Internet Radio Flutter

A Flutter/Dart/Kotlin-based internet radio streaming application designed to run on one of my old Android phones which I connect through the headphone jack to my receiver.

Features

• Internet Radio - Stream radio stations via Android Media3 (ExoPlayer)
• Remote Control - Install the app on two devices and control one with the other
• Custom Station Library - Configure multiple radio stations with logos through a "hardcoded json" before building.
• Mute/Unmute Control - Toggle audio playback (current build mutes the stream which means it keeps consuming data, but prevents having to listen to the start commercial on resume)
• Screensaver Mode - Automatic screensaver with station artwork

Technologies

Layer	Stack	Role
UI	Flutter 3.44 / Dart 3.12	Screens, station grid, settings, remote UI
App logic	Dart	Stations, settings, TCP remote protocol, controllers
Audio	Kotlin + AndroidX Media3 1.10	Live stream playback, mute, audio routing
Bridge	MethodChannel / EventChannel	Dart ↔ native player
Persistence	shared_preferences	Mode, player IP, last station
Networking	dart:io TCP	Remote control on port 6435

Android: minSdk 26 (Android 8), target Android 14. Built-in Kotlin (AGP).

Requirements

• Flutter 3.44.2 (Dart 3.12.2)
• Android SDK / device or emulator (API 26+)
• JDK 17 (for Android Gradle builds)

Project layout (app code)

lib/
  main.dart
  app/                      # AppScope wiring
  models/                   # Pure data types (stations, settings, player/remote state)
  services/                 # Player facade, repos, TCP, wakelock, local IP
  controllers/              # RadioController
  screens/                  # MainScreen
  widgets/                  # Station grid/tile, settings overlay
android/app/src/main/kotlin/nl/siwoc/internetradio/
  MainActivity.kt
  RadioPlayerPlugin.kt      # MethodChannel / EventChannel
  RadioPlayerHolder.kt      # Shared player singleton
  RadioPlayerManager.kt     # Media3 / ExoPlayer
  RadioPlaybackService.kt   # Foreground MediaSessionService + notification
android/.../java/.../AudioRouteFixer.java
assets/
  settings.json
  images/                   # Station logos (PNG)

Configuration

Station list — assets/settings.json

Place the station list at:

assets/settings.json

Register it in pubspec.yaml under flutter: assets:.

Format:

{
  "stations": [
    {
      "name": "Station Name",
      "url": "https://stream-url.com/stream",
      "imageAssetPath": "assets/images/station-logo.png"
    }
  ]
}

• name — Display name
• url — Stream URL (MP3, Icecast, redirects, etc.; verify per station with Media3)
• imageAssetPath — Flutter asset key under assets/ (optional; UI falls back to name)

The last station in the list is the URL-test tile. Its stream URL comes from this file, or from the persisted Settings URL when that field is filled.

Station logos — assets/images/

Place logo files at:

assets/images/
  station-logo.png
  ...

Use PNG (WEBP possible if the loader supports it). If a logo is missing, the UI falls back to the station name.

Fallback stations

If settings.json fails to load, the app should use hardcoded fallbacks:

• ABC Triple J NSW
• Q-Music
• Radio 538

Controls

• Station buttons — Switch station (Player) or send remote command (Remote)
• Mute — Toggle output (stream stays connected)
• Player / Remote — Operating mode
• Settings — Player IP, connection test, URL test, display policy (Player)
• Touch — Resets screensaver timer
• Exit — Close app (Android)

License

GNU General Public License v3.0 — see LICENSE.

Notes

• Don’t add android/ as a separate workspace root. The Android module depends on the Flutter project (flutter.sdk, Flutter Gradle plugin). Opening it alone breaks Gradle import in Cursor.
• Player mode can keep the screen on (keepScreenOn display policy)
• Screensaver after ~60s inactivity
• Last station, mode, and display policy persist between sessions
• Test devices:
  • Moto G 5S Plus — 1080 × 1920 (5.5″, 16:9), Android 8
  • OnePlus Nord 2T — 1080 × 2400 (6.43″, 20:9), Android 14
• Development checklist: todo.md
• Class & folder overview: docs/class-overview.md