Weather (Android)

A small Android app that displays current weather, hourly and daily forecasts for the user's current location. Built with Jetpack Compose and following a Clean Architecture + MVVM structure.

Screenshots & Demo placeholders

light mode

your_file_name.mp4

dark mode

Screen_recording_20251005_103349.mp4

Highlights

• Single-screen Compose UI showing:
  • Current conditions (temperature, weather description, icon)
  • Hourly forecast
  • Daily forecast
  • Details cards (humidity, pressure, wind, UV index, etc.)
• Clean architecture (domain, data, presentation layers)
• MVVM with a Compose-friendly ViewModel
• Koin for dependency injection
• Ktor HTTP client + kotlinx.serialization for networking
• Uses Google Play Services Fused Location to obtain the device location
• Uses Open-Meteo (https://open-meteo.com) for weather data and OpenStreetMap Nominatim for reverse geocoding (no API key required)

Project structure

• app/src/main/java/com/thechance.weather
  • data — remote data sources (Ktor clients), local (fused) location provider, mappers
  • domain — models, repository interfaces, use cases, domain exceptions
  • presentation — Compose UI, ViewModels, UI models and themes
  • di — Koin modules wiring the app together
  • WeatherApplication — Koin initialization

Key libraries & versions (from project)

• Android Gradle Plugin: 8.10.1
• Kotlin: 2.0.21
• Jetpack Compose (BOM): 2024.09.00
• Ktor client: 3.1.3
• Koin: 4.0.4
• Google Play Services Location
• kotlinx.serialization / kotlinx.coroutines

(See gradle/libs.versions.toml and app/build.gradle.kts for full details.)

Permissions

The app requires the following runtime permissions:

• ACCESS_FINE_LOCATION / ACCESS_COARSE_LOCATION — to fetch device location via FusedLocationProvider
• INTERNET — to call the remote APIs

The AndroidManifest.xml already declares these permissions. The app's UI / ViewModel maps permission and location errors to friendly messages.

External APIs

• Weather: Open-Meteo (https://api.open-meteo.com/v1) — used by WeatherRemoteDataSourceImpl. Open-Meteo is free and does not require an API key.
• Reverse Geocoding: Nominatim (https://nominatim.openstreetmap.org) — used by GeocodingRemoteDataSourceImpl to obtain a city name. No API key needed, but please respect usage policy for heavy traffic.

No API keys or secret configuration are required to run the app.

How it works (brief)

• On start, WeatherViewModel triggers loadWeather().
• GetCurrentLocationUseCase retrieves the location from LocationRepository which uses Google Play Services (FusedLocationDataSource).
• GetWeatherUseCase calls the WeatherRepository which uses a Ktor client to fetch weather data from Open-Meteo.
• GetCityNameUseCase calls Nominatim to resolve a readable city name for display.
• The domain objects are mapped to UI state models via presentation.mapper and rendered using Jetpack Compose.

Running locally

Requirements:

• Android Studio Flamingo or newer (recommended)
• Android SDK configured for API level 36 (compileSdk 36)
• Device or emulator with Google Play services for Fused Location

Steps:

1. Open the project in Android Studio.
2. Let Gradle sync and download dependencies.
3. Build and run on an emulator or device (API 26+).

Note: The app uses Google Play Services for location. Use an emulator image that includes Google Play, or test on a real device.

Error handling

Common errors are mapped to user-facing messages in WeatherViewModel.mapErrorToMessage():

• Location permission issues
• GPS disabled
• Network / server errors
• Data parsing issues