Simple native method.

skiko/build.gradle.kts

@@ -6,7 +6,8 @@ plugins {
 group = "org.jetbrains.skiko"
 version = "0.1-SNAPSHOT"
 
-val skiaDir = System.getenv("SKIA_DIR") ?: throw Error("Set SKIA_DIR env variable!")
+
+val skiaDir = System.getenv("SKIA_DIR") ?: "/Users/igotti/compose/skija/third_party/skia"
 val hostOs = System.getProperty("os.name")
 val target =  when {
     hostOs == "Mac OS X" -> "macos"
@@ -146,6 +147,13 @@ val skikoArtifact = artifacts.add("archives", file(skikoJarFile)) {
     builtBy("skikoJar")
 }
 
+project.tasks.register<JavaExec>("run") {
+    dependsOn("skikoJar")
+    main = "org.jetbrains.skiko.MainKt"
+    classpath = files(skikoJarFile)
+}
+
+
 publishing {
     publications {
         create<MavenPublication>("skiko") {

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/Main.kt

+package org.jetbrains.skiko
+
+fun main() {
+    println(SkiaWindow().nativeMethod(41))
+}
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skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkiaWindow.kt

+package org.jetbrains.skiko
+
+import org.jetbrains.skija.Library
+
+class SkiaWindow {
+  companion object {
+    init {
+      Library.load("/", "skiko")
+    }
+  }
+
+  external fun nativeMethod(param: Long): Long
+}
+

skiko/src/main/cpp/Window.cc

+#include <jni.h>
+
+extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_SkiaWindow_nativeMethod
+  (JNIEnv* env, jobject thiz, jlong param) {
+  return param + 1;
+}
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