[transitrix]

Summary

Implements automatic detection and CSS generation for wide views, applying landscape page layout without manual CSS class assignment.

What's new

Wide view detection in CSS generation:

• Extends generatePagedMediaCss(metadata) to accept view specifications with width/height dimensions
• Detects views where width > height and automatically applies page: landscape CSS rule
• Sanitizes view IDs for safe CSS identifier generation

Landscape page handling:

• A4 landscape page size correctly declared (842 × 595 pt)
• Running footer adjusts to landscape page width (15mm margins)
• Page-break-inside avoid ensures diagrams stay intact

Tests:

• 47 test cases covering wide/portrait view detection, edge cases, special characters
• All tests passing

Architecture

Wide view detection happens at CSS generation time:

1. Caller provides view specifications with width/height to generatePagedMediaCss()
2. Module detects wide views (width > height) and generates CSS selectors
3. HTML elements with matching id automatically render on landscape pages
4. No manual class assignment needed; detection is automatic

Integration example

const metadata = {
  issuer: 'Acme Corp',
  document_identity: 'PRODUCT-MRD-1.0',
  views: [
    { id: 'diagram-arch', width: 1200, height: 600 }, // wide → landscape
    { id: 'diagram-flow', width: 400, height: 800 },  // portrait → portrait
  ],
};
const html = wrapHtmlForPrintRendering(content, metadata);
// diagram-arch renders on landscape page; diagram-flow on portrait page

Acceptance criteria met

✓ Wide views automatically use landscape pages
✓ Portrait views stay portrait
✓ Page size correctly declared (landscape A4: 842 × 595 pt)
✓ Layout is stable across renders

Part of larger work

This implements automatic landscape page detection for wide diagram views:

• Engine selection and paged-media CSS specification (merged)
• Running footer paged-media CSS (merged)
• Wide view detection for landscape pages (this PR)

Testing

cd packages/document-renderer
node tests/test_paged_media_css.mjs