Expose BorderRadius (LTRB) Information in Inspector for RenderDecoratedBox

[alpinnz]

PR Description

Overview

This PR adds support for exposing BorderRadius information in the Inspector when inspecting widgets that visually render rounded corners via BoxDecoration.

Previously, the Inspector displayed layout-related properties (size, padding), but did not expose borderRadius data, even when the widget clearly rendered rounded corners.

This improvement enhances Inspector’s usefulness for:

• UI/UX audits
• Design token verification
• Visual consistency validation
• Design system inspection workflows

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What This PR Adds

BorderRadius Extraction (BoxDecoration)

When inspecting a RenderDecoratedBox whose decoration is a BoxDecoration and contains a non-null borderRadius, the Inspector now displays:

Border Radius (LTRB): tl, tr, br, bl

Example

For:

Container(
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(8),
  ),
)

Inspector now shows:

Border Radius (LTRB): 8.0, 8.0, 8.0, 8.0

For asymmetric radius:

BorderRadius.only(
  topLeft: Radius.circular(8),
  topRight: Radius.circular(12),
)

Inspector shows:

Border Radius (LTRB): 8.0, 12.0, 0.0, 0.0

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Implementation Details

• Border radius is extracted only from RenderDecoratedBox

• Decoration must be of type BoxDecoration

• Defensive checks ensure:

  • decoration is BoxDecoration
  • borderRadius != null

• BorderRadiusGeometry is resolved using:

  borderRadius.resolve(TextDirection.ltr)

• Values are formatted explicitly as:

  topLeft, topRight, bottomRight, bottomLeft
  

• .toString() is not used

• No changes to rendering or layout behavior

• No new dependencies introduced

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Behavior Changes

Before

Inspector displayed:

• Size
• Padding

But did not show:

• Border radius

After

Inspector additionally displays:

• Border Radius (LTRB) when available

No existing behavior was removed or modified.

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Scope & Limitations

This PR focuses only on:

• BoxDecoration.borderRadius

It does not yet include:

• ClipRRect
• ShapeBorder
• Material.shape
• Circle shape extraction

Those may be addressed in a future enhancement if approved.

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Backward Compatibility

• No breaking changes
• No API changes
• UI layout remains intact
• Feature is additive only

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Environment Tested

• Flutter: 3.38.9
• Platform: Web
• Inspector version: 3.1.0

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Related Issue

Uploading 374311144a1f.mp4…

Closes #21