Run on Android

Building a Crosswalk Android application with extensions is almost identical to building any other Crosswalk Android application, and uses the same make_apk.py script (see the Run on Android documentation). The main difference is that an additional --extensions option is required, to instruct the script where to find extension directories.

Create the Android packages

To make Android packages for your project, do the following:

Build the extension, as described previously. This will create the xwalk-echo-extension/ directory with the extension files inside.
After the build, the extension project directory (xwalk-echo-extension-src/) will contain a lib/crosswalk-${XWALK-STABLE-ANDROID-X86} directory, which is an unpacked Crosswalk Android distribution. You can use the scripts in here to build the Android packages.

Follow the system setup page to installed the Android SDK. Then use these commands to create the packages:
- Set an environment variable to the location of the project
```
  > PROJECT_DIR=~/<my projects directory>/xwalk-echo-project
```
- Enter the unpacked Crosswalk Android directory
```
  > cd $PROJECT_DIR/xwalk-echo-extension-src/lib/crosswalk-${XWALK-STABLE-ANDROID-X86}
```
- Invoke the package builder
```
  > python make_apk.py --package=org.crosswalkproject.example \
    --enable-remote-debugging --fullscreen \
    --manifest=$PROJECT_DIR/xwalk-echo-app/manifest.json \
    --extensions=$PROJECT_DIR/xwalk-echo-extension-src/xwalk-echo-extension/
```
The generated packages are in the ~/<my projects directory>/xwalk-echo-project/xwalk-echo-extension-src/lib/crosswalk-${XWALK-STABLE-ANDROID-X86} directory, and called xwalk_echo_app_x86.apk and xwalk_echo_app_arm.apk.

Note that if you are using multiple extension directories, you still have a single --extensions option but supply the paths as a comma-delimited string, e.g. --extensions=myextension1,myextension2

Install a package on a target

Choose the correct package for your Android target's architecture and install it with a command like:

$ adb install -r ~/<my projects directory>/xwalk-echo-project/xwalk-echo-extension-src/lib/crosswalk-${XWALK-STABLE-ANDROID-X86}/xwalk_echo_app_x86.apk

This command installs the x86 package. For more details about installing Crosswalk packages on Android, see this page.

The icon for the application should now be in the application menu on the Android target. Tap the icon to start the application and you should see something like this:

Crosswalk Android application with extensions on x86 ZTE Geek

(The screenshot above shows the application running on an x86 ZTE Geek.)

The application should display the text "You said: Hello world", which demonstrates that the Java and JavaScript parts of the Crosswalk extension are communicating correctly.