SnackBar with action no longer auto-dismiss #173084

QuncCccccc · 2025-07-31T23:16:06Z

This PR updated the default behavior for Snackbar with action:

SnackBars no longer auto-dismiss if SnackBar.action is not null.
To override the default behavior, this PR added a property persist for SnackBar.

Pre-launch Checklist

I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
I read the [Tree Hygiene] wiki page, which explains my responsibilities.
I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
I signed the [CLA].
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is [test-exempt].
I followed the [breaking change policy] and added [Data Driven Fixes] where supported.
All existing and new tests are passing.

gemini-code-assist

Code Review

This pull request correctly implements the dismissible property for SnackBar to control whether it dismisses after a timeout. The implementation is straightforward, and the new functionality is well-covered by a new test case. I've found one minor issue with a leftover debug print statement that should be removed.

packages/flutter/lib/src/material/scaffold.dart

victorsanni

I'm wondering if the default behavior of a Snackbar with an action still timing out should be kept. Although changing the default will be a breaking change.

victorsanni · 2025-08-01T17:59:52Z

packages/flutter/lib/src/material/snack_bar.dart

+  ///
+  /// Defaults to true. If false, the snack bar is still there even after the
+  /// timeout, unless the user taps the action button or the close icon.
+  final bool dismissible;


Not sure if dismissible is the right term, since tapping the action button dismisses the snackbar even when dismissible is false. I think the timeout vs. non-timeout is what makes this API distinctive.

Thanks for helping review the change! Then maybe dismissAfterTimeout or autoDismiss? I'm bad at naming. Any better names are welcome!

I'm wondering if the default behavior of a Snackbar with an action still timing out should be kept.

The main concern is the breaking change. If we change the default, we might need to inform developers to change all existing use cases. Just checked the specs on M3 website, it mentioned auto-dismiss though. Maybe we can disable the auto-dismiss if action/close icon is not null? WDYT @victorsanni @chunhtai :) ?

Any better names are welcome!

Maybe something like canTimeout or shouldTimeout?

Maybe we can disable the auto-dismiss if action/close icon is not null?

The spec says "Snackbars with actions should remain on the screen until the user takes an action on the snackbar, or dismisses it." So we might have to change the default and inform developers. I opened #173127 to check how bad the breaking change will be.

But irrespective of that I think the new API is definitely useful.

I'm confused by the spec. I read through it and in some places it suggests that the snackbar always dismisses by itself, even with an action. Maybe there's someone material to clarify?

maybe persist?

If the spec is contradicting itself, you can file an issue using the template from here https://buganizer.corp.google.com/issues/394084228

Filed a ticket: b/438264879

I just renamed the property and will wait for responses from the material team:)

chunhtai · 2025-08-13T21:24:52Z

packages/flutter/lib/src/material/snack_bar.dart

@@ -289,6 +289,7 @@ class SnackBar extends StatefulWidget {
    this.showCloseIcon,
    this.closeIconColor,
    this.duration = _snackBarDisplayDuration,
+    this.persist = false,


What if developer wants it to not persist, but talkback is on? I think this may need to be nullable and if it is null, we can derive it from either action not null or accessibleNavigation is on. If it is set, we should respect it no matter what.

victorsanni · 2025-08-19T21:20:49Z

packages/flutter/lib/src/material/snack_bar.dart

@@ -459,6 +460,14 @@ class SnackBar extends StatefulWidget {
  ///  * <https://material.io/design/components/snackbars.html>
  final Duration duration;

+  /// Whether the snack bar will stay or auto-dismiss after timeout.
+  ///
+  /// If true, the snack bar is still there even after the timeout, until the


maybe remains displayed or remains visible? To be more descriptive.

chunhtai · 2025-08-19T21:27:00Z

packages/flutter/lib/src/material/snack_bar.dart

+  /// If true, the snack bar is still there even after the timeout, until the
+  /// user taps the action button or the close icon. If false, the snack bar
+  /// will be dismissed after the timeout. If this is null but the snackbar
+  /// action is not null, the snackbar will persist as well.


Since we are not relying on screen reader on/off. We can make this non-null and do something like

SnackBar( bool? persist ): this.persist = perisit ?? action != null;

this will mean snackbar with action never auto-dismisses. which is a breaking change. Is this intended?

yes, since this is the material guideline, we should make it the default and communicate to the developer.

I wasn't too sure before because I was waiting for material team's response, but now they do. so we should go with this breaking change

chunhtai · 2025-08-19T21:29:22Z

packages/flutter/lib/src/material/snack_bar.dart

+  ///
+  /// If true, the snack bar is still there even after the timeout, until the
+  /// user taps the action button or the close icon. If false, the snack bar
+  /// will be dismissed after the timeout. If this is null but the snackbar


Maybe

If not provided, this is set to true if [action] is not null

also consider separate each if sentence into a new paragraph for readability

QuncCccccc · 2025-08-19T23:24:40Z

Migration guide: flutter/website#12329

chunhtai

LGTM, just one minor comment

chunhtai · 2025-08-21T20:13:08Z

packages/flutter/lib/src/material/scaffold.dart

@@ -198,23 +198,12 @@ class ScaffoldMessengerState extends State<ScaffoldMessenger> with TickerProvide
      Queue<ScaffoldFeatureController<SnackBar, SnackBarClosedReason>>();
  AnimationController? _snackBarController;
  Timer? _snackBarTimer;
-  bool? _accessibleNavigation;
+  late bool? _accessibleNavigation;


why do we need late? or do you forgot to remove the nullable?

When I removed the block of code in didChangeDependencies, I got this lint rule to add late to _accessibleNavigation. Seems we still need it to control whether SnackBars have animation when it's sliding in and out.

Or change it to bool _accessibleNavigation = false;?

github-actions bot added framework flutter/packages/flutter repository. See also f: labels. f: material design flutter/packages/flutter/material repository. labels Jul 31, 2025

gemini-code-assist bot reviewed Jul 31, 2025

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QuncCccccc requested a review from chunhtai July 31, 2025 23:23

QuncCccccc marked this pull request as ready for review July 31, 2025 23:23

victorsanni reviewed Aug 1, 2025

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QuncCccccc force-pushed the make_snack_bar_dismissible branch from 883566c to f81edef Compare August 12, 2025 21:15

chunhtai reviewed Aug 13, 2025

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QuncCccccc force-pushed the make_snack_bar_dismissible branch from 9c7dbf7 to da486ab Compare August 14, 2025 23:48

QuncCccccc and others added 8 commits August 19, 2025 14:05

Add dismissible to SnackBar

ef753e9

Remove print

471e3f9

Update dismissible chceck

c542eb6

Remove empty line

e6fd23d

Rename dismissible to persist

5a45027

persist has higher priority than talkback setting

dec1090

Add tests

8c7f8f9

Snackbar will not dismiss as long as action is not null

6991c52

QuncCccccc force-pushed the make_snack_bar_dismissible branch from 973b93b to 6991c52 Compare August 19, 2025 21:05

Update api doc

04cb537

victorsanni reviewed Aug 19, 2025

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chunhtai reviewed Aug 19, 2025

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QuncCccccc mentioned this pull request Aug 19, 2025

Migration guide for SnackBar default behavior with action flutter/website#12329

Open

4 tasks

Fix failed tests

a6515de

github-actions bot added d: api docs Issues with https://api.flutter.dev/ d: examples Sample code and demos labels Aug 19, 2025

QuncCccccc added 2 commits August 19, 2025 16:18

Fix comments, remove unnecessary code, fix test

9a1f558

Update API doc based on feedback

6ddd962

QuncCccccc changed the title ~~Make SnackBar dismissible after timeout~~ SnackBar with action no longer auto-dismiss Aug 19, 2025

victorsanni approved these changes Aug 20, 2025

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Merge branch 'master' into make_snack_bar_dismissible

f1aead3

chunhtai approved these changes Aug 21, 2025

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SnackBar with action no longer auto-dismiss #173084

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SnackBar with action no longer auto-dismiss #173084

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QuncCccccc commented Jul 31, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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QuncCccccc commented Aug 19, 2025

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QuncCccccc Aug 21, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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QuncCccccc commented Jul 31, 2025 •

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QuncCccccc Aug 21, 2025 •

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