Module 4 — User Interface

The user-facing screens to operate the dashcam.

Tracked in #6 (dashboard) and #7 (gallery, player, share).

The design system is Material 3 (stable 1.4.0 line, no alpha-only Material 3 Expressive components) themed with a US aviation/cockpit-avionics brand palette (FlightOrange, annunciator green/amber/red, cockpit dark base), per #220. This supersedes the original stock-Material-3-only decision in #9, which PR #186 shipped without updating this document. The design-system spec of record is the living prototype at docs/design/index.html; ui/theme/Color.kt is its Compose implementation, not the other way around, and it does not yet match the spec on every token (see AGENTS.md §5 for the known divergences). See AGENTS.md §5 for the semantic colour-role rules (green = OK/recording, amber = paused/caution, red = error/warning, orange = brand CTA). Per #225, the app is permanently dark on the fixed cockpit ground (CockpitSlate / CockpitPanel), with dynamic wallpaper color disabled.

Main Dashboard

The Cockpit dashboard shows the continuous-recording switch, the “REMOVE BEFORE FLIGHT” standby tag (which can be dragged off or activated to arm the recorder, #284), a live 20-capsule VU meter in dBFS, and the circular buffer retention bar showing how much audio is currently held in RAM. Paused (microphone in use, such as during a phone call) and error states are visually and semantically distinct from recording and standby.

Main Action Buttons (Save & Live)

Inside the main engine card (#335), two avionics panel buttons control exports:

• Save (Lookback): writes the buffered audio since the last save (or the full buffer on the first save) to a local .m4a file and advances the export floor (#121, #410) so consecutive saves never overlap. Disabled with a clear “No audio yet” caption when nothing new is buffered.
• Live (Continuous forward recording): opens a new .m4a file that preserves the buffered past and keeps recording live until the user taps Stop.

Local Gallery

A list view of previously saved audio files (blackbox_*), sorted by date and time, sourced from MediaStore (MediaStoreSink.queryRecordings) so it cannot drift from what is actually on disk.

Embedded Player

In-app playback of saved files, with play/pause, a scrub bar and elapsed/total time. Playback requests audio focus and does not interfere with a recording still running in the background.

Share Action

Integration with the Android Share Intent to send an exported file to messaging apps or email, using the recording row’s MIME type (audio/mp4 for .m4a AAC exports) and granting temporary read permission to the receiver.