (flutter/flutter#176974)

Piinks mentioned this pull request Oct 27, 2025

Flutter Notable Commits - 2025 #161460

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flutter-zl mentioned this pull request Oct 28, 2025

Add framework-side hitTestBehavior support for Semantics widget and apply to ModalRoute #177570

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auto-submit bot mentioned this pull request Nov 18, 2025

Reverts "Add framework-side hitTestBehavior support for Semantics widget and apply to ModalRoute (#177570)" #178744

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	/// How to behave during hit tests.
	enum HitTestBehavior {
	/// Targets that defer to their children receive events within their bounds
	/// only if one of their children is hit by the hit test.
	deferToChild,

	/// Opaque targets can be hit by hit tests, causing them to both receive
	/// events within their bounds and prevent targets visually behind them from
	/// also receiving events.
	opaque,

	/// Translucent targets both receive events within their bounds and permit
	/// targets visually behind them to also receive events.
	translucent,
	}

	enum PlatformViewHitTestBehavior {
	/// Opaque targets can be hit by hit tests, causing them to both receive
	/// events within their bounds and prevent targets visually behind them from
	/// also receiving events.
	opaque,

	/// Translucent targets both receive events within their bounds and permit
	/// targets visually behind them to also receive events.
	translucent,

	/// Transparent targets don't receive events within their bounds and permit
	/// targets visually behind them to receive events.
	transparent,
	}

	/// This approach allows framework full control when specified, with intelligent
	/// This approach allows framework full control when specified, with reasonable

Implements engine-side declarative pointer event handling for semantics. #176974

Implements engine-side declarative pointer event handling for semantics. #176974

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flutter-zl commented Oct 13, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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mdebbar Oct 20, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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chunhtai Oct 20, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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flutter-zl commented Oct 13, 2025 •

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