feat: added errorPadding property to `TextField` by abikko · Pull Request #177826 · flutter/flutter

abikko · 2025-10-31T05:41:14Z

This PR closes: #175834

Added errorPadding property,
Currently it's not ready yet.

If you had to change anything in the flutter/tests repo, include a link to the migration guide as per the breaking change policy.

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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.

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flutter-dashboard · 2025-10-31T05:41:16Z

It looks like this pull request may not have tests. Please make sure to add tests or get an explicit test exemption before merging.

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Code Review

This pull request introduces a new errorPadding property to InputDecoration and its related theme classes. This allows for specifying custom padding for the error text in text fields. The property has been plumbed through InputDecoration, InputDecorationTheme, and InputDecorationThemeData.

My review has identified a critical issue where the new errorPadding property is incorrectly wired to use the contentPadding value. I've also pointed out a couple of places where documentation for the new public properties is missing, which is a violation of the repository's style guide.

gemini-code-assist · 2025-10-31T05:43:56Z


    final _Decorator decorator = _Decorator(
      decoration: _Decoration(
+        errorPadding: decorationContentPadding,


The errorPadding is being incorrectly initialized with decorationContentPadding, which is derived from decoration.contentPadding. This is likely a copy-paste error. Since the errorPadding feature is not fully implemented yet (as per the TODOs), it would be safer to initialize this to null for now. When the feature is implemented, this should be changed to resolve decoration.errorPadding.

errorPadding: null,

gemini-code-assist · 2025-10-31T05:43:56Z

+  // TODO(abikko): add documentation after implementing error padding in text field
+  final EdgeInsetsGeometry? errorPadding;


This public property should have a documentation comment explaining its purpose.¹

/// Overrides the default value for [InputDecoration.errorPadding]. // TODO(abikko): add documentation after implementing error padding in text field final EdgeInsetsGeometry? errorPadding;

Style Guide References

Footnotes

All public members should have documentation. ↩

abikko · 2025-11-04T10:06:39Z

@tirth-patel-nc Hi!

Who will review this PR?

justinmc

Thanks for jumping on fixing this. I agree with the need for an errorPadding property like this, but I think the implementation should be in _layout (see my comment below).

justinmc · 2025-11-06T17:41:56Z

It's probably not strictly necessary to include an example for a straightforward change like this. However, if you want to include it as a dartpad example in the errorPadding docs to show people how to solve the problem from the issue, that's probably worth it.

If you do keep this example, you'll have to add a test for it too.

I think that in new release, I have to clearly explain how that ErrorPadding works! :)

Thanks for review, I appreciate that!

Tomorrow I will try to implement your suggestions, and write some tests and documentation

justinmc · 2025-11-06T17:42:29Z

  final Color fillColor;
  final Color hoverColor;
  final bool isHovering;
+  final EdgeInsetsGeometry? contentPadding;


Is this used anywhere?

I am assuming that we will use it _EditableText RenderBox, for calculating the padding in _Decorator

justinmc · 2025-11-06T17:43:28Z

  static BoxParentData _boxParentData(RenderBox box) => box.parentData! as BoxParentData;

-  EdgeInsetsDirectional get contentPadding => decoration.contentPadding;
+  EdgeInsetsDirectional get contentPadding => decoration.errorPadding ?? decoration.contentPadding;


Won't this also affect the position of the content?

There is a problem that _EditableText is "surrounded" by size of _Decorator which extends RenderBox

And we have to use errorPadding(assuming that contentPadding will be more than ErrorPadding)

justinmc · 2025-11-06T17:45:13Z

  /// and `EdgeInsets.fromLTRB(12, 24, 12, 16)` when [isDense] is false.
  final EdgeInsetsGeometry? contentPadding;

+  ///TODO(abikko): add documentation after implementing error padding in text field


Don't forget this. This is where I'd add your example.

justinmc · 2025-11-06T17:49:29Z

+        child: Padding(
+          padding: contentPadding,


I think you probably want to implement the padding in the layout method of InputDecorator, not here.

Yes, today I was thinking about moving from here to implementing it to layout for RenderBox InputDecorator

thanks!

@abikko Do you still intend to come back to this PR and move this to the _layout method instead of a Padding widget?

flutter-dashboard · 2025-12-09T19:25:56Z

This pull request executed golden file tests, but it has not been updated in a while (20+ days). Test results from Gold expire after as many days, so this pull request will need to be updated with a fresh commit in order to get results from Gold.

For more guidance, visit Writing a golden file test for package:flutter.

Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing.

danielkiing3 · 2026-01-18T17:58:48Z

I'm a bit concerned about the scope of this change

Exposing errorPadding addressed just one case, but the underlying issue cut across all other form of supporting text for FormField as whole

This same layout coupling has effect on "helper", "helperText" in Formfield's decoration

I've not really had time to look into the implementation details myself, but from a API design pov, this feels like a styling level fix for what is really a structual concern

I feel if there is a need for padding control for errors, i want to believe it's very likely needed consistently across other supporting widgets exposed by Formfield as well

Maybe elevating the padding control to FormField itself might be better in this case, or just exposing a unifield field like supportingPadding will be a better design?

justinmc

@danielkiing3 Thanks for chiming in here. When you say FormField I guess you mean TextFormField? I think you're right that any API we add here should probably affect both error and helper (which are positioned in the same place today).

justinmc · 2026-01-22T22:43:57Z

+        child: Padding(
+          padding: contentPadding,


@abikko Do you still intend to come back to this PR and move this to the _layout method instead of a Padding widget?

dkwingsmt · 2026-02-11T19:39:05Z

@abikko Thanks for your contribution! Since I haven't seen a reply, I'm going to reluctantly close this pull request for now, but if you get time to address the comments, we'd be more than happy to take a look at a new patch. If you do send a new patch, it would be very useful to reference this one in the description in order to help reviewers see the previous context.

feat: added errorPadding property

c784f0f

github-actions Bot added framework flutter/packages/flutter repository. See also f: labels. p: material_ui material_ui package in flutter/packages labels Oct 31, 2025

abikko mentioned this pull request Oct 31, 2025

Add Theme-level option to align error text with the text field border (remove default indent/padding) #175834

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gemini-code-assist Bot reviewed Oct 31, 2025

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chore: added assigning errorPadding property to input_decoration

20e03f9

github-actions Bot added a: text input Entering text in a text field or keyboard related problems d: api docs Issues with https://api.flutter.dev/ d: examples Sample code and demos labels Nov 4, 2025

feat: added padding only for text

94eeea9

dkwingsmt requested a review from justinmc November 5, 2025 19:19

justinmc reviewed Nov 6, 2025

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dkwingsmt changed the title ~~feat: added errorPadding property~~ feat: added errorPadding property to TextField Nov 19, 2025

dkwingsmt requested a review from justinmc November 19, 2025 19:21

loic-sharma requested a review from Renzo-Olivares December 11, 2025 21:23

Renzo-Olivares requested review from justinmc and removed request for justinmc January 15, 2026 22:00

loic-sharma self-requested a review January 22, 2026 19:29

justinmc reviewed Jan 22, 2026

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dkwingsmt closed this Feb 11, 2026

		// TODO(abikko): add documentation after implementing error padding in text field
		final EdgeInsetsGeometry? errorPadding;

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abikko commented Oct 31, 2025 •

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