---
phase: 02-browse
plan: 01
subsystem: ui
tags: [textual, tui, datatable, vim-navigation, python]

# Dependency graph
requires:
  - phase: 01-foundation
    provides: list_items() with LEFT JOIN room/container/category names, init_db() entry point
provides:
  - Textual TUI application shell (PossessionApp) with db_path injection
  - MainScreen with DataTable showing all inventory items
  - VIM-style navigation: j/k (row up/down), G (bottom), gg (top), q (back)
  - Updated __main__.py entry point that launches TUI instead of printing
affects: [03-actions, any phase adding new screens or TUI features]

# Tech tracking
tech-stack:
  added: [textual>=0.47.0]
  patterns:
    - PossessionApp injects db_path into App instance; screens access via self.app.db_path
    - Screen composes widget tree in compose(), loads data in on_mount()
    - Multi-key sequences (gg) tracked via self._last_key state in on_key handler
    - Item row dicts stored in self._items list for future Phase 3 action access

key-files:
  created:
    - possession/tui/__init__.py
    - possession/tui/app.py
    - possession/tui/screens/__init__.py
    - possession/tui/screens/main.py
  modified:
    - possession/__main__.py

key-decisions:
  - "db_path passed into PossessionApp constructor and accessed via self.app.db_path in screens — avoids global state"
  - "Textual import deferred inside main() in __main__.py — keeps startup path clean and avoids import side effects"
  - "gg sequence tracked with _last_key string state in on_key rather than Textual action sequences — simpler and Python 3.9 compatible"
  - "textual installed via pip3 (not editable install) — pyproject.toml already declares it as dependency"

patterns-established:
  - "Screen pattern: compose() for widget tree, on_mount() for data loading"
  - "VIM bindings: BINDINGS class var for single-key, on_key() handler for multi-key sequences"
  - "Location formatting: helper function _fmt_location() returns 'Room > Container' or single part"

requirements-completed: [NAV-01]

# Metrics
duration: 2min
completed: 2026-02-24
---

# Phase 2 Plan 01: TUI Application Shell and Item List Screen Summary

**Textual TUI shell with DataTable inventory list, VIM j/k/G/gg navigation, and updated CLI entry point**

## Performance

- **Duration:** ~2 min
- **Started:** 2026-02-24T07:12:20Z
- **Completed:** 2026-02-24T07:14:02Z
- **Tasks:** 3
- **Files modified:** 5

## Accomplishments
- Full-screen Textual TUI launches when running `possession` command
- DataTable displays all inventory items with Name, Description, Location, Category, Cost columns
- VIM keybindings: j (down), k (up), G (bottom), gg (top), q (back)
- Location column formats as "Room > Container" composite or single value
- Cost column formats as "$X.XX" or blank if None
- Item dicts stored in self._items for Phase 3 action reuse

## Task Commits

Each task was committed atomically:

1. **Task 1: TUI package structure and app shell** - `5c79cb0` (feat)
2. **Task 2: Main screen with DataTable and VIM keybindings** - `66c9eee` (feat)
3. **Task 3: Wire app into CLI entry point and install dependencies** - `5b8ec4e` (feat)

## Files Created/Modified
- `possession/tui/__init__.py` - TUI package marker
- `possession/tui/app.py` - PossessionApp(App) class with db_path injection, pushes MainScreen on mount
- `possession/tui/screens/__init__.py` - Screens sub-package marker
- `possession/tui/screens/main.py` - MainScreen with DataTable, VIM keybindings, data loading in on_mount
- `possession/__main__.py` - Updated to launch PossessionApp instead of printing database path

## Decisions Made
- `db_path` passed into `PossessionApp` constructor and accessed via `self.app.db_path` in screens — no global state.
- Textual import deferred inside `main()` in `__main__.py` to keep the startup path clean.
- `gg` double-key sequence tracked with `_last_key` string field in `on_key()` handler — simpler than Textual action sequences, Python 3.9 compatible.
- textual installed via `pip3 install textual>=0.47.0` since editable install was not writable; pyproject.toml already declares the dependency.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Installed textual before Task 1 verification**
- **Found during:** Task 1 (TUI package structure)
- **Issue:** textual was not installed; `from possession.tui.app import PossessionApp` would fail
- **Fix:** Ran `pip3 install textual>=0.47.0` before running any TUI import verifications
- **Files modified:** None (dependency install only)
- **Verification:** `python3 -c "import textual"` succeeds
- **Committed in:** N/A (dependency only, not a code change)

---

**Total deviations:** 1 auto-fixed (1 blocking — missing dependency)
**Impact on plan:** Dependency install was necessary and expected; plan noted it in Task 3 but was needed earlier for Task 1 verification.

## Issues Encountered
- Task 1 verification (`from possession.tui.app import PossessionApp`) would fail before Task 2 creates `MainScreen` since `app.py` imports it at module level. Resolved by installing textual first, then verifying both tasks together after Task 2 completed. No code changes needed.

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- TUI shell is complete and importable; Phase 3 can add quick-add, edit, delete actions inside this shell
- `self._items` list in MainScreen is ready for Phase 3 to use for action targeting
- No blockers — all success criteria met

---
*Phase: 02-browse*
*Completed: 2026-02-24*
