DogsApp

A small Android sample app that fetches and displays random dog photos from the public dog.ceo API. Built as a modern Android playground: KSP-only annotation processing, Coil 3, kotlinx.serialization, Room with Flow, and StateFlow-driven ViewModels.

Screenshots

Main grid	Dog details	Offline (cached)

The offline panel is captured with Wi-Fi and mobile data disabled and the app force-stopped: Room serves the cached list and Coil serves the previously-loaded images from its disk cache, while the status icon signals the failed refresh.

Favorites flow

Details (not favorited)	Details (favorited)	Favorites screen

Features

• Grid of random dog images, refreshable via swipe-to-refresh
• Tap a dog to open a details screen
• Offline-first: cached list + image cache survive process death and no network
• Favorite individual dogs from the details screen and browse them on a Favorites screen
• Network layer with Retrofit + kotlinx.serialization
• Local persistence with Room exposing Flow
• Dependency injection with Hilt (KSP, no Kapt)
• StateFlow-driven ViewModels collected via repeatOnLifecycle
• Navigation Component with Safe Args
• View Binding (no Data Binding XML expressions)

Tech stack

Area	Library
Language	Kotlin 2.3.21, bytecode target JVM 17
Build	Android Gradle Plugin 9.2.0, Gradle 9.4.1 (daemon JDK 21)
Annotation proc.	KSP 2.3.7 (no Kapt)
UI	View system + View Binding, Material 1.13.0
Architecture	MVVM (ViewModel + StateFlow)
DI	Hilt 2.59.2
Persistence	Room 2.8.4 (offline cache + favorites, Flow APIs)
Networking	Retrofit 2.11.0, kotlinx.serialization 1.11.0
Async	Kotlin Coroutines 1.11.0
Image loading	Coil 3.4.0 (with coil-network-okhttp)
Navigation	AndroidX Navigation 2.9.8 (Safe Args)
Lifecycle	androidx.lifecycle 2.10.0
Refresh	SwipeRefreshLayout 1.1.0

Project structure

app/src/main/java/com/example/android/dogsapp
├── common
│   ├── di/application      # Hilt module (Retrofit, Room, repository, image loader, refresh manager)
│   └── imaging             # ImageLoader interface + CoilImageLoader
├── data
│   ├── domain              # Dog (+ displayBreedName helper), DogsResponse
│   ├── network             # DogsApi (Retrofit interface)
│   ├── local               # Room: DogEntity, FavoriteEntity, DAOs, DogsDatabase, MIGRATION_1_2
│   └── repository          # DogsRepository (interface) + impl
└── ui
    ├── main                # MainFragment, MainViewModel, DogsAdapter
    ├── details             # DetailsFragment, DetailsViewModel
    ├── favorites           # FavoritesFragment, FavoritesViewModel
    └── utils               # RefreshManager / SwipeToRefreshManagerImpl

Getting started

Requirements

• Android Studio (Ladybug or newer recommended)
• JDK 21 (the Gradle daemon is pinned to 21 via gradle/gradle-daemon-jvm.properties; Gradle will auto-provision it via Foojay if you don't have it locally). App bytecode target is still JVM 17.
• Android SDK with API level 36 installed

Build & run

git clone https://github.com/Tarek-Bohdima/DogsApp.git
cd DogsApp
./gradlew assembleDebug

Then open the project in Android Studio and run the app configuration on an emulator or device (API 26+).

Tests

./gradlew test

Continuous Integration

Every pull request against master runs the Android CI workflow on ubuntu-latest: it sets up JDK 21 (matching the Gradle daemon pin), caches Gradle, builds a debug APK, and runs unit tests.

Documentation

• ARCHITECTURE.md — how the layers fit together, why we picked each piece of the stack.
• CONTRIBUTING.md — branch/PR/squash workflow, conventions, how to add a feature, PR checklist.
• CLAUDE.md — onboarding for Claude Code agents working in this repo.

Credits

Dog images provided by the free Dog CEO API.

License

Released under the MIT License.