[material_ui] Ensure textScaler is taken into account for SnackBar action overflow by matasb-google · Pull Request #12737 · flutter/packages

matasb-google · 2026-09-03T12:52:29Z

Port of flutter/flutter#181959 to flutter/packages as part of the Material decoupling effort (flutter/flutter#188444).

Ensure textScalling is taken into account for Sizing overflow.

Fixes flutter/flutter#192232
Fixes flutter/flutter#181959
Part of flutter/flutter#188444

Description

Ensure textScalling is taken into account for Sizing overflow: passes MediaQuery.textScalerOf(context) to actionTextPainter so that actionAndIconWidth properly scales with accessibility text scaling.
Removes SizedBox(width: snackBarWidth * 0.4) when the action overflows, eliminating unintended blank space on the right of multi-line content.
Adds unit tests in snack_bar_test.dart verifying textScaler overflow calculation and layout.
Adds pending changelog entry.

Pre-Review Checklist

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

Regular contributors who have demonstrated familiarity with the repository guidelines only need to comment if the PR is not auto-exempted by repo tooling. ↩ ↩²

…tion overflow Port of flutter/flutter#181959 to flutter/packages as part of the Material decoupling effort (flutter/flutter#188444). - Ensure MediaQuery's textScaler is passed to actionTextPainter so that action button width calculation scales appropriately. - Remove SizedBox(width: snackBarWidth * 0.4) when action overflows, eliminating unintended blank space on the right of multi-line content. - Add unit tests verifying textScaler overflow calculation and layout. - Add pending changelog entry.

gemini-code-assist

Code Review

This pull request updates the SnackBar implementation to respect the MediaQuery's TextScaler when calculating action overflow, and removes the unnecessary 40% blank right spacing in multi-line layouts. It also adds corresponding widget tests to verify these behaviors. There are no review comments, so I have no feedback to provide.

matasb-google · 2026-09-07T15:04:01Z

@Piinks This has now been ported over from flutter/flutter#181959 with unit tests and pending changelog following #188444. Ready for review!

Piinks

Thanks for porting this over and adding tests! :)
Some tests are failing, but I left info on how to fix below:

Piinks · 2026-09-08T17:18:06Z

              if (!willOverflowAction) ...maybeActionAndIcon,
-              if (willOverflowAction) SizedBox(width: snackBarWidth * 0.4),
            ],


Because default padding sets end: 0 when widget.action != null, removing the SizedBox leaves Row 1 with 0px right padding when the action wraps to Row 2. We should retain horizontalPadding for the content:

Suggested change

if (!willOverflowAction) ...maybeActionAndIcon,

if (willOverflowAction) SizedBox(width: snackBarWidth * 0.4),

],

if (!willOverflowAction) ...maybeActionAndIcon,

if (willOverflowAction && widget.padding == null)

SizedBox(width: horizontalPadding),

I think the suggested change makes sense. Please fix. When custom padding is provided, we should respect it instead of still using the default horizontalPadding.

We should also add a unit test to verify the SnackBar.padding is respected.

Done in 1e622ce — gated the spacer SizedBox on widget.padding == null and added the SnackBar respects custom padding when action overflows unit test.

Piinks · 2026-09-08T17:19:13Z

+
+    // Verify there is no SizedBox with width equal to 40% of snackBarWidth.
+    expect(
+      find.byWidgetPredicate(


snackBarWidth is screenWidth - margin = 470, so the old sized box was 188px, not screenWidth * 0.4 (200px). This predicate would have returned false and passed even on unfixed code. Consider asserting the content's right padding or layout width directly instead.

Piinks · 2026-09-08T17:19:55Z

      expect(find.text('bar2'), findsNothing);
    }
  }
+


These tests were placed inside _testSnackBarDismiss (outside main()), causing SnackBar dismiss test to throw Bad state: Can't call test() once tests have begun running.. Please move them into void main() { ... } before line 4400.

Piinks · 2026-09-08T17:19:56Z

+    Widget buildSnackBar({required TextScaler textScaler}) {
+      return MaterialApp(
+        home: MediaQuery(
+          data: MediaQueryData(size: const Size(400, 800), textScaler: textScaler),


On a 400px screen (snackBarWidth = 370), 'Action Label' (~97px) exceeds the 25% threshold (92.5px) and overflows even with TextScaler.noScaling, failing line 4482. Use Size(800, 600) so it fits on line 1 at 1.0x scale and overflows at 3.0x scale:

Suggested change

data: MediaQueryData(size: const Size(400, 800), textScaler: textScaler),

data: MediaQueryData(size: const Size(800, 600), textScaler: textScaler),

… horizontalPadding

Piinks

LGTM thank you! Let me get a second reviewer for this

QuncCccccc

Overall looks good. Just left a few comments.

QuncCccccc · 2026-09-10T19:05:44Z

              if (!willOverflowAction) ...maybeActionAndIcon,
-              if (willOverflowAction) SizedBox(width: snackBarWidth * 0.4),
            ],


I think the suggested change makes sense. Please fix. When custom padding is provided, we should respect it instead of still using the default horizontalPadding.

QuncCccccc · 2026-09-10T19:06:28Z

              if (!willOverflowAction) ...maybeActionAndIcon,
-              if (willOverflowAction) SizedBox(width: snackBarWidth * 0.4),
            ],


We should also add a unit test to verify the SnackBar.padding is respected.

Only insert the trailing spacer SizedBox when the default padding is used, since a caller-supplied padding already applies its own end inset. Adds a unit test covering asymmetric SnackBar.padding with an overflowing action.

QuncCccccc

LGTM. Thank you!

QuncCccccc · 2026-10-06T21:30:55Z

Hi! Seems Dashboard Checks has some failures, could you help fix them?

Analyzing material_ui...

   info - test/snack_bar_test.dart:4444:11 - Omit the type annotation on a local variable when the type is obvious. Try removing the type annotation. - omit_obvious_local_variable_types
   info - test/snack_bar_test.dart:4495:11 - Omit the type annotation on a local variable when the type is obvious. Try removing the type annotation. - omit_obvious_local_variable_types
   info - test/snack_bar_test.dart:4496:11 - Omit the type annotation on a local variable when the type is obvious. Try removing the type annotation. - omit_obvious_local_variable_types

matasb-google · 2026-10-09T16:25:52Z

@QuncCccccc Fixed the 3 omit_obvious_local_variable_types lints in ddaff91 and verified with dart analyze --fatal-infos. Thank you!

flutter/packages@d8d9e97...a1ed23c 2026-10-13 [email protected] [material_ui] Clarify Slider labels for continuous sliders (flutter/packages#13121) 2026-10-12 [email protected] [in_app_purchase_storekit] Remove availability checks below the package minimum iOS 13 and macOS 10.15 (flutter/packages#13217) 2026-10-12 [email protected] [google_sign_in] Convert unit tests to Kotlin (flutter/packages#13000) 2026-10-12 [email protected] [vector_graphics_compiler] Support SVG alpha masks (mask-type="alpha") (flutter/packages#13025) 2026-10-11 [email protected] [camera_platform_interface] Add zero-shutter-lag API (flutter/packages#12996) 2026-10-10 [email protected] [material_ui] Ensure textScaler is taken into account for SnackBar action overflow (flutter/packages#12737) 2026-10-10 [email protected] [material_ui] Add more 0x0 size tests part 14 (flutter/packages#13107) 2026-10-10 [email protected] [cupertino_ui] Fix CupertinoPicker throwing when disposed during the tap-to-select animation (flutter/packages#13012) 2026-10-09 [email protected] Roll Flutter (stable) from 5fc3468 to abaf9c5 (3 revisions) (flutter/packages#13186) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages-flutter-autoroll Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Flutter: 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 p: material_ui triage-design Should be looked at in design triage labels Sep 3, 2026

gemini-code-assist Bot reviewed Sep 3, 2026

View reviewed changes

matasb-google mentioned this pull request Sep 3, 2026

Update snack_bar.dart flutter/flutter#181959

Closed

9 tasks

Piinks added the CICD Run CI/CD label Sep 8, 2026

Piinks reviewed Sep 8, 2026

View reviewed changes

Address review comments: move tests to main, fix scale sizing, retain…

88772d6

… horizontalPadding

flutter-dashboard Bot removed the CICD Run CI/CD label Sep 9, 2026

Piinks approved these changes Sep 9, 2026

View reviewed changes

QuncCccccc reviewed Sep 10, 2026

View reviewed changes

Respect custom SnackBar.padding when action overflows

1e622ce

Only insert the trailing spacer SizedBox when the default padding is used, since a caller-supplied padding already applies its own end inset. Adds a unit test covering asymmetric SnackBar.padding with an overflowing action.

Piinks requested a review from QuncCccccc September 24, 2026 21:40

QuncCccccc approved these changes Oct 2, 2026

View reviewed changes

QuncCccccc added the CICD Run CI/CD label Oct 2, 2026

Merge branch 'main' into port-pr-181959-snackbar

4fb4937

flutter-dashboard Bot removed the CICD Run CI/CD label Oct 2, 2026

QuncCccccc added the CICD Run CI/CD label Oct 2, 2026

Omit obvious local variable types in snack_bar_test.dart

ddaff91

flutter-dashboard Bot removed the CICD Run CI/CD label Oct 9, 2026

QuncCccccc added CICD Run CI/CD autosubmit Merge PR when tree becomes green via auto submit App labels Oct 9, 2026

auto-submit Bot merged commit b3d80fe into flutter:main Oct 10, 2026
13 checks passed

matasb-google deleted the port-pr-181959-snackbar branch October 10, 2026 17:46

	data: MediaQueryData(size: const Size(400, 800), textScaler: textScaler),
	data: MediaQueryData(size: const Size(800, 600), textScaler: textScaler),

Conversation

matasb-google commented Sep 3, 2026

Description

Pre-Review Checklist

Footnotes

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

matasb-google commented Sep 7, 2026

Uh oh!

Piinks left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

matasb-google Oct 1, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Piinks left a comment

Choose a reason for hiding this comment

Uh oh!

QuncCccccc left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

QuncCccccc left a comment

Choose a reason for hiding this comment

Uh oh!

QuncCccccc commented Oct 6, 2026

Uh oh!

matasb-google commented Oct 9, 2026

Uh oh!

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

matasb-google Oct 1, 2026 •

edited

Loading