CHANGE: Update asset Actions.inputactions to use UI Toolkit framework

[josepmariapujol-unity]

Description

This PR is updating the UI for asset Actions.inputactions to use UI Toolkit framework.

(Revert and Apply buttons still use IMGUI)

Testing status & QA

Manually test buttons and UI expecting same results than before.

Screen.Recording.2026-03-23.at.14.33.05.mov

Overall Product Risks

Please rate the potential complexity and halo effect from low to high for the reviewers. Note down potential risks to specific Editor branches if any.

• Complexity: 1
• Halo Effect: 1

Comments to reviewers

Please describe any additional information such as what to focus on, or historical info for the reviewers.

Checklist

Before review:

• Changelog entry added.
  • Explains the change in Changed, Fixed, Added sections.
  • For API change contains an example snippet and/or migration example.
  • JIRA ticket linked, example (case %%). If it is a private issue, just add the case ID without a link.
  • Jira port for the next release set as "Resolved".
• Tests added/changed, if applicable.
  • Functional tests Area_CanDoX, Area_CanDoX_EvenIfYIsTheCase, Area_WhenIDoX_AndYHappens_ThisIsTheResult.
  • Performance tests.
  • Integration tests.
• Docs for new/changed API's.
  • Xmldoc cross references are set correctly.
  • Added explanation how the API works.
  • Usage code examples added.
  • The manual is updated, if needed.

During merge:

• Commit message for squash-merge is prefixed with one of the list:
  • NEW: ___.
  • FIX: ___.
  • DOCS: ___.
  • CHANGE: ___.
  • RELEASE: 1.1.0-preview.3.

[u-pr]

The review identified a few areas for improvement, primarily concerning localization and editor state management. There is also a minor concern regarding UI implementation stability.

• State Management: Recommended calling serializedObject.Update() in CreateInspectorGUI to ensure data consistency.
• Localization: Migration to UIToolkit has replaced localized strings with hardcoded ones.
• UI Implementation: Noted a dependency on internal UIToolkit selectors which may be fragile.
• Validation: Confirmed correct usage of change event values in one instance.

_{🤖 Helpful? 👍/👎}

[codecov-github-com]

Codecov Report

Attention: Patch coverage is 0% with 131 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
.../Editor/AssetImporter/InputActionImporterEditor.cs	0.00%	131 Missing ⚠️

@@             Coverage Diff             @@
##           develop    #2394      +/-   ##
===========================================
- Coverage    77.90%   77.85%   -0.06%     
===========================================
  Files          476      482       +6     
  Lines        97613    97833     +220     
===========================================
+ Hits         76048    76163     +115     
- Misses       21565    21670     +105     

Flag	Coverage Δ
inputsystem_MacOS_2022.3	5.29% <0.00%> (-0.24%)	⬇️
inputsystem_MacOS_2022.3_project	75.28% <0.00%> (-0.12%)	⬇️
inputsystem_MacOS_6000.0	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_MacOS_6000.0_project	77.18% <0.00%> (-0.11%)	⬇️
inputsystem_MacOS_6000.3	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_MacOS_6000.3_project	77.19% <0.00%> (-0.11%)	⬇️
inputsystem_MacOS_6000.4	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_MacOS_6000.4_project	77.19% <0.00%> (-0.11%)	⬇️
inputsystem_MacOS_6000.5	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_MacOS_6000.5_project	77.19% <0.00%> (-0.12%)	⬇️
inputsystem_MacOS_6000.6	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_MacOS_6000.6_project	77.19% <0.00%> (-0.12%)	⬇️
inputsystem_Ubuntu_2022.3_project	75.08% <0.00%> (-0.12%)	⬇️
inputsystem_Ubuntu_6000.0	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Ubuntu_6000.0_project	76.99% <0.00%> (-0.11%)	⬇️
inputsystem_Ubuntu_6000.3	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Ubuntu_6000.3_project	76.98% <0.00%> (-0.12%)	⬇️
inputsystem_Ubuntu_6000.4	5.28% <0.00%> (-0.04%)	⬇️
inputsystem_Ubuntu_6000.4_project	77.00% <0.00%> (-0.11%)	⬇️
inputsystem_Ubuntu_6000.5	5.28% <0.00%> (-0.04%)	⬇️
inputsystem_Ubuntu_6000.5_project	76.99% <0.00%> (-0.12%)	⬇️
inputsystem_Ubuntu_6000.6	5.28% <0.00%> (-0.04%)	⬇️
inputsystem_Ubuntu_6000.6_project	76.99% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_2022.3	5.29% <0.00%> (-0.24%)	⬇️
inputsystem_Windows_2022.3_project	75.41% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_6000.0	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Windows_6000.0_project	77.31% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_6000.3	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Windows_6000.3_project	77.31% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_6000.4	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Windows_6000.4_project	77.31% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_6000.5	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Windows_6000.5_project	77.31% <0.00%> (-0.12%)	⬇️
inputsystem_Windows_6000.6	5.27% <0.00%> (-0.04%)	⬇️
inputsystem_Windows_6000.6_project	77.31% <0.00%> (-0.12%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
.../Editor/AssetImporter/InputActionImporterEditor.cs	0.00% <0.00%> (ø)

... and 8 files with indirect coverage changes

ℹ️ Need help interpreting these results?

[Pauliusd01]

/test_plan

[u-pr]

Test Plan

• Test plan approved by PR author
• Test execution in progress
• Test execution complete
• Ready for merge

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Summary of Changes & Risk Assessment

Summary of Changes

This PR migrates the InputActionImporterEditor (the inspector for .inputactions assets) from IMGUI to UI Toolkit. It replicates the existing functionality, including the "Edit Asset" button, project-wide action assignment, and C# code generation settings, while maintaining the standard Apply/Revert buttons via an IMGUIContainer.

Risk Assessment

• High Risk Areas: None identified.
• Medium Risk Areas: C# code generation path selection and validation logic, Project-wide action assignment state management.
• Low Risk Areas: Visual styling of help boxes and buttons, placeholder text behavior in TextFields.

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Test Scenarios

Functional Testing

• Edit Button Logic: Verify that the "Edit Asset" button correctly opens the Input Actions editor window, or redirects to Project Settings if the asset is assigned as the project-wide actions asset (referencing InputActionImporterEditor.cs:L254).
• Project-wide Assignment: In a project with no actions assigned, select an asset and click "Assign as the Project-wide Input Actions". Verify the UI updates to show the "Project-wide" info box and the button disappears.
• C# Code Generation Toggle: Toggle "Generate C# Class" and verify that the path, class name, and namespace fields appear/disappear accordingly (referencing InputActionImporterEditor.cs:L191).
• File Browser: Click the ... button next to "C# Class File". Select a location and verify the path is correctly updated in the text field and applied to the serializedObject.
• Validation UI: Enter an invalid C# identifier (e.g., starting with a number) in the "C# Class Name" field. Verify the "Must be a valid C# identifier" error HelpBox appears immediately.

Regression Testing

• Apply/Revert Workflow: Modify a field (e.g., change the class name), verify the standard Apply and Revert buttons become active, and ensure clicking Apply saves the changes to the asset's meta file.
• Selection Persistence: Change selection between different .inputactions assets and ensure the inspector UI correctly updates to reflect the properties of the currently selected asset.
• Play Mode Safety: Verify that the "Assign as Project-wide Input Actions" button is disabled when the Editor is in Play Mode (referencing InputActionImporterEditor.cs:L94).

Edge Cases

• Placeholder Behavior: Verify that the custom placeholders for "C# Class File", "C# Class Name", and "C# Class Namespace" disappear when the field is focused or contains text, and reappear when empty and unfocused (referencing SetupPlaceholder at InputActionImporterEditor.cs:L201).
• External Path: Try to save the C# wrapper file outside the Assets/ folder using the browse button; verify the path handling logic correctly handles or restricts the path.

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_{💡 This test plan updates automatically when /test_plan is run on new commits. If you have any feedback, please reach out in #ai-qa}

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🤖 Helpful? Please react with 👍/👎 | Questions❓Please reach out in Slack #ask-u-pr

[Pauliusd01]

24.03.2026.-.Unity.457.mp4

The IMGUI version seems to have handled scaling better for the button text

[Pauliusd01]

The text in the old version also looked a bit better, It's almost like the UIToolkit version lacks anti aliasing. A UIToolkit issue or maybe something you forgot to set? Either way I'd be fine with ignoring it, just mentioning. It is more noticeable in real life than this screenshot

[Pauliusd01]

LGTM, left only some minor comments about issues with scaling and a nitpick about the text looking slightly different. I think only the scaling issue should be looked at seriously