Experimental shulker stacking sync

build.gradle

@@ -31,8 +31,8 @@ dependencies {
 	mappings "net.fabricmc:yarn:${project.yarn_mappings}:v2"
 	modImplementation "net.fabricmc:fabric-loader:${project.loader_version}"
 
-	modRuntimeOnly modCompileOnly ("maven.modrinth:lithium:${project.lithium}")
-	modRuntimeOnly "curse.maven:carpet-349239:${project.carpet}"
+	modCompileOnly ("maven.modrinth:lithium:${project.lithium}")
+	modImplementation "curse.maven:carpet-349239:${project.carpet}"
 }
 
 processResources {

gradle.properties

@@ -6,10 +6,10 @@ org.gradle.parallel=true
 # check these on https://fabricmc.net/develop
 minecraft_version=1.21
 yarn_mappings=1.21+build.2
-loader_version=0.15.11
+loader_version=0.16.2
 
 # Mod Properties
-mod_version=1.3
+mod_version=1.4
 maven_group=dev.kikugie
 archives_base_name=shulkerfix
 

src/main/java/dev/kikugie/shulkerfix/ShulkerFixMod.java

@@ -0,0 +1,16 @@
+package dev.kikugie.shulkerfix;
+
+import dev.kikugie.shulkerfix.carpet.ShulkerFixExtension;
+import net.fabricmc.api.ModInitializer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ShulkerFixMod implements ModInitializer {
+	public static final Logger LOGGER = LoggerFactory.getLogger(ShulkerFixMod.class);
+	public static final String MOD_ID = "shulkerfix";
+
+	@Override
+	public void onInitialize() {
+		ShulkerFixExtension.init();
+	}
+}

src/main/java/dev/kikugie/shulkerfix/Util.java

@@ -1,11 +1,18 @@
 package dev.kikugie.shulkerfix;
 
 import net.minecraft.block.ShulkerBoxBlock;
+import net.minecraft.component.DataComponentTypes;
 import net.minecraft.item.BlockItem;
 import net.minecraft.item.ItemStack;
 
 public class Util {
 	public static boolean isShulkerBox(ItemStack stack) {
 		return stack.getItem() instanceof BlockItem blockItem && blockItem.getBlock() instanceof ShulkerBoxBlock;
 	}
+
+	public static boolean hasCustomMaxStackSize(ItemStack stack) {
+		int defaultStackSize = stack.getDefaultComponents().getOrDefault(DataComponentTypes.MAX_STACK_SIZE, 1);
+		int currentStackSize = stack.getOrDefault(DataComponentTypes.MAX_STACK_SIZE, 1);
+		return defaultStackSize != currentStackSize;
+	}
 }

src/main/java/dev/kikugie/shulkerfix/carpet/ShulkerFixExtension.java

@@ -0,0 +1,48 @@
+package dev.kikugie.shulkerfix.carpet;
+
+import carpet.CarpetExtension;
+import carpet.CarpetServer;
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+import dev.kikugie.shulkerfix.ShulkerFixMod;
+import net.fabricmc.loader.api.FabricLoader;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.util.Collections;
+import java.util.Map;
+
+public class ShulkerFixExtension implements CarpetExtension {
+	public static final ShulkerFixExtension INSTANCE = new ShulkerFixExtension();
+
+	public static void init() {
+		CarpetServer.manageExtension(INSTANCE);
+	}
+
+	@Override
+	public String version() {
+		var container = FabricLoader.getInstance().getModContainer(ShulkerFixMod.MOD_ID);
+		return container.isPresent() ? container.get().getMetadata().getVersion().getFriendlyString() : "undefined";
+	}
+
+	@Override
+	public void onGameStarted() {
+		CarpetServer.settingsManager.parseSettingsClass(ShulkerFixSettings.class);
+	}
+
+	@Override
+	public Map<String, String> canHasTranslations(String lang) {
+		try (InputStream stream = ShulkerFixSettings.class.getClassLoader().getResourceAsStream("assets/shulkerfix/lang/%s.json".formatted(lang))) {
+			if (stream == null) return Collections.emptyMap();
+			Gson gson = new Gson();
+			TypeToken<Map<String, String>> token = new TypeToken<>() {};
+			Reader reader = new InputStreamReader(stream);
+			return gson.fromJson(reader, token.getType());
+		} catch (IOException e) {
+			ShulkerFixMod.LOGGER.error("Failed to decode mod language file %s.json".formatted(lang), e);
+			return Collections.emptyMap();
+		}
+	}
+}

src/main/java/dev/kikugie/shulkerfix/carpet/ShulkerFixSettings.java

@@ -0,0 +1,11 @@
+package dev.kikugie.shulkerfix.carpet;
+
+import carpet.api.settings.Rule;
+import carpet.api.settings.RuleCategory;
+
+public class ShulkerFixSettings {
+	public static final String SHULKERFIX = "shulkerfix";
+
+	@Rule(categories = {SHULKERFIX, RuleCategory.BUGFIX, RuleCategory.EXPERIMENTAL})
+	public static boolean clientShulkerSync = false;
+}

src/main/java/dev/kikugie/shulkerfix/mixin/ItemStackCodecMixin.java

@@ -0,0 +1,49 @@
+package dev.kikugie.shulkerfix.mixin;
+
+import com.llamalad7.mixinextras.injector.ModifyReturnValue;
+import dev.kikugie.shulkerfix.Util;
+import dev.kikugie.shulkerfix.carpet.ShulkerFixSettings;
+import net.minecraft.component.DataComponentTypes;
+import net.minecraft.component.type.NbtComponent;
+import net.minecraft.item.ItemStack;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Pseudo;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
+
+/**
+ * Implementation from the <a href="https://github.com/ch-yx/fabric-carpet/blob/18d4f8fdc02069fb4d41cd28d703f8d7a6aa7579/src/main/java/carpet/mixins/ItemStack_stackableShulkerBoxesEncodeMixin.java">ch-yx fork</a>.
+ */
+@Pseudo
+@Mixin(targets = "net.minecraft.item.ItemStack$1")
+public class ItemStackCodecMixin {
+	@Unique
+	private static final String MARKER = "__carpet_data!!the_max_stack_size_tag_is_fake!__";
+
+	@ModifyVariable(method = "encode(Lnet/minecraft/network/RegistryByteBuf;Lnet/minecraft/item/ItemStack;)V", at = @At("HEAD"), argsOnly = true)
+	private ItemStack setModifiedStackSize(ItemStack stack) {
+		if (ShulkerFixSettings.clientShulkerSync &&
+			stack.getOrDefault(DataComponentTypes.MAX_STACK_SIZE, 1) < stack.getCount() &&
+			!stack.getOrDefault(DataComponentTypes.CUSTOM_DATA, NbtComponent.DEFAULT).contains(MARKER) &&
+			!Util.hasCustomMaxStackSize(stack)
+		) {
+			stack = stack.copy();
+			stack.set(DataComponentTypes.MAX_STACK_SIZE, stack.getMaxCount());
+			NbtComponent.set(DataComponentTypes.CUSTOM_DATA, stack, nbt -> nbt.putBoolean(MARKER, true));
+		}
+		return stack;
+	}
+
+	@ModifyReturnValue(method = "decode(Lnet/minecraft/network/RegistryByteBuf;)Lnet/minecraft/item/ItemStack;", at = @At("RETURN"))
+	private ItemStack getModifiedStackSize(ItemStack stack) {
+		// We still do decoding, in case the rule was disabled
+		if (stack.getOrDefault(DataComponentTypes.CUSTOM_DATA, NbtComponent.DEFAULT).contains(MARKER)) {
+			stack = stack.copy();
+			stack.set(DataComponentTypes.MAX_STACK_SIZE, stack.getDefaultComponents().get(DataComponentTypes.MAX_STACK_SIZE));
+			stack.capCount(stack.getMaxCount());
+			NbtComponent.set(DataComponentTypes.CUSTOM_DATA, stack, nbt -> nbt.remove(MARKER));
+		}
+		return stack;
+	}
+}

src/main/resources/assets/shulkerfix/lang/en_us.json

@@ -0,0 +1,5 @@
+{
+  "carpet.category.shulkerfix": "ShulkerFix",
+  "carpet.rule.clientShulkerSync.name": "Sync Stacked Shulker Count",
+  "carpet.rule.clientShulkerSync.desc": "Fixes displayed shulker amount on vanilla clients. See issue #1899 in Carpet's repo."
+}

src/main/resources/fabric.mod.json

@@ -1,24 +1,30 @@
 {
-	"schemaVersion": 1,
-	"id": "shulkerfix",
-	"version": "${version}",
-	"name": "Stackable Shulker Fix",
-	"description": "Makes stackable shulker boxes unstackable by hoppers",
-	"authors": [
-		"KikuGIe"
-	],
-	"license": "MIT",
-	"environment": "*",
-	"mixins": [
-		"shulkerfix.mixins.json"
-	],
-	"depends": {
-		"fabricloader": ">=0.15",
-		"minecraft": ">=1.20.5",
-		"carpet": ">=1.4.140",
-		"java": ">=21"
-	},
-	"recommends": {
-		"lithium": ">=0.12"
-	}
+  "schemaVersion": 1,
+  "id": "shulkerfix",
+  "version": "${version}",
+  "name": "Stackable Shulker Fix",
+  "description": "Makes stackable shulker boxes unstackable by hoppers",
+  "authors": [
+    "KikuGIe"
+  ],
+  "license": "MIT",
+  "environment": "*",
+  "mixins": [
+    "shulkerfix.mixins.json",
+    "shulkerfix-compat.mixins.json"
+  ],
+  "entrypoints": {
+    "main": [
+      "dev.kikugie.shulkerfix.ShulkerFixMod"
+    ]
+  },
+  "depends": {
+    "fabricloader": ">=0.15",
+    "minecraft": ">=1.20.5",
+    "carpet": ">=1.4.140",
+    "java": ">=21"
+  },
+  "recommends": {
+    "lithium": ">=0.12"
+  }
 }

src/main/resources/shulkerfix-compat.mixins.json

@@ -0,0 +1,10 @@
+{
+  "required": true,
+  "package": "dev.kikugie.shulkerfix.mixin",
+  "compatibilityLevel": "JAVA_21",
+  "mixins": [
+    "ItemStackCodecMixin",
+    "LithiumHopperHelperMixin",
+    "LithiumStackListMixin"
+  ]
+}

src/main/resources/shulkerfix.mixins.json

@@ -4,8 +4,6 @@
   "compatibilityLevel": "JAVA_21",
   "mixins": [
     "HopperBlockEntityMixin",
-    "LithiumHopperHelperMixin",
-    "LithiumStackListMixin",
     "ScreenHandlerMixin"
   ],
   "injectors": {