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name: android description: Build, review, and refactor Android mobile apps (Kotlin) using modern Android patterns. Use for tasks like setting up Gradle modules, Jetpack Compose UI, navigation, ViewModel/state management, networking (Retrofit/OkHttp), persistence (Room/DataStore), DI (Hilt/Koin), testing, performance, release builds, and Play Store readiness.

android

Use this skill when working on Android client (大前端 / 移动端) codebases.

Defaults (unless repo dictates otherwise)

• Language: Kotlin
• UI: Jetpack Compose (if legacy XML exists, follow existing structure)
• Architecture: MVVM + unidirectional data flow (UDF)
• Async: Kotlin Coroutines + Flow
• DI: Hilt if present; otherwise keep consistent with current

Project structure (recommended)

• app/: application module (entry, navigation, composition root)
• core/: shared utilities and platform abstractions (optional)
• data/: API + persistence implementations
• domain/: use-cases, business models (pure Kotlin)
• feature/<name>/: feature modules or packages (UI + presentation)

Workflow

1. Establish constraints

• Min/target SDK, build system, existing modules.
• Compose vs XML, single-module vs multi-module.

1. Define app flows

• Identify screens and navigation graph.
• Define state models per screen and their events/actions.

1. Data layer design

• API models vs domain models (mapping boundaries).
• Retrofit service interfaces + OkHttp interceptors (auth, logging).
• Caching strategy: memory vs disk (Room/DataStore).

1. UI & state

• Compose: keep Composables stateless where possible; state hoisted to ViewModel.
• ViewModel exposes StateFlow<UiState> and accepts events/intents.
• Handle loading/error/empty states explicitly.

1. Error handling

• Normalize errors (network, auth, validation) to domain-friendly types.
• Avoid leaking Retrofit/Room types into UI.

1. Performance & UX

• Avoid recomposition traps; use stable models and remember.
• Images: Coil; pagination for long lists; debounce inputs.
• Accessibility basics: content descriptions, large text support.

1. Quality gates

• Unit tests for domain and ViewModels.
• UI tests where meaningful (Compose testing).
• Lint/detekt/ktfmt if configured; keep build green.

Output expectations when making changes

• Keep diffs localized; avoid broad refactors unless requested.
• Add/adjust tests when changing behavior.
• For new features: include navigation entry, UI state contract, and data wiring.