V Android Bootstrapper

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V Android Bootstrapper is the currently supported way to compile, package, sign and deploy V graphical apps on Android based devices. It can be used as a V module (import vab) and also provides a standalone executable (vab) for building apps from the command-line.

Install

Linux, macOS and Windows build hosts are supported.

Unix (Linux, macOS)

v install vab
v ~/.vmodules/vab

Windows

v install vab
v %USERPROFILE%\.vmodules\vab

Symlink (optional)

You can symlink vab to your $PATH so it works as a global shell command.

sudo ln -s /path/to/vab /usr/local/bin/vab

Shell tab completion (optional)

You can install tab completions for your shell by following the instructions here.

Usage

vab can be used both from the command line and as a module in V code. In either case the following dependencies is required before vab will work as intented.

Runtime dependencies

• V
• Java (JDK) >= 8 (>= 9 on Windows)
• Android SDK
• Android NDK

(Android Studio is NOT required)

If vab fail to detect your environment you can set ENV variables to help it:

JAVA_HOME=/path/to/java-jdk
SDKMANAGER=/path/to/sdkmanager
ANDROID_SDK_ROOT=/path/to/android_sdk_linux
ANDROID_NDK_ROOT=/path/to/android_ndk_linux
VEXE=/path/to/custom/v/binary

Development (debug builds)

The fast way from V source to an APK is:

vab /path/to/v/source/file/or/dir

... yes, that's it. Your APK should now reside in the current directory.

The fast way from source to a run on the device (build, package, deploy and launch app on device) is:

vab run --device auto --archs 'armeabi-v7a' /path/to/v/source/file/or/dir

The --archs flag control what architectures your app is built for. You can specify multiple archs with --archs 'armeabi-v7a, arm64-v8a'. By default vab will build for all 4 supported CPU architectures (arm64-v8a, armeabi-v7a, x86 and x86_64).

Release

You can build an Android app ready for the Play Store with the following command:

export KEYSTORE_PASSWORD="pass"
export KEYSTORE_ALIAS_PASSWORD="word"
vab -prod --name "V App" --package-id "com.example.app.id" --icon-mipmaps --icon /path/to/file.png  --version-code <int> --keystore /path/to/sign.keystore --keystore-alias "example" /path/to/v/source/file/or/dir

Do not submit apps using default values. Please make sure to adhere to all guidelines of the app store you're publishing to.

AAB package format

vab supports outputting Android App Bundles (AAB). To output an .aab file you can specify the package format with the --package flag:

vab --package aab /path/to/v/source/file/or/dir

Alternatively it will be inferred if you use the --output/-o flag:

vab -o /tmp/ma_app.aab /path/to/v/source/file/or/dir

Environment variables

If vab should fail to detect a tool or location on your build host you can use the following ENV variables to help vab understand your Android development setup.

Complete list of env variables recognized

VEXE                     # Absolute path to the V executable to use
JAVA_HOME                # Absolute path to the Java install to use
SDKMANAGER               # Absolute path to the sdkmanager to use
ANDROID_SERIAL           # ID of the device to deploy to
ANDROID_SDK_ROOT         # Absolute path to the Android SDK
ANDROID_NDK_ROOT         # Absolute path to the Android NDK
KEYSTORE_PASSWORD        # Password for keystore
KEYSTORE_ALIAS_PASSWORD  # Password for keystore alias
BUNDLETOOL               # Absolute path to the bundletool to use
AAPT2                    # Absolute path to the aapt2 to use
ADB                      # Absolute path to the adb to use
AVDMANAGER               # Absolute path to the avdmanager to use
EMULATOR                 # Absolute path to the emulator to use

VAB_EXE                  # Absolute path to a vab executable (Used in tests and sub-cmd execution)
VAB_FLAGS                # Used to pass flags to vab. Command-line flags overwrites any flags/values set via VAB_FLAGS.
VAB_KILL_ADB             # Set to let vab kill adb after use. This is useful on some hosts.

VAB_FLAGS example:

VAB_FLAGS="-v 3 --name 'V App' --api 30 --build-tools 29.0.0" vab /path/to/v/source/file/or/dir

See all options:

vab -h

Setup

vab has support for downloading it's dependencies automatically, except the Java JDK.

If you have nerves to let it try and figure things out automatically simply do: vab install auto

Java

Windows

OpenJDK can be installed via https://adoptium.net/.

macOS

Installing Java JDK using homebrew

brew tap adoptopenjdk/openjdk
brew cask install adoptopenjdk

Linux

You should be able to find a way to install Java JDK >= 8 with your package manager of choice.

sudo apt install openjdk-<version>-jdk

E.g.: sudo apt install openjdk-8-jdk

termux (experimental)

NOTE Currently only tested for arm64 on Android 9 and above.

You must install Java 17 and few more things:

pkg install openjdk-17 aapt apksigner dx ecj

Download, unzip and set enviroment variables to the SDK and NDK from:

https://github.com/Lzhiyong/termux-ndk/releases.

You may have to set the SDK version to be compatible with the NDK (sdkmanager install/uninstall platform-version).

Enjoy using vab on termux!

@MatejMagat305 has made a video of the process you can watch here:

https://www.youtube.com/watch?v=7aUh39w_-2Q.

The accompaning script used in the video can be found here:

https://github.com/MatejMagat305/vab-termux.

Examples

See "Where is the examples folder?" in the FAQ.

Tests

vab, like many other V modules, can be tested with v test ..

Note that vab has runtime tests that requires all runtime dependencies to be installed in order for the tests to run correctly. Runtime tests can be run with vab test-runtime (also part of vab test-all).

Extending vab

The vab command-line tool can be extended with custom user commands. See the "Extending vab" section in the documentation.

Notes

vab targets as low an API level as possible by default for maximum compatibility, you can however tell it to target newer Android versions by using the --api flag. Example: vab --api 30 <...>.

Installed API levels can be listed with vab --list-apis.

Troubleshooting

Android is a complex ecosystem that has differences between build hosts and tool versions - consult our FAQ for answers to frequently asked questions.