red/.planning/phases/05-pdf-fill-and-field-mapping/05-02-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech_stack, key_files, decisions, metrics

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
05-pdf-fill-and-field-mapping	02	frontend/documents	dnd-kit pdf-fields field-placer coordinate-conversion drag-and-drop	requires provides affects 05-01 field-placement-ui signature-field-overlay documents-detail-page pdf-viewer	added patterns @dnd-kit/core@^6.3.1 @dnd-kit/utilities@^3.2.2 dnd-kit-drag-overlay y-flip-coordinate-conversion droppable-pdf-zone	created modified teressa-copeland-homes/src/app/portal/(protected)/documents/[docId]/_components/FieldPlacer.tsx teressa-copeland-homes/src/app/portal/(protected)/documents/[docId]/_components/PdfViewer.tsx	DragOverlay used for ghost rendering during drag — avoids transform-based dragging which breaks coordinate math relative to the droppable container containerRef.getBoundingClientRect() called at drop time (not stale pageInfo.width) — captures current rendered size after zoom changes activatorEvent + delta pattern for final drop coordinates — activatorEvent gives the client position where drag started, delta gives displacement DroppableZone assigns both setNodeRef (dnd-kit) and containerRef (coordinate math) to same DOM node via combined ref callback top: top - heightPx applied to overlay divs — pdfToScreenCoords returns y of bottom-left corner, must shift up by field height for DOM top-left origin	duration completed_date tasks_completed files_created files_modified 1 min 2026-03-20 2 1 1

Phase 5 Plan 02: Drag-and-Drop Signature Field Placer Summary

One-liner: dnd-kit DndContext with draggable palette token + droppable PDF zone; Y-flip coordinate conversion persists fields to DB via PUT /api/documents/[id]/fields.

What Was Built

A complete drag-and-drop field placement system integrated into the document detail page:

1. FieldPlacer.tsx (321 lines) — New client component providing:

   • A DndContext wrapping both palette and PDF canvas
   • DraggableToken sub-component using useDraggable for the "Signature Field" palette item
   • DroppableZone sub-component using useDroppable to make the PDF canvas a valid drop target
   • DragOverlay showing a blue ghost rectangle during drag
   • screenToPdfCoords() — Y-flip formula converting DOM coordinates to PDF user space
   • pdfToScreenCoords() — inverse formula for rendering stored fields as overlays
   • Server sync: GET on mount (load existing), PUT on every add/remove (persist)
   • Per-page filtering (field.page === currentPage) so page 1 fields don't show on page 2

2. PdfViewer.tsx (updated) — Extended with:

   • pageInfo state (PageInfo | null) populated via onLoadSuccess callback
   • Math.max(page.view[0], page.view[2]) / Math.max(page.view[1], page.view[3]) for robust originalWidth/originalHeight (handles non-standard mediaBox ordering)
   • FieldPlacer wraps the Document/Page tree, receiving docId, pageInfo, currentPage
   • Only scale prop used on <Page> (not both width + scale)

Verification Results

• npm run build — compiled successfully (both tasks)
• FieldPlacer.tsx: 321 lines (minimum 80 required)
• @dnd-kit/core and @dnd-kit/utilities present in package.json
• PdfViewerWrapper.tsx unchanged (dynamic import wrapper still passes docId through)

Coordinate Conversion Details

The Y-flip formula is critical for correct field placement:

• DOM: Y=0 at top, increases downward
• PDF user space: Y=0 at bottom, increases upward
• pdfY = ((renderedH - screenY) / renderedH) * originalHeight
• This means dragging to the visual top of a page stores a high pdfY value (near originalHeight)
• containerRect.width/height used at drop time (not stale pageInfo) to handle zoom changes correctly

Commits

Task	Commit	Description
Task 1	6069ae5	feat(05-02): install dnd-kit and create FieldPlacer component
Task 2	7a36736	feat(05-02): extend PdfViewer with pageInfo state and FieldPlacer integration

Deviations from Plan

None — plan executed exactly as written.

The DroppableZone component uses a combined ref callback to assign both the dnd-kit setNodeRef and the containerRef simultaneously to the same DOM node — this was a minor implementation detail not explicitly specified in the plan but required for correct operation.

Self-Check: PASSED

• FOUND: FieldPlacer.tsx (321 lines)
• FOUND: PdfViewer.tsx (updated)
• FOUND commit: 6069ae5
• FOUND commit: 7a36736
• @dnd-kit/core and @dnd-kit/utilities in package.json
• Build: compiled successfully