Episteme Reader

Episteme Reader is an offline-first application designed for reading various document formats. It leverages native Android technologies and C++ libraries to provide a performant reading experience with customization capabilities.

Features:

Supported Formats

• Documents: PDF
• E-books: EPUB, MOBI, AZW3
• Text: MD, TXT, HTML

PDF Features

• Viewing Modes: Vertical Scroll and Paginated view.
• Ink Annotations: Draw directly on pages using Pen, Highlighter, and Eraser tools.
• Text Annotations: Add text notes anywhere on the page using system or custom fonts.

E-Book Features

• Parsing: Native parsing for MOBI/AZW3 via libmobi and EPUB via Jsoup.
• Customization: Adjust font size, line spacing, and margins.
• Custom Fonts: Support for importing user-provided font files (.ttf, .otf).

General

• Text-to-Speech (TTS): Read documents aloud using the system TTS engine.
• File Management: Built-in library organization.

Architecture

• UI: 100% Jetpack Compose (Material3).
• Architecture: MVVM with Unidirectional Data Flow.
• Database: Room (SQLite) for metadata and annotations.
• PDF Engine: pdfium-android (Native PDFium bindings).
• EPUB Engine: Utilizes standard WebView for vertical scrolling mode, and a custom rendering engine for paginated mode.
• Mobi Engine: Custom JNI bindings to libmobi.