guanghu/docs/adr/0031-full-app-for-note-windows.md

type, id, title, status, date

type	id	title	status	date
ADR	0031	Full App instance for secondary note windows	active	2026-03-31

Context

Laputa supports opening a note in a secondary window ("Open in New Window"). The original implementation used a dedicated NoteWindow component — a thin shell that rendered only the editor, duplicating some App-level logic (vault loading, settings, keyboard shortcuts) in a simplified but diverging form. As the main App gained features (properties editing, zoom, command palette, keyboard shortcuts), the NoteWindow shell fell behind, requiring ongoing maintenance to keep parity.

Decision

Remove NoteWindow and render the full App component in secondary note windows. The window type is detected at startup via URL query parameters (?window=note&path=...&vault=...). When in note-window mode, the App initialises with panels hidden (sidebar collapsed, inspector collapsed) and auto-opens the target note once vault entries load. The window title is kept in sync with the active note title via the Tauri window API.

Options considered

• Keep NoteWindow shell (status quo): lower initial bundle weight per window, but divergence grows with every main-App feature. Rejected — maintenance cost dominates.
• Full App instance with URL-param mode (chosen): complete feature parity for free; single code path for all window types. Trade-off: slightly heavier startup for secondary windows (full vault load), acceptable given local filesystem speed.
• IPC-driven secondary window (no vault reload): secondary window subscribes to primary window's vault state via Tauri events. Maximum efficiency, avoids double vault reads. Deferred — requires significant IPC plumbing; can be layered on top later without changing the rendering model.

Consequences

• Removes ~163 lines (NoteWindow.tsx deleted entirely)
• Secondary note windows get full feature parity: all keyboard shortcuts, properties panel, zoom, command palette, diff mode, raw editor
• useLayoutPanels gains an initialInspectorCollapsed option to support the hidden-panel initial state
• A new src/utils/windowMode.ts utility encapsulates URL-param detection — single source of truth for window-type logic
• Vault is loaded independently in each note window (no shared state with the main window); writes go to the same filesystem so eventual consistency is maintained via file-watching
• Triggers re-evaluation if: multiple simultaneous note windows cause measurable vault-read contention, or if IPC-driven shared-state windows become a product requirement