Feature/improve custom rotate

[quhxl]

Description

This PR improves the usability of the "Rotate by Custom Degrees" tool by addressing two limitations:

• Larger previews: Increased thumbnail height (h-36 to h-64) and reduced grid density to improve visual feedback when adjusting small rotation angles.
• Floating-point support: Replaced parseInt with parseFloat, added step="0.1" to inputs, and implemented rounding to 1 decimal place for more precise control.

Fixes #630

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

🧪 How Has This Been Tested?

Please describe how you tested your changes so that maintainers can verify them. Include enough detail for someone else to reproduce your tests.

Checklist:

• Verified output manually
• Tested with relevant sample documents or data
• Wrote Vite Test Case (if applicable)

Test details:

• Uploaded scanned PDFs with slight skew (~0.5°–2°)
• Applied fractional rotations (e.g. 1.2, -0.8)

Checklist:

• I have signed the Contributor License Agreement (CLA) or my organization has signed the Corporate CLA
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Summary by CodeRabbit

• UI/UX Changes
  • Increased per-page thumbnail height for improved visibility.
  • Adjusted thumbnail grid to show fewer columns on smaller screens and increased spacing between items.
• New Features
  • Rotation controls now accept and apply decimal angles, with 0.1° step precision and values normalized to one decimal place.

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e95b70ab-1c4f-4a43-a2cf-272963614761

📥 Commits

Reviewing files that changed from the base of the PR and between ec178bd and 0ed5e95.

📒 Files selected for processing (1)

• src/js/logic/rotate-custom-page.ts

🚧 Files skipped from review as they are similar to previous changes (1)

• src/js/logic/rotate-custom-page.ts

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📝 Walkthrough

Walkthrough

Increased thumbnail preview size and adjusted grid layout; enabled floating-point rotation inputs with 0.1-degree steps and one-decimal rounding for both per-page and batch rotation controls.

Changes

Cohort / File(s)	Summary
Thumbnail Preview Size src/pages/rotate-custom.html, src/js/logic/rotate-custom-page.ts	Increased thumbnail container height (h-36 → h-64) and changed grid columns/gap (grid-cols-2 sm:grid-cols-3 md:grid-cols-4 lg:grid-cols-5 gap-4 → grid-cols-1 sm:grid-cols-2 md:grid-cols-2 lg:grid-cols-3 gap-6).
Floating-Point Angle Support src/js/logic/rotate-custom-page.ts, src/pages/rotate-custom.html	Replaced integer parsing (parseInt) with decimal parsing (parseFloat), set numeric inputs step="0.1", implemented rounding to one decimal place on increment/decrement/apply flows, and normalized input values and pageState.rotations to one-decimal precision.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Poem

🐰 I hopped in to tweak the view,
Thumbnails taller, crisp and true.
Angles now a silky glide,
0.1 steps, one-decimal pride.
Nibbles of precision — joy anew! ✨

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Title check	❓ Inconclusive	The title is vague and overly broad, using generic language like 'improve' without clearly specifying what is being improved about the custom rotate feature.	Consider a more specific title such as 'Add floating-point support and larger previews to custom rotate tool' to better convey the main improvements.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description check	✅ Passed	The PR description comprehensively covers the changes, issue reference, type of change, and testing performed, matching the template structure and requirements.
Linked Issues check	✅ Passed	The PR successfully addresses both objectives from issue #630: floating-point input support (parseFloat, step=0.1, rounding to 1 decimal) and larger previews (h-64, reduced grid density).
Out of Scope Changes check	✅ Passed	All changes directly align with the two objectives in issue #630: thumbnail sizing, grid layout adjustments, and floating-point input support are all in scope.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[quhxl]

I have read the CLA Document and I hereby sign the CLA

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/js/logic/rotate-custom-page.ts`:
- Around line 152-153: The parseFloat usage in the apply handlers (e.g., where
you read input.value and set pageState.rotations[pageIndex]) accepts
NaN/Infinity and un-normalized numbers; fix by validating the parsed value with
Number.isFinite and normalizing to one decimal place before assignment (e.g.,
parse -> Number.isFinite check -> round to one decimal such as Math.round(value
* 10) / 10) and fallback to 0 when invalid; apply the same change to both the
handler that sets pageState.rotations[pageIndex] and the other apply path around
the code referenced near line 393 so all typed angles enforce finite values and
one-decimal precision.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a57585cb-7a59-42ec-9602-678c7aec094f

📥 Commits

Reviewing files that changed from the base of the PR and between ed6e6c0 and 7f9c352.

📒 Files selected for processing (3)

• docs/tools/rotate-custom.md
• src/js/logic/rotate-custom-page.ts
• src/pages/rotate-custom.html