Technical Report: Rho Studio UI

An Android Jetpack Compose app.

Document Version: 2.0 Last Updated: August 10, 2026

Enterprise-Grade Android Architecture with Jetpack Compose

This document provides a comprehensive technical overview of the Rho Studio UI application. It serves as the primary architectural reference for developers, outlining the system's design, layer responsibilities, and technical standards.

1. Executive Summary

Rho Studio UI is the base application template designed to establish and enforce the Rho Studio Android App Standards. It provides a robust foundation for building secure, authenticated mobile experiences within the Rho Studio ecosystem.

The application is a pure Jetpack Compose implementation following a Single-Activity Architecture, leveraging a reactive MVVM (Model-View-ViewModel) pattern to ensure a clean separation of concerns, testability, and a fluid user experience driven by Unidirectional Data Flow (UDF). This architectural foundation ensures a focus on Fluid UX, Transactional Integrity, and Decoupled Business Logic.

Core Features:

Secure Authentication: Robust login flow with real-time validation and session lifecycle management, following corporate security protocols.
Adaptive Home Experience: A responsive home interface that dynamically adjusts to different service modules and device form factors.
Brand Consistency: A centralized design system leveraging Material 3 to reflect the Rho Studio corporate identity across all derived applications.

2. Architectural Framework

The application follows a Single-Activity Architecture and is structured according to Clean Architecture principles. It utilizes a Feature-Layered Modularization strategy to ensure scalability and maintainability.

2.1 Layered Structure

The system is divided into three primary logical layers, enforcing a strict unidirectional dependency flow: UI → Domain ← Data.

graph TD
    subgraph "UI Layer (Presentation)"
        UI[Jetpack Compose Screens]
        VM[ViewModels]
        Nav[Navigation / NavHost]
    end

    subgraph "Domain Layer (Business Logic)"
        UC[Use Cases / Interactors]
        Entities[Domain Entities]
        Int[Repository Interfaces]
    end

    subgraph "Data Layer (Infrastructure)"
        Repo[Repository Implementations]
        SM[Session Manager]
        Local[Local / Network Data Sources]
    end

    UI --> VM
    VM --> UC
    UC --> Entities
    UC --> Int
    Repo -.-> Int
    Repo --> SM
    Repo --> Local

2.2 Multi-Module Topology

We have moved away from a monolithic :app structure to a Feature-Layered Modularization strategy. This optimizes build parallelization and enforces strict dependency inversion.

flowchart TD
    APP[":app<br/>MainActivity, NavHost"]
    
    AUTH[":features:auth<br/>LoginScreen, LoginViewModel"]
    HOME[":features:home<br/>HomeScreen, HomeViewModel"]
    
    UI_CORE[":core:ui<br/>Theme, Common Composables"]
    DOMAIN[":core:domain<br/>Use Cases, Models, Contracts"]
    DATA[":core:data<br/>Repositories, SessionManager"]
    
    APP --> AUTH
    APP --> HOME
    
    AUTH --> UI_CORE
    AUTH --> DOMAIN
    HOME --> UI_CORE
    HOME --> DOMAIN
    
    UI_CORE --> DOMAIN
    
    DOMAIN -.->|"implemented by"| DATA
    
    style APP fill:#e94560,stroke:#c62828,color:#ffffff
    style AUTH fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style HOME fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style UI_CORE fill:#16213e,stroke:#0f3460,color:#ffffff
    style DOMAIN fill:#0f3460,stroke:#16213e,color:#ffffff
    style DATA fill:#1a1a2e,stroke:#e94560,color:#ffffff

Key Principle: :features depend only on :core modules (:core:domain, :core:ui), preventing circular dependencies. Feature-specific models remain within their respective feature modules, adhering to the Interface Segregation Principle.

3. Layer Detail & Responsibilities

3.1 UI Layer (Presentation)

Goal: Transform application state into a visual interface and handle user interactions.

Jetpack Compose: All UI is declarative, using stateless composables for maximum testability.
MVVM Pattern: ViewModels manage UI state using StateFlow, exposing it to the UI in a lifecycle-aware manner.
UDF (Unidirectional Data Flow): User actions trigger events in the ViewModel, which updates the state, triggering a UI recomposition.
Side-Effect Orchestration: MainActivity uses LaunchedEffect keyed to authentication state, transforming state changes into one-time navigation events.
Key Components:
- MainActivity.kt: The entry point and navigation orchestrator.
- LoginViewModel.kt & HomeViewModel.kt: Feature-specific state holders.
- BaseViewModel.kt: Provides shared logic for loading states, error handling, and navigation side-effects.
- HeaderViewModel.kt: Bridges SessionManager state to common UI components

flowchart TB
    subgraph Navigation["Navigation Orchestration"]
        MA["MainActivity.kt<br/>- NavHost<br/>- Session-based routing"]
    end
    
    subgraph Shared["Shared UI Components"]
        PV["BaseViewModel.kt<br/>- Loading states<br/>- Error handling"]
        HV["HeaderViewModel.kt<br/>- Session state bridging"]
        PH["PageHeader.kt"]
        PF["PageFooter.kt"]
    end
    
    subgraph Auth["Authentication Feature"]
        LS["LoginScreen.kt"]
        LVM["LoginViewModel.kt<br/>- Form state<br/>- Debounced validation"]
    end
    
    subgraph Home["Home Feature"]
        HS["HomeScreen.kt"]
        HVM["HomeViewModel.kt<br/>- Home state<br/>- Session termination"]
    end
    
    MA --> LS
    MA --> HS
    LS --> LVM
    HS --> HVM
    LVM --> PV
    HVM --> PV
    HV --> PV
    
    style Navigation fill:#e94560,stroke:#c62828,color:#ffffff
    style Shared fill:#16213e,stroke:#0f3460,color:#ffffff
    style Auth fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style Home fill:#1a1a2e,stroke:#e94560,color:#ffffff

3.2 Domain Layer (Business Logic)

Goal: House the platform-agnostic business rules and "truth" of the application.

Pure Kotlin: This layer has zero dependencies on the Android Framework (no Context, no Parcelable).
Use Cases (Interactors): Each business action is encapsulated in a dedicated Use Case (e.g., LoginUseCase). This promotes the Single Responsibility Principle and makes logic reusable across ViewModels.
Entities: Data classes like User and Credentials represent the core business models.
Key Components:
- BaseUseCase<P, R>: Standardizes execution context (Coroutines) and error handling.
- SessionManagerInterface: Defines the contract for session operations without revealing implementation details.
- LoginUseCase: Encapsulates the authentication transaction.
- LogoutUseCase: Orchestrates atomic session teardown.

3.3 Data Layer (Infrastructure)

Goal: Manage data acquisition, persistence, and external service coordination.

Repository Pattern: Acts as a mediator between different data sources (Network, Database) and the Domain Layer.
Session Management: SessionManager serves as the Single Source of Truth (SSOT) for the user's authentication state, exposing StateFlow<AuthState> for the UI to observe.
Current Implementation: Uses SharedPreferences with Gson serialization for persistence and mock authentication for development.
Key Components:
- SessionManager.kt: Singleton coordinator for authentication state and user profile.
- SessionRepository.kt: Coordinates data retrieval strategies.
- SessionRepositoryImpl.kt: Manages persistent storage using SharedPreferences. Migrated to Room Database in the future.
- AuthRepositoryImpl.kt: Mock implementation (temporary) simulating network delay and user creation. Replaced by Firebase Auth in the future.

flowchart TB
    subgraph SSOT["Single Source of Truth"]
        SM["SessionManager.kt<br/>- AuthState Flow<br/>- updateSession()<br/>- clearSession()"]
    end
    
    subgraph Repos["Repository Implementations"]
        ARI["AuthRepositoryImpl<br/>- Mock login()"]
        SRI["SessionRepositoryImpl<br/>- SharedPreferences"]
    end
    
    subgraph Sources["Data Sources (Planned)"]
        Remote["Remote API<br/>- Firebase Auth"]
        Local["Local Storage<br/>- Room Database"]
    end
    
    SM --> SRI
    ARI --> Remote
    SRI --> Local
    
    style SSOT fill:#e94560,stroke:#c62828,color:#ffffff
    style Repos fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style Sources fill:#0f3460,stroke:#16213e,color:#ffffff

4. Technical Implementation Standards

4.1 Reactive Orchestration

The application uses Kotlin Coroutines and Flow for all asynchronous operations.

State-Driven Navigation: MainActivity observes SessionManager.isAuthenticated; state changes trigger navigation transitions via LaunchedEffect.
Debounced Validation: Login inputs are validated using a 300ms debounce to optimize performance.
State Pushing: ViewModels push immutable state objects to the UI, ensuring that recompositions are predictable and efficient.

sequenceDiagram
    participant UI as MainActivity
    participant SM as SessionManager
    participant Nav as NavController
    
    UI->>SM: collectAsState()
    SM-->>UI: AuthState (Unauthenticated)
    UI->>Nav: navigate to Login
    
    Note over UI,Nav: User clicks Login
    UI->>LoginViewModel: onLoginClicked()
    LoginViewModel->>LoginUseCase: login(email, password)
    LoginUseCase->>AuthRepository: login(credentials)
    AuthRepository-->>LoginUseCase: User
    LoginUseCase->>SessionManager: updateSession(user)
    
    SM-->>UI: AuthState (Authenticated)
    UI->>Nav: navigate to Home

4.2 Modularization Strategy

The project is split into granular Gradle modules to improve build times and enforce architectural boundaries:

:app: The main coordinator and DI root.
:features:*: Feature-specific UI and ViewModels (e.g., :features:auth, :features:home).
:core:ui: Shared design system components and theming.
:core:domain: The platform-agnostic business layer.
:core:data: Implementation details for data and external services.

4.3 Design System

Located in :core:ui, the design system defines the application's visual language:

Typography: Custom typeface integration.
Color Palette: Strict adherence to the Rho Studio brand (RhoRed, RhoStrongGray).
Components: A library of reusable, styleable components (Buttons, Inputs, Cards).

5. Roadmap & Evolution: Strategic Phases

The application is transitioning from a modular prototype to a production-hardened system. The evolution is structured into three strategic phases:

Phase I: Dependency Orchestration & Decoupling

Dagger Migration: Implementation of Dagger 2 to replace manual Service Locators.
- Define @Component and @Module boundaries for :core and :features.
- Implement @Inject for UseCase and ViewModel construction to ensure compile-time dependency safety.
Interface Segregation: Strict enforcement of domain-defined interfaces to further isolate the Data Layer from Business Logic.

Phase II: Transactional Integrity & persistence

Advanced Token Management:
- Implementation of an atomic token refresh mechanism within the Data Layer.
- Securing critical transaction flows by validating session integrity before high-stakes domain executions.
- Complete token lifecycle: Acquisition → Persistence → Validation → Refresh → Recovery → Invalidation.
Offline-First with Room:
- Integration of Room Database as the local cache for service modules.
- Implementation of a "Source of Truth" strategy in Repositories to handle network-to-local synchronization.

flowchart TD
    A[1. Acquisition<br/>LoginUseCase --> AuthRepository.login]
    B[2. Persistence<br/>SessionRepository.saveToken]
    C[3. Validation<br/>ValidateTokenUseCase]
    D[4. Refresh<br/>RefreshTokenUseCase]
    E[5. Recovery<br/>SessionManager.initializeSession]
    F[6. Invalidation<br/>LogoutUseCase]
    
    A --> B --> C
    C -->|"Valid"| G[Use Access Token]
    C -->|"Expired"| D --> B
    E --> C
    F --> H[Reset AuthState]
    
    style A fill:#e94560,stroke:#c62828,color:#ffffff
    style B fill:#16213e,stroke:#0f3460,color:#ffffff
    style C fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style D fill:#0f3460,stroke:#16213e,color:#ffffff
    style E fill:#16213e,stroke:#0f3460,color:#ffffff
    style F fill:#e94560,stroke:#c62828,color:#ffffff
    style G fill:#0f3460,stroke:#16213e,color:#ffffff
    style H fill:#1a1a2e,stroke:#e94560,color:#ffffff

Phase III: Verification & Quality Engineering

Domain Test Suite: Achieving 90%+ coverage for :core:domain logic using JUnit 5 and MockK.
UI & Regression Testing:
- Implementation of Compose UI Tests for critical user journeys (Login, Home navigation).
- Integration of Screenshot Testing to ensure visual consistency across the Rho Studio design system.
Performance Profiling: Regular benchmarking of recomposition counts and memory allocation in high-density feature screens.

flowchart LR
    subgraph Current["Current Flow"]
        C1[UI] --> C2[ViewModel] --> C3[UseCase] --> C4[Repository] --> C5[SharedPreferences/Mock Auth]
    end
    
    subgraph Planned["Planned Flow"]
        P1[UI] --> P2[ViewModel] --> P3[UseCase] --> P4[Repository]
        P4 --> P5[Local: Room Database]
        P4 --> P6[Remote: Retrofit/Firebase]
    end
    
    Current -.->|"Evolution"| Planned
    
    style Current fill:#1a1a2e,stroke:#e94560,color:#ffffff
    style Planned fill:#0f3460,stroke:#16213e,color:#ffffff

6. Verification & Quality Assurance

CI/CD: GitHub Actions pipeline verifies every commit against build and test suites.
Static Analysis: Automated linting and ASCII metadata headers enforce code style and legal standards.

7. File Registry and responsibilities

Here is the updated table based on the file structure provided:

File / Module	Layer	Responsibility	Status
`MainActivity.kt`	UI Layer	Navigation orchestration	✅
`BaseViewModel.kt`	UI Layer	Loading/Error state management	✅
`HeaderViewModel.kt`	UI Layer	Session state bridging	✅
`PageHeader.kt` / `PageFooter.kt`	UI Layer	Shared UI components	✅
`LoginScreen.kt`	UI Layer	Login UI entry point	✅
`LoginViewModel.kt`	UI Layer	Form state & validation	✅
`LoginEmailField.kt`	UI Layer	Email input with validation	✅
`LoginPasswordField.kt`	UI Layer	Password input with security	✅
`LoginButton.kt`	UI Layer	Login action button	✅
`HomeScreen.kt`	UI Layer	Home UI entry point	✅
`HomeViewModel.kt`	UI Layer	Home state & session termination	✅
`ServiceList.kt`	UI Layer	Service list grid component	✅
`ServiceItem.kt`	UI Layer	Individual service item component	✅
`ServiceModule.kt`	UI Layer	Feature-specific model (Home)	✅
`BaseUseCase.kt`	Domain Layer	Standardized UseCase abstraction	✅
`LoginUseCase.kt`	Domain Layer	Atomic authentication transaction	✅
`LogoutUseCase.kt`	Domain Layer	Session teardown orchestration	✅
`SessionManagerInterface.kt`	Domain Layer	Session operations contract	✅
`AuthRepository.kt`	Domain Layer	Authentication contract	✅
`SessionRepository.kt`	Domain Layer	Session persistence contract	✅
`User.kt` / `Credentials.kt`	Domain Layer	Pure Kotlin Entities	✅
`SessionManager.kt`	Data Layer	SSOT for authentication	✅
`AuthRepositoryImpl.kt`	Data Layer	Mock auth (Firebase planned)	⚠️
`SessionRepositoryImpl.kt`	Data Layer	SharedPreferences (Room planned)	⚠️
`RefreshTokenUseCase.kt`	Domain Layer	Token refresh (planned)	📅
`Dagger Components`	App Root	DI setup (planned)	📅

8. References & Standards

MAD (Modern Android Development): Adhering to official Android Architecture Guidelines.
Jetpack Compose Best Practices: Following UDF (Unidirectional Data Flow) principles for state management.
Multi-Module Topology: Following Guide to App Modularization.
Dependency Injection: Dagger Documentation.
Secure Token Management: Android Security Best Practices.

Rho.Studio® - Engineering Department - Contact alexis.tercero@rho.studio

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
app		app
core		core
features		features
gradle		gradle
.gitignore		.gitignore
CONTRIBUTION.md		CONTRIBUTION.md
LICENSE		LICENSE
README.md		README.md
build.gradle.kts		build.gradle.kts
gradle.properties		gradle.properties
gradlew		gradlew
gradlew.bat		gradlew.bat
local.properties		local.properties
settings.gradle.kts		settings.gradle.kts

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Technical Report: Rho Studio UI

Enterprise-Grade Android Architecture with Jetpack Compose

1. Executive Summary

Core Features:

2. Architectural Framework

2.1 Layered Structure

2.2 Multi-Module Topology

3. Layer Detail & Responsibilities

3.1 UI Layer (Presentation)

3.2 Domain Layer (Business Logic)

3.3 Data Layer (Infrastructure)

4. Technical Implementation Standards

4.1 Reactive Orchestration

4.2 Modularization Strategy

4.3 Design System

5. Roadmap & Evolution: Strategic Phases

Phase I: Dependency Orchestration & Decoupling

Phase II: Transactional Integrity & persistence

Phase III: Verification & Quality Engineering

6. Verification & Quality Assurance

7. File Registry and responsibilities

8. References & Standards

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Technical Report: Rho Studio UI

Enterprise-Grade Android Architecture with Jetpack Compose

1. Executive Summary

Core Features:

2. Architectural Framework

2.1 Layered Structure

2.2 Multi-Module Topology

3. Layer Detail & Responsibilities

3.1 UI Layer (Presentation)

3.2 Domain Layer (Business Logic)

3.3 Data Layer (Infrastructure)

4. Technical Implementation Standards

4.1 Reactive Orchestration

4.2 Modularization Strategy

4.3 Design System

5. Roadmap & Evolution: Strategic Phases

Phase I: Dependency Orchestration & Decoupling

Phase II: Transactional Integrity & persistence

Phase III: Verification & Quality Engineering

6. Verification & Quality Assurance

7. File Registry and responsibilities

8. References & Standards

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