Compile versions

xbuild/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "xbuild"
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 description = "Builds rust mobile/desktop projects."
 repository = "https://github.com/rust-mobile/xbuild"

xbuild/src/config.rs

@@ -421,6 +421,10 @@ pub struct AndroidDebugConfig {
     pub reverse: HashMap<String, String>,
 }
 
+fn default_java_version() -> usize {
+    8
+}
+
 #[derive(Clone, Debug, Default, Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct AndroidConfig {
@@ -430,6 +434,27 @@ pub struct AndroidConfig {
     pub manifest: AndroidManifest,
     #[serde(default)]
     pub dependencies: Vec<String>,
+    /// Java version used for compilation
+    /// For Java 1.8 and below specify `8` and below
+    #[serde(default = "default_java_version")]
+    pub java_version: usize,
+    /// The gradle plugin version which shall be set in the main build.gradle file
+    /// Make sure it is compatible with the installed gradle version!
+    /// Depending on the plugin version a minimum gradle version must be available
+    /// Depending on the api level a minimum gradle plugin version is required
+    /// https://developer.android.com/build/releases/gradle-plugin?#kts
+    /// 
+    /// Recommendation:
+    /// 1) Select desired api level
+    /// 2) Determine minium gradle plugin version and use at least that version (See url above)
+    /// 3) Determin minium gradle version (See url above)
+    #[serde(default)]
+    pub gradle_plugin_version: Option<String>,
+    /// The kotlin version which shall be set in the main build.gradle file
+    /// Determine version from the gradle plugin version using https://developer.android.com/build/kotlin-support
+    /// Important: This version of Kotlin must be installed on the system!
+    #[serde(default)]
+    pub kotlin_version: Option<String>,
     /// Defaults to [`false`], but uses [`true`] when the user builds a format that requires
     /// `gradle` (i.e. [`Format::Aab`]).
     #[serde(default)]

xbuild/src/gradle/mod.rs

@@ -4,7 +4,6 @@ use apk::Target;
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-static BUILD_GRADLE: &[u8] = include_bytes!("./build.gradle");
 static GRADLE_PROPERTIES: &[u8] = include_bytes!("./gradle.properties");
 static SETTINGS_GRADLE: &[u8] = include_bytes!("./settings.gradle");
 static IC_LAUNCHER: &[u8] = include_bytes!("./ic_launcher.xml");
@@ -40,13 +39,30 @@ pub fn build(env: &BuildEnv, libraries: Vec<(Target, PathBuf)>, out: &Path) -> R
     let kotlin = main.join("kotlin");
     let jnilibs = main.join("jniLibs");
     let res = main.join("res");
+    let config = env.config().android();
+
+    let gradle_plugin_version = config.gradle_plugin_version.as_ref().map(|s| s.as_str()).unwrap_or("7.3.0");
+    let kotlin_version = config.kotlin_version.as_ref().map(|s| s.as_str()).unwrap_or("1.7.20");
+
+    let build_gradle = format!(r#"
+        // Top-level build file where you can add configuration options common to all sub-projects/modules.
+        plugins {{
+            id 'com.android.application' version '{gradle_plugin_version}' apply false
+            id 'com.android.library' version '{gradle_plugin_version}' apply false
+            id 'org.jetbrains.kotlin.android' version '{kotlin_version}' apply false
+        }}
+
+        task clean(type: Delete) {{
+            delete rootProject.buildDir
+        }}
+    "#
+    );
 
     std::fs::create_dir_all(&kotlin)?;
-    std::fs::write(gradle.join("build.gradle"), BUILD_GRADLE)?;
+    std::fs::write(gradle.join("build.gradle"), build_gradle)?;
     std::fs::write(gradle.join("gradle.properties"), GRADLE_PROPERTIES)?;
     std::fs::write(gradle.join("settings.gradle"), SETTINGS_GRADLE)?;
 
-    let config = env.config().android();
     let mut manifest = config.manifest.clone();
 
     let package = manifest.package.take().unwrap_or_default();
@@ -72,6 +88,9 @@ pub fn build(env: &BuildEnv, libraries: Vec<(Target, PathBuf)>, out: &Path) -> R
         r#"assetPacks = [":baseAssets"]"#
     };
 
+    let java_version = config.java_version;
+    let gradle_java_version_rep = if java_version <= 8 { format!("1_{java_version}") } else {format!("{java_version}")};
+
     let app_build_gradle = format!(
         r#"
             plugins {{
@@ -88,6 +107,15 @@ pub fn build(env: &BuildEnv, libraries: Vec<(Target, PathBuf)>, out: &Path) -> R
                     versionCode {version_code}
                     versionName '{version_name}'
                 }}
+
+                compileOptions {{
+                    sourceCompatibility JavaVersion.VERSION_{gradle_java_version_rep}
+                    targetCompatibility JavaVersion.VERSION_{gradle_java_version_rep}
+                }}
+
+                kotlin {{
+                        jvmToolchain({java_version})
+                }}
                 {asset_packs}
             }}
             dependencies {{