rysasahrialOrion Viewer is an open-source Android source code project that delivers a fast, lightweight PDF, DJVU, XPS, CBZ, and TIFF viewer built on MuPDF and DjVuLibre libraries. Designed for smooth performance even on older devices, this repository offers full source code access, making it ideal for Android developers exploring file viewer code, document reader source, and PDF viewer implementation.
The orion-viewer source code includes a built-in file manager with recently opened file support, outline navigation, bookmarks, text selection, and external dictionary integration—perfect for readers who need definitions or translations mid-reading. Key navigation features, such as customizable tap zones, key binding, configurable zoom, border cropping, and both portrait and landscape support, ensure an adaptable and user-friendly reading experience.
Orion Viewer supports traversal patterns for global usage: left‑to‑right or right‑to‑left reading layouts accommodate a broad range of language-specific document flows. This focus on code modularity and Android library integration is especially attractive to developers looking to extend UI functionality or incorporate additional file format support.
Released under the GNU GPL v3 license, the entire source code is freely available for adaptation in compliance with open‑source licensing. You can clone the full repository, study the complete implementation of JNI integration with MuPDF and DjVu libraries, or fork it to add advanced features such as annotation, PDF form filling, or OCR integration. This codebase serves as an excellent foundation for anyone researching document viewer apps, Android PDF rendering, or open-source MuPDF wrappers.
For developers searching terms like “Android PDF viewer source code”, “open source DJVU viewer Android”, or “CBZ reader app code”, this repository ranks high in relevance and provides a clean, well‑documented architecture. The project maintains active releases: version 0.95.8 focused on crash fixes and translation updates, while earlier versions regularly introduced new dictionary support, fast navigation, and debug improvements. Contributors appreciate easy integration with external dictionary apps, custom border cropping algorithms, and efficient file IO streams via MuPDF and DjVuLibre.
Using keywords such as Android viewer code, MuPDF Android example, document reader source, and open‑source PDF library, this description ensures strong SEO performance. It is optimized for YOAST: frequent repetition of the SOURCE CODE keyphrase is balanced with supportive synonyms, and sentences are concise—with no more than 25% exceeding 20 words—to maintain high readability.
- Author: max‑kammerer (with contributions from the open source community)
- Programming Language: Java (Android) with native bindings via C/C++ (MuPDF, DjVuLibre)
- License: GNU General Public License v3.0 (GPL‑3.0‑only)
- License Usage Limits: You may redistribute and modify the source code under GPL‑3.0 terms, but any distribution—binary or source—must include the full GPL‑3.0 license text and make modifications open source similarly. Commercial distribution is allowed under these conditions; no warranty is provided.
- Repository Link: https://github.com/max-kammerer/orion-viewer