Orion Viewer is pdf, djvu, xps, cbz and tiff file viewer for Android devices based on MuPDF and DjVuLibre libraries

• Outline navigation
• Bookmarks support
• Page navigation by screen taps + Tap Zones + Key binding
• Text selection
• Single word selection by double tap with translation in external dictionary
• Custom zoom
• Custom border crop
• Portrait/landscape orientation
• Support different navigation patterns inside page (left to right, right to left)
• External Dictionaries support
• Built-in file manager with recently opened file view

From version 0.91.0 Orion Viewer automatically collects app crashes and app usage statistics to improve application quality. Orion Viewer doesn't collect any personal information (and doesn't pass it to any third parties).

Whatever you want! Project is open to any ideas and discussions

Project is fully or partially translated into Chinese, English, French, German, Hebrew, Italian, Russian, Spanish, Turkish and Ukrainian languages. It would be highly desirable to eliminate gaps and errors in existing translations and to translate project into new languages.

Take a look into translations page on wiki.

To build Orion Viewer you will need:

• Android Studio 2023.1+ (for development)

• android-sdk 33+

• android-ndk 23.2.8568313

• make and python3 for mupdf

• git

• downloaded native libs (mupdf, djvu):

  ./gradlew -b thirdparty_build.gradle downloadDjvu downloadAndMakeMupdf

  Build scripts for them are defined in externalNativeBuild section in gradle build files (for details see djvuModule/build.gradle and mupdfModule/build.gradle). Native libs are checked out into nativeLibs/djvu and nativeLibs/mupdf folders.

• specify path to android-sdk in local.properties (use local.properties.sample as example).

To build Android apk files run:

./gradlew :orion-viewer:assembleDebug (or assembleRelease)

It will generate apk artifacts suitable for Android 4.1+ devices.

For Android 4.0.x devices use next build commands (it also requires android-ndk 17):

./gradlew :nativeLibs:djvuModule:clean :nativeLibs:mupdfModule:clean
./gradlew :orion-viewer:assembleDebug -Porion.build.android40=true

Pre 0.80 versions are compatible with Android 2.1+ devices

In case of getting error about absent libtinfo.so.5, please install ncurses lib (libncurses5).