Folio Reader

A manuscript-grade Markdown and LaTeX reader for Android, built with Kotlin, Jetpack Compose (Material 3 You), and a Rust Native Engine.

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Highlights

• Native Rust Engine (rust-core): Blazing-fast document analysis, heading hierarchy extraction, AST tokenization, formula cataloging, and reading time computation via JNI.
• LaTeX Math Support: Sharp, hardware-accelerated rendering of inline ($..$) and display ($$..$$) mathematical equations using KaTeX.
• Material 3 You Tactile Aesthetics:
  • Full Android 12+ dynamic wallpaper color extraction (Monet).
  • Built-in tactile atmospheres: Velum Parchment, Obsidian Manuscript, Sepia Solace, and Pure AMOLED.
  • Spring-physics motion (Spring.DampingRatioLowBouncy).
• Two Reading Modes:
  • Tactile Pager Mode: 3D paper tilt and scale animations simulating heavyweight book pages.
  • Continuous Scroll Mode: Fluid vertical reading with dynamic progress pill and auto-collapsing top bar.
• Expressive Bottom Sheets:
  • Table of Contents: Indented heading navigation.
  • LaTeX Formula Inspector: Browse all equations in the document with one-tap LaTeX source copy.
  • Typography Controls: Real-time adjustment of font sizes, line spacing, and typeface families (Serif, Sans, Mono).
  • Atmosphere & Theme Selector: Instant palette preview and selection.
• SAF Document Import: Open any .md, .markdown, or .txt file directly from device storage or file managers.
• Prepackaged Showcase Documents: Includes papers on Quantum Mechanics, Riemann Hypothesis, and Material 3 Dynamics to explore right away.

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Architecture

folio-reader/
├── rust-core/                  # High-performance Rust parser crate
│   ├── Cargo.toml
│   └── src/lib.rs             # Regex AST engine & JNI bridge
├── app/
│   ├── src/main/java/com/hmndev/folioreader/
│   │   ├── core/              # Rust JNI bridge & document model
│   │   ├── ui/
│   │   │   ├── components/    # Reusable Material 3 components & sheets
│   │   │   ├── screens/       # Shelf & Reader screens
│   │   │   ├── theme/         # Color palettes, typography & spring motion
│   │   │   └── viewmodel/     # State management & document loader
│   │   └── assets/            # KaTeX engine & sample documents
└── .github/workflows/         # Automated APK builder in GitHub Actions
    └── build-apk.yml

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CI / Automated APK Builder

The GitHub Actions workflow (.github/workflows/build-apk.yml) automatically builds the native Rust .so libraries for Android (arm64-v8a, x86_64), runs the test suites, compiles the APK, and uploads it to GitHub Artifacts.

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Design Discipline

See TASTE.md for the aesthetic principles and anti-patterns guiding this project.