https://github.com/lchristmann/tracker
A geolocation tracker that lets you measure your location at regular intervals and send that data over the Internet
https://github.com/lchristmann/tracker
android android-app kotlin kotlin-android location-tracker
Last synced: 27 days ago
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A geolocation tracker that lets you measure your location at regular intervals and send that data over the Internet
- Host: GitHub
- URL: https://github.com/lchristmann/tracker
- Owner: lchristmann
- Created: 2025-02-22T12:23:30.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2025-03-10T01:27:28.000Z (over 1 year ago)
- Last Synced: 2025-08-29T02:20:35.689Z (10 months ago)
- Topics: android, android-app, kotlin, kotlin-android, location-tracker
- Language: Kotlin
- Homepage:
- Size: 668 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Tracker - An Android App
This is an Open Source Android Application, that lets you
- track your location with your Android phone and
- send that data over the Internet to a remote API
The app is embedded in a larger system, that can receive and visualize the location data in near real-time.
The project for the API can be found here: [tracker-api-aws-lambda-function](https://github.com/lchristmann/tracker-api-aws-lambda-function) (left side of diagram)
The project for the website can be found here: [tracker-website](https://github.com/lchristmann/tracker-website) (right side of diagram)
> Platform requirements: API-level 29, i.e. Android 10 (released in September 2019) or newer.
>
> **Usage of the application:**
> - when prompted, grant permissions for location and when forwarded to the Settings, **for location select "Allow all the time"** for background tracking to work.
> - grant both coarse and fine location
> - **uncheck the "Pause app activity if unused"** - just to be sure
## The App's Architecture
The app uses the [MVVM (Model View ViewModel) Architecture Pattern in Android](https://www.geeksforgeeks.org/mvvm-model-view-viewmodel-architecture-pattern-in-android/) for structure (that's the top half of the diagram).
The database part is implemented with the recommended [Room database persistency library (using the Repository pattern)](https://medium.com/swlh/basic-implementation-of-room-database-with-repository-and-viewmodel-android-jetpack-8945b364d322) that [provides a powerful abstraction layer over SQLite](https://developer.android.com/training/data-storage/room) (that's the bottom half).
## The Directory Structure
The classes displayed in above architecture diagram are organized into a proper folder structure:
```text
.
├── api
│ ├── LocationUploadRequest.kt
│ └── TrackerApiService.kt
├── data
│ ├── LocationDao.kt
│ ├── LocationDatabase.kt
│ ├── LocationData.kt
│ ├── LocationEntity.kt
│ └── LocationRepository.kt
├── LocationWorker.kt
├── MainActivity.kt
├── screens
│ ├── HomeScreen.kt
│ ├── LocationsScreen.kt
│ ├── LocationsViewModel.kt
│ ├── MapScreen.kt
│ └── TrackingViewModel.kt
└── utils
└── LocationUtils.kt
```
## How does the Location Tracking work
The location tracking works by utilizing the [Fused Location Provider API](https://developers.google.com/location-context/fused-location-provider) for Android.
Image source: heise online Artikel "[50 Jahre Notruf: So ortet die Leitstelle Ihr Mobiltelefon](https://www.heise.de/hintergrund/Notruf-112-So-ortet-die-Leitstelle-Ihr-Mobiltelefon-7490400.html?seite=5)".
As shown by default this uses Google Play Services, but for the de-googled operating system eOS, this is replaced by [MicroG](https://community.e.foundation/t/discover-microg-and-what-it-is-used-for/43418), which is an open source implementation of the Google Play Services.
## Details
The app tracks the location every 15 minutes in the background and tries to upload all locations that have not been uploaded yet on those occasions.
There's also a button to track the location once immediately and try to upload all local locations.
Then there are two activities ("screens") for visualization:
- a list view of the last 50 tracked locations
- a map view of the last 50 tracked locations (implemented with [OSMDroid](https://github.com/osmdroid/osmdroid), see [docs are here](https://github.com/osmdroid/osmdroid/wiki#kotlin))
### App Icon
The app icon is currently configured [like this](https://icon.kitchen/i/H4sIAAAAAAAAAzWQMY%2FDIAyF%2F4tvzcI1WbJ2uPWk63Y6nSA2BJXEKZBWVdX%2FXjttFzAffu%2BBb3C2aaUC%2FQ3Q5uNhpImg9zYVasCFPSfO0MPHznfGddCAD%2FsUF5urSgrJBkjerqnKZRx4FuAn%2FA%2FMCHftP1wXsYThJVPbFwrZYqT5yb7eB%2FEdNNZobmvQeC8NG%2FpU5HDXehJk55DEpu22mG%2BLGOeg8soL9KZtIMcwiqGWjmvl6Vkn8hsVnQs%2Fo90eU05rzIMYCp0Y16RT%2BZUQzBxRP8dF1gs5%2BLs%2FAFGiSo84AQAA) thanks to the [IconKitchen App Icon Generator](https://icon.kitchen).
## Development Notes
- add the API_KEY for the Tracker API to your `local.properties` file as shown below.
The implementation was done following Philipp Lackner's tutorial [How to Hide & Protect API Keys in Your Android App](https://www.youtube.com/watch?v=-2ckvIzs0nU) and this Medium article [How to safely store API keys in Android project](https://medium.com/@darayve/how-to-safely-store-api-keys-in-android-project-a-straightforward-guide-22c7fffd95e7).
```text
API_KEY=api-key-here
```
- use a new Android Studio with the new UI (made by JetBrains)
- use Logcat, Build and App Inspection to get insights (bottom left bar)
- under App Inspection there's Database Inspection
- have the "Keep database connections open" option selected there, so you can keep inspecting the database when the app has closed
- under App Inspection there's Background Task Inspector -> view my WorkManager Tasks and their status
- when having changed the LocationEntity (or in general the database schema), you must go to the device's Settings > Tracker (App) > Storage > Delete all storage (else the Room database will crash again and again, because it can't cope with the inconsistency of a changed schema)
- for debugging SharedPreferences: you can go in the top right bar to "Device Manager" and then 3 dots > Open in Device Explorer > /data/data/com.lchristmann.tracker/shared_prefs/tracking_prefs.xml and download that file (there you can see the current value of `isTracking`)
- `./gradlew clean build`, `./gradlew --version`, `./gradlew --warning-mode all`, `./gradlew build -stacktrace`
## Release
1. In Android Studio click on "Build" > "Build App Bundle(s) / APK(s)" > "Build APK(s)".
2. Once done, a notification will appear saying: "Build completed successfully for 1 module: Module 'Tracker.app': locate or analyze the APK." > click on "locate"
That's the installable APK right there (in the `app/build/outputs/apk/debug/` folder).