# MuPDF Mini Viewer

This project is a minimalist Android app that uses the MuPDF library to view
PDF, XPS, CBZ, unprotected EPUB, and FB2 documents.

The app will start with a file picker showing the contents of the external
storage directory. Only files that it can open will be listed.

Each document you open will start its own activity, so you can view many
documents at once. Use the [ ] system button to switch between the file picker
and any open documents and other activities you have running.

Tapping on the left and right side of the screen will flip to the previous and
next pages. Tapping in the middle will bring up or hide the tool bars. A long
tap will toggle highlighting of links. When the links are highlighted they are
also active and tappable.

You can pinch to zoom in. When zoomed in, tapping will scroll to advance the
next screenful of content.

In the toolbar there is a button to show the table of contents, if the document
has one. In EPUB and FB2 documents, there is also a menu item to pick the font
size. The scrubber at the bottom allows you to quickly jump to a given page in
the document.

## License

MuPDF is Copyright (c) 2006-2017 Artifex Software, Inc.

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU Affero General Public License as published by the Free
Software Foundation, either version 3 of the License, or (at your option) any
later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU Affero General Public License along
with this program. If not, see <http://www.gnu.org/licenses/>.

## Prerequisites

You need a working Android development environment, consisting of the Android
SKD and the Android NDK. The easiest way is to use Android Studio to download
and install the SDK and NDK.

## Building

Download the project using Git:

	$ git clone git://git.ghostscript.com/mupdf-android-viewer-mini.git

Edit the local.properties file to point to your Android SDK directory:

	$ echo sdk.dir=$HOME/Android/Sdk > local.properties

If all tools have been installed as per the prerequisites, build the app using
the gradle wrapper:

	$ ./gradlew assembleRelease

If all has gone well, you can now find the app APKs in app/build/outputs/apk/,
with one APK for each ABI. There is also a universal APK which supports all
ABIs.

The library component can be found in lib/build/outputs/aar/lib-release.aar.

## Running

To run the app in the android emulator, first you'll need to set up an "Android
Virtual Device" for the emulator. Run "android avd" and create a new device.
You can also use Android Studio to set up a virtual device. Use the x86 ABI for
best emulator performance.

Then launch the emulator, or connect a device with USB debugging enabled:

	$ emulator -avd MyVirtualDevice &

Then copy some test files to the device:

	$ adb push file.pdf /mnt/sdcard/Download

Then install the app on the device:

	$ ./gradlew installDebug

To start the installed app on the device:

	$ adb shell am start -n com.artifex.mupdf.mini.app/.LibraryActivity

To see the error and debugging message log:

	$ adb logcat

## Building the JNI library locally

The viewer library here is 100% pure java, but it uses the MuPDF fitz library,
which provides access to PDF rendering and other low level functionality.
The default is to use the JNI library artifact from the Ghostscript Maven
repository.

If you want to build the JNI code yourself, you will need to check out the
'jni' submodule recursively. You will also need a working host development
environment with a C compiler and GNU Make.

Either clone the original project with the --recursive flag, or initialize all
the submodules recursively by hand:

	mupdf-mini $ git submodule update --init
	mupdf-mini $ cd jni
	mupdf-mini/jni $ git submodule update --init
	mupdf-mini/jni $ cd libmupdf
	mupdf-mini/jni/libmupdf $ git submodule update --init

Then you need to run the 'make generate' step in the libmupdf directory:

	mupdf-mini/jni/libmupdf $ make generate

Once this is done, the build system should pick up the local JNI library
instead of using the Maven artifact.

## Release

To do a release you MUST first change the package name!

Do NOT use the com.artifex domain for your custom app!

In order to sign a release build, you will need to create a key and a key
store.

	$ keytool -genkey -v -keystore app/android.keystore -alias MyKey \
		-validity 3650 -keysize 2048 -keyalg RSA

Then add the following entries to app/gradle.properties:

	release_storeFile=android.keystore
	release_storePassword=<your keystore password>
	release_keyAlias=MyKey
	release_keyPassword=<your key password>

If your keystore has been set up properly, you can now build a signed release.

## Maven

The library component of this project can be packaged as a Maven artifact.

The default is to create the Maven artifact in the 'MAVEN' directory. You can
copy thoes files to the distribution site manually, or you can change the
uploadArchives repository in build.gradle before running the uploadArchives
task.

	$ ./gradlew uploadArchives

Good Luck!