vcpkg/docs/specifications/prefab.md

Vcpkg: export Android prefab Archives (AAR files)

Note: this is the feature as it was initially specified and does not necessarily reflect the current behavior.

Vcpkg can export android archives (AAR files). Once an archive is created, it can imported in Android Studio as a native dependent. The archive is automatically consumed using android studio's prefab tool.

For more information on Prefab, refer to:

• The official prefab documentation.
• a blog post from Android developers blog: Native Dependencies in Android Studio 4.0

Note for Android Studio users: prefab packages are supported on Android Studio 4+

Requirements

1. ndk <required>

Set environment variable ANDROID_NDK_HOME to your android ndk installation. For example:

export ANDROID_NDK_HOME=/home/your-account/Android/Sdk/ndk-bundle

2. 7zip <required on windows> or zip <required on linux>

3. maven <optional>

4. Android triplets

See android.md for instructions on how to install the triplets.

Please note that in order to use "prefab" (see below), the four architectures are required. If any is missing the export will fail

Example exporting [jsoncpp]

First "vcpkg install" the 4 android architectures (it is mandatory to export all 4 of them)

./vcpkg install jsoncpp:arm-android  jsoncpp:arm64-android  jsoncpp:x64-android  jsoncpp:x86-android

Then, export the prefab:

Note:

• The --prefab-maven flag is optional. Call it if you maven is installed.
• The --prefab-debug flag will output instructions on how to use the prefab archive via gradle.

./vcpkg export --triplet x64-android jsoncpp --prefab --prefab-maven --prefab-debug

You will see an ouput like this:

The following packages are already built and will be exported:
    jsoncpp:arm64-android

Exporting package jsoncpp...
[DEBUG] Found 4 triplets
	arm64-android
	x64-android
	x86-android
	arm-android

...
... Lots of output...
...

[INFO] Scanning for projects...
Downloading from central: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plugin-2.5.pom

...
... Lots of output...
...

[INFO] BUILD SUCCESS
[INFO] Total time:  2.207 s
[INFO] Finished at: 2020-05-10T14:42:28+02:00


...
... Lots of output...
...

[DEBUG] Configuration properties in Android Studio
In app/build.gradle

	com.vcpkg.ndk.support:jsoncpp:1.9.2

And cmake flags

    externalNativeBuild {
                cmake {
                    arguments '-DANDROID_STL=c++_shared'
                    cppFlags "-std=c++17"
                }
            }

In gradle.properties

    android.enablePrefab=true
    android.enableParallelJsonGen=false
    android.prefabVersion=${prefab.version}

Successfuly exported jsoncpp. Checkout .../vcpkg/prefab 

The output directory after export

prefab
└── jsoncpp/
    ├── aar/
    │   ├── AndroidManifest.xml
    │   ├── META-INF/
    │   │   └── LICENSE
    │   └── prefab/
    │       ├── modules/
    │       │   └── jsoncpp/
    │       │       ├── libs/
    │       │       │   ├── android.arm64-v8a/
    │       │       │   │   ├── abi.json
    │       │       │   │   ├── include/
    │       │       │   │   │   └── json/
    │       │       │   │   │       ├── json.h
    │       │       │   │   │       └── ....
    │       │       │   │   └── libjsoncpp.so
    │       │       │   ├── android.armeabi-v7a/
    │       │       │   │   ├── abi.json
    │       │       │   │   ├── include/
    │       │       │   │   │   └── json/
    │       │       │   │   │       ├── json.h
    │       │       │   │   │       └── ....
    │       │       │   │   └── libjsoncpp.so
    │       │       │   ├── android.x86/
    │       │       │   │   ├── abi.json
    │       │       │   │   ├── include/
    │       │       │   │   │   └── json/
    │       │       │   │   │       ├── json.h
    │       │       │   │   │       └── ....
    │       │       │   │   └── libjsoncpp.so
    │       │       │   └── android.x86_64/
    │       │       │       ├── abi.json
    │       │       │       ├── include/
    │       │       │       │   └── json/
    │       │       │   │   │       ├── json.h
    │       │       │   │   │       └── ....
    │       │       │       └── libjsoncpp.so
    │       │       └── module.json
    │       └── prefab.json
    ├── jsoncpp-1.9.2.aar
    └── pom.xml

Example consuming [jsoncpp] via vcpkg and prefab

See the example repo here:

https://github.com/atkawa7/prefab-vpkg-integration-sample