---
phase: 05-live-show-execution
plan: 03
subsystem: ui
tags: [keyboard-shortcuts, vanilla-js, undo-redo, audio, websocket]

# Dependency graph
requires:
  - phase: 05-01
    provides: "Cue scheduler backend for play/pause/seek server messages"
  - phase: 05-02
    provides: "Preview strips for seek-clear pattern"
provides:
  - "wireKeyboard() — all 7 keyboard bindings (Space, ArrowLeft, ArrowRight, Ctrl+Z, Ctrl+Shift+Z, Ctrl+Y, Ctrl+S)"
  - "Mouse-free operation of all primary actions per UI-03 requirement"
affects: []

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Keyboard guard pattern: check activeElement tagName before acting (input/select/textarea bypass)"
    - "Space-on-button guard: explicit check for tag === 'button' to prevent double-toggle"
    - "Ctrl+S round-trip save: GET current show state → POST to /api/shows (manual trigger)"
    - "Arrow seek with strip clear: same clear pattern as mouseup seek from Plan 02"

key-files:
  created: []
  modified:
    - lightsync/frontend/app.js

key-decisions:
  - "e.preventDefault() called first in every branch — suppresses Space scroll, Arrow scroll, Ctrl+S browser dialog before any logic"
  - "Space explicitly guarded on button elements to avoid double-toggle with button click handler"
  - "Ctrl+S uses GET-then-POST round-trip (reads current server state, not just timeline) — consistent with existing save pattern"

patterns-established:
  - "wireKeyboard() placed after wireAudio() in init section — both audio wiring functions called together at startup"
  - "Arrow seek clears preview strips inline — same pattern as mouseup seek handler"

requirements-completed: [UI-03]

# Metrics
duration: 10min
completed: 2026-04-07
---

# Phase 05 Plan 03: Keyboard Shortcuts Summary

**wireKeyboard() function wired with all 7 keyboard bindings (Space play/pause, Arrow seek, Ctrl+Z/Y undo/redo, Ctrl+S save) — all primary operations accessible without mouse**

## Performance

- **Duration:** ~10 min
- **Completed:** 2026-04-07
- **Tasks:** 1
- **Files modified:** 1

## Accomplishments

- Added `wireKeyboard()` function to `lightsync/frontend/app.js` (72 lines inserted)
- Space toggles audio play/pause and sends `{ type: 'play' }` or `{ type: 'pause' }` to server via WebSocket
- ArrowLeft seeks back 5 seconds, ArrowRight seeks forward 5 seconds — both send `{ type: 'seek', position }` to server and clear all preview strips
- Ctrl+Z calls `timeline?.history.undo()` via optional chaining (safe when timeline not yet initialized)
- Ctrl+Shift+Z and Ctrl+Y both call `timeline?.history.redo()`
- Ctrl+S prevents browser Save dialog via `e.preventDefault()`, then fetches current show and POSTs it back to `/api/shows`
- All shortcuts are suppressed when `document.activeElement` is an `input`, `select`, or `textarea`
- Space is additionally suppressed when focused element is a `button` to prevent double-toggle with click handler
- `wireKeyboard()` called at init after `wireAudio()`

## Task Commits

1. **Task 1: Add wireKeyboard() function and call it at init** - `3562652` (feat)

## Files Created/Modified

- `lightsync/frontend/app.js` — Added wireKeyboard() function (72 lines) and wireKeyboard() init call

## Decisions Made

- `e.preventDefault()` is called at the start of every key branch to guarantee browser defaults are suppressed before any application logic runs
- Space on `<button>` elements is explicitly skipped to prevent the double-toggle issue (keyboard Space activates focused buttons naturally; without the guard, Space would trigger both the button click and the wireKeyboard toggle)
- Ctrl+S uses a GET-then-POST round-trip rather than saving the in-memory timeline state directly — this ensures the server's current show state is preserved (consistent with existing auto-save pattern in commands.js)

## Deviations from Plan

None — plan executed exactly as written. All acceptance criteria met on first implementation pass.

## Known Stubs

None — all keyboard actions wire to real audio element methods, real WebSocket messages, and real undo/redo history calls.

---

*Phase: 05-live-show-execution*
*Completed: 2026-04-07*