Architecture Overview

The system is built on a strict Modular Layered Architecture. This ensures 100% cohesion and zero coupling between the rendering engine and the data source.

graph TD
    subgraph Presentation_Layer [UI & Presentation]
        Main[MainActivity] --> Viewer[PdfViewerScreen]
        Viewer --> Comp[Extracted UI Modules]
        Comp --> Tokens[Design Tokens]
    end

    subgraph Domain_Layer [Business Logic]
        Viewer --> Repo[BookRepository]
        Viewer --> Prefs[ReadingPreferences]
    end

    subgraph Data_Layer [Resources]
        Repo --> Config[BookConfig Model]
        Config --> Assets[PDF Assets]
    end

    style Presentation_Layer fill:#F8F1E4,stroke:#8B6914,stroke-width:2px
    style Domain_Layer fill:#F0E8D8,stroke:#6B5E4F,stroke-width:2px
    style Data_Layer fill:#E8DFCC,stroke:#5A6340,stroke-width:2px

Request & Data Flow

When a reader opens a book, the following lifecycle is executed to ensure a sub-100ms "Time to First Page."

Page Rendering Lifecycle

sequenceDiagram
    participant U as User
    participant V as ViewerScreen
    participant Util as PdfUtils
    participant R as PdfRenderer
    participant P as PdfPageRenderer

    U->>V: Selects Book
    V->>Util: Request FileDescriptor
    Util->>Util: Copy Asset to Cache (if needed)
    Util-->>V: Return Descriptor
    V->>R: Initialize Native Engine
    V->>P: Render Page 0..N
    loop Synchronized Rendering
        P->>R: openPage(index)
        R-->>P: Render Bitmap (2x Res)
        P->>P: Apply Night Mode Filter
    end
    P-->>U: Display Fluid Page

Repository Structure

The project is structured to favor feature-first discovery. Contributors can locate logic within seconds.

root/
├── .github/                # CI/CD Workflows & Templates
├── app/
│   ├── src/
│   │   ├── main/
│   │   │   ├── assets/     # Bundled PDF documents
│   │   │   └── java/ted/parchment/reader/
│   │   │       ├── data/   # Models, Prefs, Repositories
│   │   │       ├── ui/     # Themed screens & components
│   │   │       └── utils/  # Hardware/File IO Utilities
│   └── build.gradle.kts    # Modular build config
├── docs/                   # Architectural deep-dives
└── README.md               # You are here

Technical Pipeline

Build & Deployment

The project utilizes a professional GitHub Actions pipeline for every commit to ensure structural integrity.

graph LR
    Push[Push/PR] --> Lint[Linting Check]
    Lint --> Build[Debug Build]
    Build --> Test[Unit Tests]
    Test --> Result{Success?}
    Result -- Yes --> Merge[Ready to Merge]
    Result -- No --> Fix[Notify Maintainer]

Development Workflow

New contributions are welcomed. The repository is maintained with a high bar for engineering standards.

• IDE: Android Studio Ladybug+
• JDK: 17
• SDK: 36 (target), 28 (min)
• Commands:

  ./gradlew assembleDebug  # Build
  ./gradlew test           # Verify
  

Acknowledgments & Ethics

Parchment is an original work by Ahmad Hassan (B-Ted).
It is built with a commitment to privacy:

• Zero Network Calls: Your reading habits stay on your device.
• Zero Analytics: No tracking, no telemetry.
• Open Source: Licensed under Apache 2.0.

Built for the love of reading.
Engineered by Ahmad Hassan (B-Ted)