Add alwaysSizeToContent argument to Overlay. by knopp · Pull Request #182009 · flutter/flutter

knopp · 2026-02-06T16:10:46Z

Fixes #182008.

This PR introduces alwaysSizeToContent argument to Overlay. When set to true, this ensures the Overlay
is always sized to content, even if the constraints are finite.

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.

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.

gemini-code-assist

Code Review

This pull request introduces an alwaysSizeToContent argument to the Overlay widget. When this is set to true, the overlay will size itself to its content even when given finite constraints, which is useful for scenarios where an overlay should wrap its content. The implementation correctly propagates this new property down to the render object and adds a new, specific error message for when alwaysSizeToContent is true but no suitable child is available to determine the size. The changes are accompanied by relevant tests. My feedback includes a minor documentation typo fix and a suggestion to make the new error message more actionable for developers.

gemini-code-assist · 2026-02-06T16:20:36Z

+        ErrorDescription(
+          'When created with alwaysSizeToContent=true the Overlay requires at least one '
+          'non-positioned OverlayEntry with canSizeOverlay set to true',
+        ),
+        ErrorHint(
+          'Try removing alwaysSizeToContent=true or provide a suitable child that can size the Overlay',
+        ),


The error description and hint could be more precise and actionable to better guide the developer, in line with the style guide's principle of providing useful error messages.

ErrorDescription( 'When `alwaysSizeToContent` is true, the Overlay requires at least one ' 'non-positioned `OverlayEntry` with `canSizeOverlay` set to true to determine its size.', ), ErrorHint( 'Try removing `alwaysSizeToContent: true`, or add an `OverlayEntry` with `canSizeOverlay: true` that is not a `Positioned` widget.', ),

References

Error messages should be useful. This change makes the error message more actionable and easier to understand for developers. ^(link)

chunhtai · 2026-02-06T16:58:25Z

+  ///
+  /// Normally overlay will only size itself to content if the the incoming
+  /// constraints are infinite and there is a [OverlayEntry] that can size
+  /// the overlay. Setting this to `true` will force this behavior even for


also mention [OverlayEntry.canSizeOverlay] set to true

chunhtai · 2026-02-06T17:00:16Z

+  ///
+  /// Setting this to true requires an [OverlayEntry] that can size the overlay
+  /// based on itself.
+  final bool alwaysSizeToContent;


does it worth to make this a tri state? either enum or bool?, where always size by content, always not size by content, and size depends on infinite constraint

Not sure, if there is consensus tri-state would be better I'll can rework this.

thinking a bit more, I think this is fine for now.

chunhtai · 2026-02-06T17:06:35Z

+  /// the overlay. Setting this to `true` will force this behavior even for
+  /// finite (but possibly loose) constraints.
+  ///
+  /// Setting this to true requires an [OverlayEntry] that can size the overlay


should also mention it throws when there isn't a overlay entry that can size the overlay

chunhtai

besides the doc related comments, otherwise LGTM

chunhtai · 2026-02-20T23:41:00Z

+  ///
+  /// Setting this to true requires an [OverlayEntry] that can size the overlay
+  /// based on itself.
+  final bool alwaysSizeToContent;


thinking a bit more, I think this is fine for now.

Piinks · 2026-03-17T23:14:26Z

Greetings from triage! Is this a change we want to move forward with?

…er#182009)

Fixes flutter#182008. This PR introduces `alwaysSizeToContent` argument to `Overlay`. When set to true, this ensures the Overlay is always sized to content, even if the constraints are finite. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. 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](https://developers.google.com/gemini-code-assist/docs/review-github-code). 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.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

…er#182009)

Roll Flutter from fb03253e32ce to 3d69471c0bf9 (69 revisions) flutter/flutter@fb03253...3d69471 2026-04-01 engine-flutter-autoroll@skia.org Roll Dart SDK from 1308a3076402 to 043a2bfd56ff (1 revision) (flutter/flutter#184453) 2026-04-01 engine-flutter-autoroll@skia.org Roll Skia from a657b5446209 to c2363c39c283 (2 revisions) (flutter/flutter#184448) 2026-04-01 104349824+huycozy@users.noreply.github.com Fix layout overflowed in small screen in SensitiveContent's example (flutter/flutter#184179) 2026-04-01 engine-flutter-autoroll@skia.org Roll Skia from e0b25041a5d5 to a657b5446209 (1 revision) (flutter/flutter#184445) 2026-04-01 engine-flutter-autoroll@skia.org Roll Dart SDK from 75a089eb6bf9 to 1308a3076402 (3 revisions) (flutter/flutter#184444) 2026-04-01 jesswon@google.com [AGP 9] Bumping KGP error minimum to 2.0.0 (flutter/flutter#184385) 2026-04-01 bkonyi@google.com [ Tool ] Migrate `flutter analyze` to use LSP (flutter/flutter#183785) 2026-04-01 30870216+gaaclarke@users.noreply.github.com Adds uber sdf shader gradients with blend (flutter/flutter#184090) 2026-04-01 sys.int64@gmail.com Add bottom safe area padding to licenses package license page (flutter/flutter#182425) 2026-04-01 ahmedsameha1@gmail.com Handle#6537 third grouped tests (flutter/flutter#183059) 2026-04-01 engine-flutter-autoroll@skia.org Roll Skia from f37239a7a689 to e0b25041a5d5 (9 revisions) (flutter/flutter#184436) 2026-03-31 jason-simmons@users.noreply.github.com [Impeller] Do not log an error when wrapping an empty texture as a TextureGLES (flutter/flutter#184377) 2026-03-31 jason-simmons@users.noreply.github.com Remove the default_git_folder GN argument (flutter/flutter#184152) 2026-03-31 jason-simmons@users.noreply.github.com Remove the cupertino_icons dependency from the spell_check integration test (flutter/flutter#184398) 2026-03-31 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from pM94cWC9cSgao0CG0... to fV-JIWUt4FQGeDtEe... (flutter/flutter#184383) 2026-03-31 engine-flutter-autoroll@skia.org Roll Dart SDK from eaeccf98848d to 75a089eb6bf9 (1 revision) (flutter/flutter#184379) 2026-03-31 mdebbar@google.com [web] Fix autofill in iOS 26 Safari (flutter/flutter#182024) 2026-03-31 engine-flutter-autoroll@skia.org Roll Fuchsia GN SDK from SEfYx3xgueX3aFAY3... to JLBh4Z9PKsjIJcqDU... (flutter/flutter#184368) 2026-03-31 loic.peron@inetum.com [Windows] Restore and enable IAccessibleEx implementation (flutter/flutter#175406) 2026-03-31 30870216+gaaclarke@users.noreply.github.com Revert "Even more awaits (#184042)" (flutter/flutter#184429) 2026-03-31 engine-flutter-autoroll@skia.org Roll Skia from dfd8f8002800 to f37239a7a689 (2 revisions) (flutter/flutter#184374) 2026-03-31 jacksongardner@google.com Remove workaround for fake impeller images in iOS simulator. (flutter/flutter#184264) 2026-03-31 victorsanniay@gmail.com Even more awaits (flutter/flutter#184042) 2026-03-31 engine-flutter-autoroll@skia.org Roll Packages from 582f0e7 to b04f3e5 (6 revisions) (flutter/flutter#184393) 2026-03-30 30870216+gaaclarke@users.noreply.github.com Fixes a flake in reload shaders tests (flutter/flutter#184268) 2026-03-30 jason-simmons@users.noreply.github.com Remove an obsolete script for setting up remote GDB sessions on Android devices (flutter/flutter#184357) 2026-03-30 engine-flutter-autoroll@skia.org Roll Skia from 8dcde79fef2a to dfd8f8002800 (10 revisions) (flutter/flutter#184363) 2026-03-30 engine-flutter-autoroll@skia.org Roll Dart SDK from 0aaccc3c8004 to eaeccf98848d (2 revisions) (flutter/flutter#184362) 2026-03-30 bkonyi@google.com [ Tool ] Remove `flutter running-apps` command (flutter/flutter#183742) 2026-03-30 137456488+flutter-pub-roller-bot@users.noreply.github.com Roll pub packages (flutter/flutter#184045) 2026-03-30 jmccandless@google.com Rick roll triagers on/near April 1st (flutter/flutter#184355) 2026-03-30 49699333+dependabot[bot]@users.noreply.github.com Bump codecov/codecov-action from 5.5.0 to 6.0.0 in the all-github-actions group (flutter/flutter#184364) 2026-03-30 1961493+harryterkelsen@users.noreply.github.com fix(web): call ui.Picture.onDispose for the original picture only (flutter/flutter#184348) 2026-03-30 engine-flutter-autoroll@skia.org Roll Skia from e001e6901e3b to 8dcde79fef2a (7 revisions) (flutter/flutter#184356) 2026-03-30 jason-simmons@users.noreply.github.com [web] Make it safe to call dispose multiple times on a CkSurface (flutter/flutter#184270) 2026-03-30 jason-simmons@users.noreply.github.com Roll HarfBuzz to 13.2.1 (flutter/flutter#184210) 2026-03-30 srawlins@google.com web_ui: Remove unused parameters in a few places (flutter/flutter#183156) 2026-03-30 saurabhmirajkar000@gmail.com Update TabBar documentation to clarify indicatorWeight behavior (flutter/flutter#184104) 2026-03-30 36861262+QuncCccccc@users.noreply.github.com Add title evaluation (flutter/flutter#184084) 2026-03-30 47866232+chunhtai@users.noreply.github.com fixes crash when invisible semantics nodes dropped from semantics tree (flutter/flutter#184226) 2026-03-30 engine-flutter-autoroll@skia.org Roll Skia from cdaae3e3fdef to e001e6901e3b (4 revisions) (flutter/flutter#184345) 2026-03-30 engine-flutter-autoroll@skia.org Roll Packages from 7ae082a to 582f0e7 (8 revisions) (flutter/flutter#184341) 2026-03-30 matej.knopp@gmail.com Add alwaysSizeToContent argument to Overlay. (flutter/flutter#182009) 2026-03-30 engine-flutter-autoroll@skia.org Roll Dart SDK from 598088a8a67f to 0aaccc3c8004 (1 revision) (flutter/flutter#184331) 2026-03-30 engine-flutter-autoroll@skia.org Roll Skia from 6d7ade938643 to cdaae3e3fdef (2 revisions) (flutter/flutter#184329) 2026-03-30 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from EnoD6zNQebz4EYuLk... to pM94cWC9cSgao0CG0... (flutter/flutter#184323) ...

Fixes flutter#182008. This PR introduces `alwaysSizeToContent` argument to `Overlay`. When set to true, this ensures the Overlay is always sized to content, even if the constraints are finite. ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. 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](https://developers.google.com/gemini-code-assist/docs/review-github-code). 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.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

github-actions Bot added the framework flutter/packages/flutter repository. See also f: labels. label Feb 6, 2026

knopp mentioned this pull request Feb 6, 2026

Fix overlay in size to content scenario with loose constraints #181490

Closed

9 tasks

gemini-code-assist Bot reviewed Feb 6, 2026

View reviewed changes

chunhtai reviewed Feb 6, 2026

View reviewed changes

justinmc self-requested a review February 10, 2026 23:14

knopp force-pushed the overlay_always_size_to_content branch from 74cc34f to f83dee7 Compare February 11, 2026 16:07

chunhtai self-requested a review February 11, 2026 16:29

chunhtai reviewed Feb 20, 2026

View reviewed changes

mattkae approved these changes Mar 30, 2026

View reviewed changes

knopp added 2 commits March 30, 2026 17:25

Add alwaysSizeToContent argument to Overlay.

8e80f6e

nits

65cb9e2

knopp force-pushed the overlay_always_size_to_content branch from f83dee7 to 65cb9e2 Compare March 30, 2026 15:25

knopp enabled auto-merge March 30, 2026 15:25

knopp added the CICD Run CI/CD label Mar 30, 2026

knopp added this pull request to the merge queue Mar 30, 2026

Merged via the queue into flutter:master with commit 939c21c Mar 30, 2026
76 of 77 checks passed

knopp deleted the overlay_always_size_to_content branch March 30, 2026 16:42

engine-flutter-autoroll mentioned this pull request Mar 30, 2026

Roll Flutter from fb03253e32ce to 939c21c5d02c (27 revisions) flutter/packages#11393

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 30, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

cd07363

…er#182009)

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 30, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

cb11e5f

…er#182009)

This was referenced Mar 30, 2026

Roll Flutter from fb03253e32ce to a64711534627 (28 revisions) flutter/packages#11394

Closed

Roll Flutter from fb03253e32ce to 3918685b84d2 (29 revisions) flutter/packages#11395

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 30, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

669a49d

…er#182009)

engine-flutter-autoroll mentioned this pull request Mar 30, 2026

Roll Flutter from fb03253e32ce to 6f07097c2496 (30 revisions) flutter/packages#11396

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 30, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

9cbfcb4

…er#182009)

engine-flutter-autoroll mentioned this pull request Mar 31, 2026

Roll Flutter from fb03253e32ce to aaa24c388b43 (45 revisions) flutter/packages#11402

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 31, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

b93e5a4

…er#182009)

engine-flutter-autoroll mentioned this pull request Mar 31, 2026

Roll Flutter from fb03253e32ce to aaa24c388b43 (45 revisions) flutter/packages#11404

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 31, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

0fed24b

…er#182009)

engine-flutter-autoroll mentioned this pull request Mar 31, 2026

Roll Flutter from fb03253e32ce to 5988a54381ed (48 revisions) flutter/packages#11406

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Mar 31, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

11dbc08

…er#182009)

engine-flutter-autoroll mentioned this pull request Apr 1, 2026

Roll Flutter from fb03253e32ce to 3d69471c0bf9 (69 revisions) flutter/packages#11408

Merged

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Apr 1, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

4c55518

…er#182009)

engine-flutter-autoroll mentioned this pull request Apr 1, 2026

Roll Flutter from fb03253e32ce to 984d612baac2 (70 revisions) flutter/packages#11409

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Apr 1, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

4b08ac8

…er#182009)

engine-flutter-autoroll mentioned this pull request Apr 1, 2026

Roll Flutter from fb03253e32ce to 22bc19ec8c34 (71 revisions) flutter/packages#11411

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Apr 1, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

cefb5f7

…er#182009)

engine-flutter-autoroll mentioned this pull request Apr 1, 2026

Roll Flutter from fb03253e32ce to 1460ed7e2630 (72 revisions) flutter/packages#11412

Closed

engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Apr 1, 2026

939c21c5d Add alwaysSizeToContent argument to Overlay. (flutter/flutt…

dba6bfd

…er#182009)

Piinks mentioned this pull request Apr 3, 2026

Flutter Notable Commits - 2026 #181433

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add alwaysSizeToContent argument to Overlay.#182009

Add alwaysSizeToContent argument to Overlay.#182009
knopp merged 2 commits into
flutter:masterfrom
knopp:overlay_always_size_to_content

knopp commented Feb 6, 2026

Uh oh!

gemini-code-assist Bot left a comment

Uh oh!

Uh oh!

gemini-code-assist Bot Feb 6, 2026

Uh oh!

chunhtai Feb 6, 2026

Uh oh!

chunhtai Feb 6, 2026

Uh oh!

knopp Feb 11, 2026

Uh oh!

chunhtai Feb 20, 2026

Uh oh!

chunhtai Feb 6, 2026

Uh oh!

chunhtai left a comment •

edited

Loading

Uh oh!

chunhtai Feb 20, 2026

Uh oh!

Piinks commented Mar 17, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Conversation

knopp commented Feb 6, 2026

Pre-launch Checklist

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

Uh oh!

gemini-code-assist Bot Feb 6, 2026

Choose a reason for hiding this comment

Uh oh!

chunhtai Feb 6, 2026

Choose a reason for hiding this comment

Uh oh!

chunhtai Feb 6, 2026

Choose a reason for hiding this comment

Uh oh!

knopp Feb 11, 2026

Choose a reason for hiding this comment

Uh oh!

chunhtai Feb 20, 2026

Choose a reason for hiding this comment

Uh oh!

chunhtai Feb 6, 2026

Choose a reason for hiding this comment

Uh oh!

chunhtai left a comment • 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!

chunhtai Feb 20, 2026

Choose a reason for hiding this comment

Uh oh!

Piinks commented Mar 17, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

chunhtai left a comment •

edited

Loading