Initial Kotlin setup and migrate YogaConstants

.gitignore

@@ -73,3 +73,6 @@ local.properties
 
 # Docusarus build
 .docusaurus
+
+# Android Studio
+.idea

build.gradle

@@ -9,6 +9,7 @@ plugins {
     id("com.android.library") version "8.7.1" apply false
     id("com.android.application") version "8.7.1" apply false
     id("io.github.gradle-nexus.publish-plugin") version "1.3.0"
+    id 'org.jetbrains.kotlin.android' version '2.1.20' apply false
 }
 
 allprojects {

java/build.gradle.kts

@@ -9,6 +9,7 @@ plugins {
   id("com.android.library")
   id("maven-publish")
   id("signing")
+  id("org.jetbrains.kotlin.android")
 }
 
 group = "com.facebook.yoga"
@@ -48,6 +49,10 @@ android {
     }
   }
 
+  kotlinOptions {
+    jvmTarget = "1.8"
+  }
+
   publishing {
     multipleVariants {
       withSourcesJar()
@@ -60,6 +65,7 @@ android {
 dependencies {
   implementation("com.google.code.findbugs:jsr305:3.0.2")
   implementation("com.facebook.soloader:soloader:0.10.5")
+  implementation("androidx.core:core-ktx:1.16.0")
   testImplementation("junit:junit:4.12")
 }
 

java/com/facebook/yoga/YogaConstants.kt

@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.yoga
+
+public object YogaConstants {
+  @JvmField public val UNDEFINED: Float = Float.NaN
+
+  @JvmStatic public fun isUndefined(value: Float): Boolean = value.compareTo(UNDEFINED) == 0
+
+  @JvmStatic public fun isUndefined(value: YogaValue): Boolean = value.unit == YogaUnit.UNDEFINED
+
+  @JvmStatic public fun getUndefined(): Float = UNDEFINED
+}