AndroidPlayground

Android Playground Samples

This repository contains implementations of various system design patterns and concepts commonly used in Android development. Each topic demonstrates real-world scenarios and best practices for building scalable, maintainable Android applications.

Development Tools

This project uses several tools to maintain code quality and consistency:

• ktlint = formatting & style (auto-fixable)
• Detekt = code quality, correctness & architecture (non-trivial fixes)

Project Setup

To set up the project and enable automatic code quality checks:

1. Clone the repository:

   git clone <repository-url>
   cd "Android Playground"

2. Install the git pre-commit hook:

   ./gradlew installGitHooks

   Or set up the entire project at once:

   ./gradlew setupProject

Additional Git Hook Management Commands

• Check git hook status: ./gradlew checkGitHooks
• Uninstall git hooks: ./gradlew uninstallGitHooks

The git hook will automatically run code quality checks (ktlint formatting and Detekt analysis) before each commit, ensuring code consistency across the project.

Features

1. Feed

Home screen listing all available topics as navigable cards.

MVI contracts: FeedState · FeedIntent · FeedSideEffect

Feed Screen

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2. Image Upload

Multi-image upload with per-item progress tracking and success/failure status cards.

MVI contracts: ImageUploadState · ImageUploadIntent · ImageUploadSideEffect

Image Upload Screen

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3. Login

Authentication screen with email/password form, input validation, visibility toggle, and loading/error states.

MVI contracts: LoginState · LoginIntent · LoginSideEffect

Login Screen

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4. Note (Todo CRUD)

Full create/read/update/delete note app with search and Room-backed persistence.

Screens: Note List · Note Detail

MVI contracts: NoteListState · NoteListIntent · NoteListSideEffect · NoteDetailState · NoteDetailIntent · NoteDetailSideEffect

Note List	Note Detail

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5. Crypto Security

Educational demos for Android security concepts: Android Keystore key management, Google Tink encryption, secure networking, and hybrid RSA-OAEP + AES-256-GCM payload encryption.

Screens: Home · Keystore Storage Demo · Tink Storage Demo · Secure Network Demo · Send Encrypted to Server

Crypto Home	Keystore Demo	Tink Demo	Secure Network	Send Encrypted

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6. Media Orchestrator

WorkManager-based media processing pipeline. Add media items, enqueue an orchestrator worker, and observe per-item processing progress via Room.

MVI contracts: MediaOrchestratorState · MediaOrchestratorIntent · MediaOrchestratorSideEffect

Media Orchestrator Screen

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7. User-Initiated Service

Demonstrates long-running background transfers using both the legacy JobScheduler API and the modern WorkManager API, with a side-by-side comparison table.

MVI contracts: UserInitiatedServiceState · UserInitiatedServiceIntent · UserInitiatedServiceSideEffect

User-Initiated Service Screen

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GitHub Copilot Agents

This project ships a custom Copilot agent for code review.

Android Code Reviewer

File: .github/agents/android-code-review.agent.md

Reviews Kotlin and Jetpack Compose code against the project's established conventions. Covers MVI pattern, Screen/Content split, UI component rules, naming conventions, Timber logging, data layer conventions, clean architecture violations, and api module structure.

Invoke with:

@Android Code Reviewer feature/note/impl
@Android Code Reviewer NoteListScreen.kt
@Android Code Reviewer review this file

Violations are reported as:

• 🔴 Error — would fail CI or violates a hard architectural rule
• 🟡 Warning — stylistic deviation or best-practice gap