Use Fabric's world load event. (#149)

* Use World Load event in fabric api introduced by 0.15.0

* Workaround: Fire overworld load event later

* Add dep on fabric api to patchwork-events-world.

TODO: we should go through and accurately state our fabric api
dependencies for all modules.

Author: kitlith

build.gradle

@@ -56,7 +56,7 @@ allprojects {
 		minecraft "com.mojang:minecraft:$Globals.mcVersion"
 		mappings "net.fabricmc:yarn:${Globals.mcVersion}${Globals.yarnVersion}:v2"
 		modCompile "net.fabricmc:fabric-loader:0.8.4+build.198"
-		modCompile "net.fabricmc.fabric-api:fabric-api:0.4.2+build.246-1.14"
+		modCompile "net.fabricmc.fabric-api:fabric-api:0.15.1+build.260-1.14"
 
 		implementation 'net.patchworkmc:patchwork-eventbus:2.0.1:all'
 		implementation 'com.google.code.findbugs:jsr305:3.0.2'

patchwork-events-world/src/main/java/net/patchworkmc/impl/event/world/WorldEvents.java

@@ -29,9 +29,13 @@
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IWorld;
 import net.minecraft.world.biome.Biome;
+import net.minecraft.world.dimension.DimensionType;
 import net.minecraft.world.level.LevelInfo;
 
-public class WorldEvents {
+import net.fabricmc.api.ModInitializer;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerWorldEvents;
+
+public class WorldEvents implements ModInitializer {
 	public static boolean onCreateWorldSpawn(IWorld world, LevelInfo settings) {
 		return MinecraftForge.EVENT_BUS.post(new WorldEvent.CreateSpawnPosition(world, settings));
 	}
@@ -57,4 +61,15 @@ public static void onWorldUnload(IWorld world) {
 	public static void onWorldSave(IWorld world) {
 		MinecraftForge.EVENT_BUS.post(new WorldEvent.Save(world));
 	}
+
+	@Override
+	public void onInitialize() {
+		ServerWorldEvents.LOAD.register((server, world) -> {
+			// Fabric fires this much earlier than Forge does for the overworld
+			// So, we're going to manually fire it for the overworld.
+			if (world.getDimension().getType() != DimensionType.OVERWORLD) {
+				onWorldLoad(world);
+			}
+		});
+	}
 }

patchwork-events-world/src/main/java/net/patchworkmc/mixin/event/world/MixinMinecraftServer.java

@@ -20,14 +20,15 @@
 package net.patchworkmc.mixin.event.world;
 
 import java.io.IOException;
-import java.util.Iterator;
 import java.util.Map;
 
 import org.spongepowered.asm.mixin.Final;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
 import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
 import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.ServerTask;
@@ -47,42 +48,10 @@ public MixinMinecraftServer(String name) {
 	@Final
 	private Map<DimensionType, ServerWorld> worlds;
 
-	/*
-	// This is a variant of the world load hook that is less likely to break mods and more likely to break on updates.
-	// Should get called once per loop, regardless of which if branch it takes.
-	@Inject(
-		method = "createWorlds",
-		slice = @Slice(
-			from = @At(value = "INVOKE", target = "java/util/Iterator.hasNext ()Z")
-		),
-		at = @At(value = "JUMP", opcode = Opcodes.GOTO),
-		locals = LocalCapture.CAPTURE_FAILHARD
-	)
-	private void hookCreateWorlds(WorldSaveHandler worldSaveHandler, LevelProperties properties, LevelInfo levelInfo, WorldGenerationProgressListener worldGenerationProgressListener, CallbackInfo ci, ServerWorld serverWorld, ServerWorld serverWorld2, Iterator var7, DimensionType dimensionType) {
-		WorldEvents.onWorldLoad(this.worlds.get(dimensionType));
-	}
-
-	*/
-
-	// This injection gets called at the beginning of each loop, and is used to special case the overworld dimension type.
-	@Redirect(method = "createWorlds", at = @At(value = "INVOKE", target = "java/util/Iterator.next ()Ljava/lang/Object;"))
-	private Object proxyNextWorldToSpecialCaseOverworld(Iterator<DimensionType> iterator) {
-		DimensionType type = iterator.next();
-
-		if (type == DimensionType.OVERWORLD) {
-			WorldEvents.onWorldLoad(this.worlds.get(type));
-		}
-
-		return type;
-	}
-
-	// This injection handles every other dimension type.
-	@Redirect(method = "createWorlds", at = @At(value = "INVOKE", target = "java/util/Map.put (Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;", ordinal = 1))
-	private Object proxyPutWorld(Map<Object, Object> worlds, Object type, Object world) {
-		worlds.put(type, world);
-		WorldEvents.onWorldLoad((ServerWorld) world);
-
-		return world;
+	// Fabric usually fires the event much earlier in the method, so this is just picking a point closer to when Forge would fire it.
+	@Inject(method = "createWorlds", at = @At(value = "INVOKE", target = "net/minecraft/world/dimension/DimensionType.getAll ()Ljava/lang/Iterable;"))
+	private void fireLoadForOverworld(CallbackInfo info) {
+		WorldEvents.onWorldLoad(worlds.get(DimensionType.OVERWORLD));
 	}
 
 	@Redirect(method = "shutdown", at = @At(value = "INVOKE", target = "net/minecraft/server/world/ServerWorld.close ()V"))

patchwork-events-world/src/main/resources/fabric.mod.json

@@ -14,6 +14,7 @@
   ],
   "depends": {
     "fabricloader": ">=0.8.4",
+    "fabric": ">=0.15.0",
     "patchwork-fml": "*"
   },
   "mixins": [