Marked is a high-performance, lightweight Markdown reader and editor application designed exclusively for Android. Built with modern Android development practices (Kotlin, Jetpack Compose, Room Database, Preferences DataStore, and Material 3), it delivers a premium, highly aesthetic reading and editing experience for your notes.

• ⚡ Premium Markdown Rendering:
  • Dynamic typography scale supporting Sans-Serif, Serif, and Monospace families.
  • macOS Window Decorated Code Blocks: Renders high-fidelity dark-themed code boxes featuring OS window control dots, copy-to-clipboard actions, and a comprehensive One Dark syntax highlighter for various languages (Kotlin, JS, numbers, strings, annotations, and comments).
  • Editorial Blockquotes: Features a modern glassmorphic background gradient with a low-opacity large quote symbol watermark.
  • Interactive Checklists: Double-tap directly on task checkboxes within the reader view to dynamically toggle check states with smooth ripple animations.
  • Dashed Gradient Dividers: Features elegant, fading horizontal rules with a central rotated diamond shape.
• 🎨 Persistent Reader Settings: Customize your reading layout (theme presets like Sepia Cozy, Pitch Black, or Immersive, font sizes, and line-spacing multipliers) persisted seamlessly across restarts using Jetpack Preferences DataStore.
• 📂 Local Storage: Auto-saves your notes locally in a structured SQLite database using Room.
• 📤 Document Export:
  • Generates theme-matching, print-ready HTML files with built-in URL sanitization to prevent injection vectors.
  • Supports instant PDF rendering and printing via the Android PrintManager.
• 🔒 Security Hardening: Includes scoped FileProvider path restrictions and customized cloud/device data transfer exclusion policies.

The project has been fully refactored to separate visual compositions from business logic:

app/src/main/java/com/example/
│
├── MainActivity.kt                  # App entry point, coordinates edge-to-edge Scaffold & top bar
│
├── data/                            # Room database persistence layer
│   ├── AppDatabase.kt
│   ├── MarkdownDao.kt
│   ├── MarkdownDocument.kt          # Entity modeling note data & metadata
│   └── MarkdownRepository.kt
│
├── ui/
│   ├── components/                  # Modular, decoupled visual components
│   │   ├── SidebarContent.kt        # Folder structure navigation and search drawer
│   │   ├── MarkdownEditorArea.kt    # Input area with formatting helper toolbar
│   │   ├── ReadingPreferencesDialog.kt # Layout configuration menu
│   │   └── DocumentDialogs.kt       # Create, Rename, and Delete note overlays
│   │
│   ├── markdown/                    # Markdown processing engine
│   │   ├── MarkdownParser.kt        # Custom line-by-line markdown AST parser
│   │   ├── MarkdownRenderer.kt      # Renders abstract blocks into Compose UI components
│   │   ├── MarkdownExporter.kt      # Compiles documents to styled HTML / WebView PDF
│   │   ├── ReaderPreferencesStore.kt # DataStore preference serialization
│   │   └── ReaderPreferences.kt
│   │
│   └── theme/                       # Material 3 typography and palette tokens

• Android Studio Ladybug (or newer)
• JDK 17 or 21 (Gradle build runs automatically with Java 21)
• Android SDK 36

1. Clone the repository and open the project in Android Studio.
2. Setup environment variables: Create a .env file in the project's root folder and specify your Gemini API key (though the core app works offline):

   GEMINI_API_KEY=your_gemini_api_key_here

3. Automatic Keystore Decoding: The build script is pre-configured to automatically decode the versioned debug.keystore.base64 signing asset into debug.keystore during the Gradle configuration phase. No manual keystore generation or build.gradle modifications are required.
4. Run: Connect an Android Virtual Device (AVD) or a physical developer device via ADB, and select Run app.