How to build for Android

Install tools

Get and install the Java Development Kit
Download the Android Studio/SDK command line tools (scroll to the bottom to find packages with only the command line tools).
Unpack the command line tools, e.g. into $HOME/cmdline-tools/latest

Add the cmdline-tools's parent folder to the environment variable ANDROID_HOME, and the /bin-folder to PATH:

# in .bashrc or similar
export ANDROID_HOME="$HOME/.android"
export PATH="$ANDROID_HOME/cmdline-tools/latest/bin:$PATH"

Check for updates:
```
sdkmanager --update
```

Install build tools:

sdkmanager --install "build-tools;34.0.0"

Build for Android

Clone the repo as described in Get started
Navigate to seedlingo/app
Run the build command
```
npm run build:android
```
Find the final .apk-file in android/app/build/outputs/apk/release/.

Troubleshooting

Must have Java JDK installed

Check with:

javac --version

Install with:

 sudo apt install openjdk-21-jdk-headless

Java and gradle versions must sync

Verify that gradle version is in sync with java version (see the Gradle Compatibility Matrix).

Update seedlingo/app/android/gradle/wrapper/gradle-wrapper.properties accordingly, e.g. set distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-all.zip for javac --version -> 21.0.4:

# at [...]/seedlingo/app/android
./gradlew wrapper --gradle-version 8.9
# if successful, repeat
./gradlew wrapper --gradle-version 8.9

Running the command twice ensures that the updated version is working correctly on the second run.

Warning

The version of the Android Gradle plugin (AGP) and Gradle itself are not the same version number. Check compatibility at Android Gradle Plugin > Update Gradle

Optional extras

Sign the .apk bundle

Add an apksign.keystore file (see the Android Studio documentation) to ~/.android and run the build command npm run build:android again.

Splash and icons

Update splash image and icons

npx cordova-res android --skip-config --copy --icon-source public/logo-m/apple-touch-icon-512x512.png --splash-source public/logo/splash.png --icon-foreground-source public/logo/icon-foreground.png --icon-background-source public/logo/icon-background.png`

Edit ic_launcher.xml and ic_launcher_round.xml, swap background's @color to @mipmap