first Kotlin version

src/main/kotlin/mods/betterfoliage/client/gui/BiomeListConfigEntry.kt

@@ -0,0 +1,19 @@
+package mods.betterfoliage.client.gui
+
+import cpw.mods.fml.client.config.GuiConfig
+import cpw.mods.fml.client.config.GuiConfigEntries
+import cpw.mods.fml.client.config.IConfigElement
+import mods.octarinecore.client.gui.IdListConfigEntry
+import net.minecraft.world.biome.BiomeGenBase
+
+/** Toggleable list of all defined biomes. */
+class BiomeListConfigEntry(
+        owningScreen: GuiConfig,
+        owningEntryList: GuiConfigEntries,
+        configElement: IConfigElement<*>)
+: IdListConfigEntry<BiomeGenBase>(owningScreen, owningEntryList, configElement) {
+
+    override val baseSet: List<BiomeGenBase> get() = BiomeGenBase.getBiomeGenArray().filterNotNull()
+    override val BiomeGenBase.itemId: Int get() = this.biomeID
+    override val BiomeGenBase.itemName: String get() = this.biomeName
+}

src/main/kotlin/mods/betterfoliage/client/gui/ConfigGuiFactory.kt

@@ -0,0 +1,27 @@
+package mods.betterfoliage.client.gui
+
+import cpw.mods.fml.client.IModGuiFactory
+import cpw.mods.fml.client.IModGuiFactory.RuntimeOptionCategoryElement
+import cpw.mods.fml.client.config.GuiConfig
+import mods.betterfoliage.BetterFoliageMod
+import mods.betterfoliage.client.config.Config
+import net.minecraft.client.Minecraft
+import net.minecraft.client.gui.GuiScreen
+
+class ConfigGuiFactory : IModGuiFactory {
+
+    override fun mainConfigGuiClass() = ConfigGuiBetterFoliage::class.java
+    override fun runtimeGuiCategories() = hashSetOf<RuntimeOptionCategoryElement>()
+    override fun getHandlerFor(element: RuntimeOptionCategoryElement?) = null
+    override fun initialize(minecraftInstance: Minecraft?) { }
+
+    class ConfigGuiBetterFoliage(parentScreen: GuiScreen?) : GuiConfig(
+            parentScreen,
+            Config.rootGuiElements,
+            BetterFoliageMod.MOD_ID,
+            null,
+            false,
+            false,
+            BetterFoliageMod.MOD_NAME
+    )
+}