car-interface-android

CarDash

A calm, configurable Android car dashboard launcher, built with Flutter.

CarDash replaces the tablet home screen with one landscape page: a large clock, battery and Wi-Fi status, the main media-volume control, and five shortcuts — Navigation, Music, Radio, Settings and All apps. The first three are configurable; a long press picks a different installed app. External apps open full-screen using the normal Android launcher mechanism. No overlays, no root, no kiosk setup.

Early preview — implementation and UI screenshots are in progress.

Features

• One home screen — no pages, no top bar, no bottom dock; information and controls live on the home page.
• Large clock and date with the device's 12/24-hour preference.
• Battery, charging and Wi-Fi status.
• Media volume — ring, slider, step and mute controls; hardware volume keys stay in sync. This is the phone's media stream, not a private volume.
• Configurable shortcuts for Navigation, Music and Radio. Generic icons on the dashboard; real app icons in the picker and All Apps.
• All apps — searchable grid of every launchable app, launched full-screen.
• Light / Dark / Automatic theme. Automatic uses a fixed local-time window (default 19:00–07:00), editable in Settings.
• Optional PIN — four digits, stored as a salted PBKDF2 hash in Keystore-backed storage. It is requested only when the launcher process cold-starts, never when returning from an app.
• Standard Android home role — no special overlays or permissions.
• Android 10+, landscape-only, tablet-first (verified at 1280×800).
• No network permission, no accounts, no telemetry, no T&C screen.

Requirements

• Flutter 3.47.8 / Dart 3.13.7 (or a compatible newer stable release)
• Android SDK 36, build-tools 36
• JDK 21 for Gradle (the machine default is JDK 27, which is not validated)
• Android 10 (API 29) or newer device/emulator

• A landscape tablet or an emulator; the app locks itself to landscape

  export JAVA_HOME=/usr/lib/jvm/java-21-openjdk
  export ANDROID_HOME=/opt/android-sdk
  export PATH="$ANDROID_HOME/platform-tools:$PATH"
  

Quick start

flutter pub get
./tool/check.sh

# Boot the prepared 10.1" 1280×800 Android 15 tablet (headless)
./tool/emulator.sh 35

# Build, install, and make CarDash the HOME app
./tool/install.sh debug

If the emulator does not yet exist on another machine, create it with:

sdkmanager "system-images;android-35;google_apis;x86_64"
avdmanager create avd -n cardash_tablet_api35 \
  -k "system-images;android-35;google_apis;x86_64" \
  -d "10.1in WXGA (Tablet)"

The repository also has an Android 10 AVD (cardash_tablet_api29) for minimum-version checks.

Manual install

flutter build apk --debug
adb install -r build/app/outputs/flutter-apk/app-debug.apk
adb shell cmd role add-role-holder android.app.role.HOME com.wasp.cardash_launcher
adb shell am start -a android.intent.action.MAIN -c android.intent.category.HOME

On a real tablet, use Settings → General → Home app → Set as default and accept the system prompt. The in-app "Make CarDash your home app" card does the same thing. Android will not let an app force itself into the home role silently.

Using CarDash

Action	Result
Tap Navigation / Music / Radio	Open the assigned app full-screen
Long-press Navigation / Music / Radio	Pick a different installed app
Tap an unassigned shortcut	Open the app picker
Settings	Theme, home shortcuts, default-home role, PIN
All apps	Search every launchable app; tap to open
Volume ring / mute	Toggle media mute
Slider or − / +	Set media volume
Hardware volume keys	Update the on-screen control automatically

The app hides the Android status and navigation bars while CarDash is in the foreground. Swipe from an edge to reveal them temporarily; they hide again when the app resumes.

Settings

General

• Light / Dark / Auto theme.
• Auto night window (default dark from 19:00, light from 07:00).
• The three home shortcuts.
• Home role status and shortcut to the system prompt.

Security

• Set, change or remove a four-digit PIN.
• The PIN is requested only on a cold start. It does not re-lock when switching apps, after screen-off, or after returning from Navigation. This is the agreed behavior, not an oversight.
• The PIN protects the launcher UI. It is not the Android lock screen; set a device screen lock separately for device-level security.
• There is no PIN recovery. Resetting app data removes it.

Architecture

lib/
  core/        design tokens, theme controller, icons, shared widgets
  data/        models, platform services, SettingsRepository (single source of truth)
  features/
    home/      home page, shortcut grid, volume card, controllers
    apps/      All Apps, app-picker sheet
    settings/  General + Security
    lock/      PIN pad, cold-start lock screen
android/...    MainActivity, LauncherBridge, SystemBridge (Kotlin)
tool/          emulator, install, check scripts
docs/          implementation plan, design notes

• Flutter owns all UI. Kotlin only exposes package enumeration/launching, the HOME role, battery/Wi-Fi and media volume over two MethodChannels.
• SettingsRepository is the only persistence path. Controllers are ChangeNotifiers injected with provider.
• External apps are separate activities; Android has no public API to embed them inside the launcher. This app deliberately accepts full-screen launching for maximum compatibility.

Testing

flutter analyze
flutter test
./tool/check.sh

Current tests cover PIN hashing/persistence, settings persistence, theme resolution and the shortcut tile widget. Native package enumeration and the HOME role are verified on the emulator.

Compatibility and limitations

• minSdk 29 (Android 10); compile/targetSdk 36. Nothing in the design requires a newer Android release.
• Landscape only (sensorLandscape). The home page is designed for 1280×800 and remains usable at 1024×600.
• No embedded third-party app UI. Navigation/Music/Radio are launched in their own full-screen windows.
• No global play/pause control. Volume is on the home screen; playback buttons live in the media app itself.
• No weather, Bluetooth, calls or climate in this version.
• QUERY_ALL_PACKAGES is used to list all launchable apps. It is reasonable for a launcher but requires a Play policy declaration if the app is ever distributed; this is a local/sideload build for now.
• No internet permission. The app does not fetch maps, weather or updates.
• The launcher cannot replace Android's lock screen. The PIN does not protect a running session, by design.

Design

The visual language is inspired by the TrailCurrent Godwit head unit (MIT): warm neutral surfaces, a single deep-green instrument accent, large numerals and quiet line icons. It is not a copy of that UI.

• Typeface: Manrope (SIL Open Font License), bundled offline.
• Icons: Lucide (ISC), bundled as SVGs.
• Palette and tokens: lib/core/theme/app_colors.dart.

Roadmap

• Optional compact now-playing control beside the volume card.
• Configurable home layout or additional shortcut slots.
• Screenshot set in docs/screenshots/.
• Release signing configuration.
• Real-device soak test on an Android 10 car tablet.

License

This repository is currently local-only; a project license has not been chosen. Third-party asset licenses: Manrope (OFL) and Lucide (ISC). The design is inspired by TrailCurrent Godwit (MIT).