build.gradle

/*
 * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
 */

import org.gradle.api.artifacts.transform.*

import java.nio.file.Files
import java.util.zip.ZipEntry
import java.util.zip.ZipFile

ext.tasks_version = '16.0.1'

def artifactType = Attribute.of("artifactType", String)
def unpackedAar = Attribute.of("unpackedAar", Boolean)

configurations.all {
    afterEvaluate {
        if (canBeResolved) {
            attributes.attribute(unpackedAar, true) // request all AARs to be unpacked
        }
    }
}

dependencies {
    attributesSchema {
        attribute(unpackedAar)
    }

    artifactTypes {
        aar {
            attributes.attribute(unpackedAar, false)
        }
    }

    registerTransform(UnpackAar) {
        from.attribute(unpackedAar, false).attribute(artifactType, "aar")
        to.attribute(unpackedAar, true).attribute(artifactType, "jar")
    }

    api("com.google.android.gms:play-services-tasks:$tasks_version") {
        exclude group: 'com.android.support'
    }
}

tasks.withType(dokka.getClass()) {
    externalDocumentationLink {
        url = new URL("https://developers.google.com/android/reference/")
        // This is workaround for missing package list in Google API
        packageListUrl = projectDir.toPath().resolve("package.list").toUri().toURL()
    }
}

abstract class UnpackAar implements TransformAction<TransformParameters.None> {
    @InputArtifact
    abstract Provider<FileSystemLocation> getInputArtifact()

    @Override
    void transform(TransformOutputs outputs) {
        ZipFile zip = new ZipFile(inputArtifact.get().asFile)
        try {
            for (entry in zip.entries()) {
                if (!entry.isDirectory() && entry.name.endsWith(".jar")) {
                    unzipEntryTo(zip, entry, outputs.file(entry.name))
                }
            }
        } finally {
            zip.close()
        }
    }

    private static void unzipEntryTo(ZipFile zip, ZipEntry entry, File output) {
        InputStream stream = zip.getInputStream(entry)
        try {
            Files.copy(stream, output.toPath())
        } finally {
            stream.close()
        }
    }
}