Slice 4: Drag-and-Drop Input

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Parent

• PRD: NihongOCR MVP #1 (PRD: NihongOCR MVP)

What to build

Add drag-and-drop as a secondary input method. The Reading window (or a designated drop zone) accepts image file drops, which are fed through the same Capture Service and OCR pipeline as region captures. The resulting Reading is displayed in the same window.

This slice reuses all existing infrastructure and only adds the drop target handling.

Acceptance criteria

• Reading window accepts drag-and-drop of image files
• Dropped images are processed through the same pipeline as region captures
• Resulting Reading displays in the same window (replacing any current Reading)
• Temp file cleanup works for dropped files as well

Blocked by

• Slice 3: Real OCR Pipeline (Horizontal Text) #4 (Slice 3: Real OCR Pipeline (Horizontal Text))

Testing notes

Manual testing only — automated drag-and-drop testing is prohibitively platform-specific.

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This was generated by AI during triage.

Agent Brief

Goal: Add support for vertical Japanese text (tategaki). The Reading schema gains an orientation field (horizontal or vertical). The Python sidecar defaults to horizontal but includes orientation in output. The Reading Engine renders vertical text with CSS writing-mode: vertical-rl, furigana to the right of each Kanji, and Romaji horizontally beneath each column. An orientation toggle in the Reading window allows the user to switch layouts without re-running OCR.

Context:

• Slice 1-4 complete: Tauri scaffold, capture flow, Reading Engine UI, real OCR pipeline
• Domain glossary and ADRs in repo root
• PRD: PRD: NihongOCR MVP #1

Current state:

• Reading schema already has orientation field (default horizontal)
• Reading Engine renders horizontal layout with ruby furigana above Kanji
• Python sidecar returns orientation: horizontal

What to build:

1. Python sidecar: detect text orientation from PaddleOCR (textline_orientation_angles) and set orientation field accordingly
2. Reading Engine: add vertical layout rendering
   • Japanese: writing-mode: vertical-rl
   • Furigana: position to the right of Kanji (using ruby-position: right or custom markup)
   • Romaji: render horizontally beneath each vertical column
3. UI toggle: button to switch between horizontal/vertical for the current Reading
4. Toggle re-renders without re-running OCR

Key acceptance criteria:

• Vertical text detected and rendered correctly
• Furigana appears to the right of Kanji in vertical mode
• Romaji renders horizontally beneath columns
• Orientation toggle works and re-renders instantly
• Component tests cover vertical layout DOM structure

Blockers: None — Slice 4 is complete.