Setup logic to publish the Godot Android library to MavenCentral

platform/android/java/app/config.gradle

@@ -4,7 +4,7 @@ ext.versions = [
     minSdk             : 19, // Also update 'platform/android/java/lib/AndroidManifest.xml#minSdkVersion' & 'platform/android/export/export_plugin.cpp#DEFAULT_MIN_SDK_VERSION'
     targetSdk          : 30, // Also update 'platform/android/java/lib/AndroidManifest.xml#targetSdkVersion' & 'platform/android/export/export_plugin.cpp#DEFAULT_TARGET_SDK_VERSION'
     buildTools         : '30.0.3',
-    kotlinVersion      : '1.5.10',
+    kotlinVersion      : '1.6.10',
     fragmentVersion    : '1.3.6',
     javaVersion        : 11,
     ndkVersion         : '21.4.7075529' // Also update 'platform/android/detect.py#get_project_ndk_version()' when this is updated.
@@ -86,13 +86,12 @@ ext.getGodotEditorVersion = { ->
     return editorVersion
 }
 
-ext.getGodotLibraryVersion = { ->
+ext.generateGodotLibraryVersion = { List<String> requiredKeys ->
     // Attempt to read the version from the `version.py` file.
     String libraryVersion = ""
 
     File versionFile = new File("../../../version.py")
     if (versionFile.isFile()) {
-        List<String> requiredKeys = ["major", "minor", "patch", "status", "module_config"]
         def map = [:]
 
         List<String> lines = versionFile.readLines()
@@ -121,6 +120,16 @@ ext.getGodotLibraryVersion = { ->
     return libraryVersion
 }
 
+ext.getGodotLibraryVersion = { ->
+    List<String> requiredKeys = ["major", "minor", "patch", "status", "module_config"]
+    return generateGodotLibraryVersion(requiredKeys)
+}
+
+ext.getGodotPublishVersion = { ->
+    List<String> requiredKeys = ["major", "minor", "patch", "status"]
+    return generateGodotLibraryVersion(requiredKeys)
+}
+
 final String VALUE_SEPARATOR_REGEX = "\\|"
 
 // get the list of ABIs the project should be exported to

platform/android/java/build.gradle

@@ -1,15 +1,19 @@
+apply plugin: 'io.github.gradle-nexus.publish-plugin'
 apply from: 'app/config.gradle'
+apply from: 'scripts/publish-root.gradle'
 
 buildscript {
     apply from: 'app/config.gradle'
 
     repositories {
         google()
         mavenCentral()
+        maven { url "https://plugins.gradle.org/m2/" }
     }
     dependencies {
         classpath libraries.androidGradlePlugin
         classpath libraries.kotlinGradlePlugin
+        classpath 'io.github.gradle-nexus:publish-plugin:1.1.0'
     }
 }
 

platform/android/java/lib/build.gradle

@@ -1,6 +1,13 @@
 apply plugin: 'com.android.library'
 apply plugin: 'kotlin-android'
 
+ext {
+    PUBLISH_VERSION = getGodotPublishVersion()
+    PUBLISH_ARTIFACT_ID = 'godot'
+}
+
+apply from: "../scripts/publish-module.gradle"
+
 dependencies {
     implementation libraries.kotlinStdLib
     implementation libraries.androidxFragment
@@ -21,6 +28,8 @@ android {
         manifestPlaceholders = [godotLibraryVersion: getGodotLibraryVersion()]
     }
 
+    namespace = "org.godotengine.godot"
+
     compileOptions {
         sourceCompatibility versions.javaVersion
         targetCompatibility versions.javaVersion
@@ -111,4 +120,12 @@ android {
         // Schedule the tasks so the generated libs are present before the aar file is packaged.
         tasks["merge${buildType}JniLibFolders"].dependsOn taskName
     }
+
+    // TODO: Enable when issues with AGP 7.1+ are resolved (https://github.com/GodotVR/godot_openxr/issues/187).
+//    publishing {
+//        singleVariant("release") {
+//            withSourcesJar()
+//            withJavadocJar()
+//        }
+//    }
 }

platform/android/java/scripts/publish-module.gradle

@@ -0,0 +1,74 @@
+apply plugin: 'maven-publish'
+apply plugin: 'signing'
+
+group = ossrhGroupId
+version = PUBLISH_VERSION
+
+afterEvaluate {
+    publishing {
+        publications {
+            release(MavenPublication) {
+                // The coordinates of the library, being set from variables that
+                // we'll set up later
+                groupId ossrhGroupId
+                artifactId PUBLISH_ARTIFACT_ID
+                version PUBLISH_VERSION
+
+                // Two artifacts, the `aar` (or `jar`) and the sources
+                if (project.plugins.findPlugin("com.android.library")) {
+                    from components.release
+                } else {
+                    from components.java
+                }
+
+                // Mostly self-explanatory metadata
+                pom {
+                    name = PUBLISH_ARTIFACT_ID
+                    description = 'Godot Engine Android Library'
+                    url = 'https://godotengine.org/'
+                    licenses {
+                        license {
+                            name = 'MIT License'
+                            url = 'https://github.com/godotengine/godot/blob/master/LICENSE.txt'
+                        }
+                    }
+                    developers {
+                        developer {
+                            id = 'm4gr3d'
+                            name = 'Fredia Huya-Kouadio'
+                            email = 'fhuyakou@gmail.com'
+                        }
+                        developer {
+                            id = 'reduz'
+                            name = 'Juan Linietsky'
+                            email = 'reduzio@gmail.com'
+                        }
+                        developer {
+                            id = 'akien-mga'
+                            name = 'Rémi Verschelde'
+                            email = 'rverschelde@gmail.com'
+                        }
+                        // Add all other devs here...
+                    }
+
+                    // Version control info - if you're using GitHub, follow the
+                    // format as seen here
+                    scm {
+                        connection = 'scm:git:github.com/godotengine/godot.git'
+                        developerConnection = 'scm:git:ssh://github.com/godotengine/godot.git'
+                        url = 'https://github.com/godotengine/godot/tree/master'
+                    }
+                }
+            }
+        }
+    }
+}
+
+signing {
+    useInMemoryPgpKeys(
+        rootProject.ext["signing.keyId"],
+        rootProject.ext["signing.key"],
+        rootProject.ext["signing.password"],
+    )
+    sign publishing.publications
+}

platform/android/java/scripts/publish-root.gradle

@@ -0,0 +1,39 @@
+// Create variables with empty default values
+ext["signing.keyId"] = ''
+ext["signing.password"] = ''
+ext["signing.key"] = ''
+ext["ossrhGroupId"] = ''
+ext["ossrhUsername"] = ''
+ext["ossrhPassword"] = ''
+ext["sonatypeStagingProfileId"] = ''
+
+File secretPropsFile = project.rootProject.file('local.properties')
+if (secretPropsFile.exists()) {
+    // Read local.properties file first if it exists
+    Properties p = new Properties()
+    new FileInputStream(secretPropsFile).withCloseable { is -> p.load(is) }
+    p.each { name, value -> ext[name] = value }
+} else {
+    // Use system environment variables
+    ext["ossrhGroupId"] = System.getenv('OSSRH_GROUP_ID')
+    ext["ossrhUsername"] = System.getenv('OSSRH_USERNAME')
+    ext["ossrhPassword"] = System.getenv('OSSRH_PASSWORD')
+    ext["sonatypeStagingProfileId"] = System.getenv('SONATYPE_STAGING_PROFILE_ID')
+    ext["signing.keyId"] = System.getenv('SIGNING_KEY_ID')
+    ext["signing.password"] = System.getenv('SIGNING_PASSWORD')
+    ext["signing.key"] = System.getenv('SIGNING_KEY')
+}
+
+// Set up Sonatype repository
+nexusPublishing {
+    repositories {
+        sonatype {
+            stagingProfileId = sonatypeStagingProfileId
+            username = ossrhUsername
+            password = ossrhPassword
+            nexusUrl.set(uri("https://s01.oss.sonatype.org/service/local/"))
+            snapshotRepositoryUrl.set(uri("https://s01.oss.sonatype.org/content/repositories/snapshots/"))
+        }
+    }
+}
+