Added death causes.

Author: Olypolyu

src/main/java/turniplabs/halplibe/HalpLibe.java

@@ -9,7 +9,9 @@
 import org.jspecify.annotations.NonNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import turniplabs.halplibe.helper.network.NetworkHandler;
 import turniplabs.halplibe.util.TomlConfigHandler;
+import turniplabs.halplibe.util.deathcause.DeathCauseNetworkMessage;
 import turniplabs.halplibe.util.toml.Toml;
 
 import java.io.File;
@@ -66,6 +68,8 @@ public static String addModId(String modId, String name) {
     @Override
     public void onInitialize() {
         LOGGER.info("HalpLibe initialized.");
+
+        NetworkHandler.registerNetworkMessage(DeathCauseNetworkMessage::new);
     }
 
     @Override

src/main/java/turniplabs/halplibe/mixin/deathcause/MobMixin.java

@@ -0,0 +1,47 @@
+package turniplabs.halplibe.mixin.deathcause;
+
+import com.llamalad7.mixinextras.expression.Definition;
+import com.llamalad7.mixinextras.expression.Expression;
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+
+import net.minecraft.core.Global;
+import net.minecraft.core.entity.Mob;
+import net.minecraft.core.net.command.TextFormatting;
+import net.minecraft.core.world.World;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import turniplabs.halplibe.helper.EnvironmentHelper;
+import turniplabs.halplibe.helper.network.NetworkHandler;
+import turniplabs.halplibe.util.deathcause.DeathCause;
+import turniplabs.halplibe.util.deathcause.DeathCauseMixinInterface;
+import turniplabs.halplibe.util.deathcause.DeathCauseNetworkMessage;
+
+@Mixin(Mob.class)
+public class MobMixin implements DeathCauseMixinInterface {
+
+    @Unique
+    @Nullable DeathCause deathCause = null;
+
+    @Definition(id = "world", field = "Lnet/minecraft/core/entity/Mob;world:Lnet/minecraft/core/world/World;")
+    @Definition(id = "sendGlobalMessageTranslated", method = "Lnet/minecraft/core/world/World;sendGlobalMessageTranslated(Lnet/minecraft/core/net/command/TextFormatting$Base;Ljava/lang/String;[Ljava/lang/String;)V")
+    @Expression("this.world.sendGlobalMessageTranslated(?, ?, ?)")
+    @WrapOperation(method = "onDeath", at = @At("MIXINEXTRAS:EXPRESSION"))
+    public void hijackDeathMessage(World world, TextFormatting.Base format, String key, String[] args, Operation<Void> original) {
+        if (this.deathCause == null) {
+            original.call(world, format, key, args);
+            return;
+        }
+
+        if (!EnvironmentHelper.isClientWorld()) {
+            NetworkHandler.sendToAllPlayers(new DeathCauseNetworkMessage(this.deathCause));
+        }
+    }
+
+    @Override
+    public void halplibe$setDeathCause(DeathCause deathCause) {
+        this.deathCause = deathCause;
+    }
+}

src/main/java/turniplabs/halplibe/util/deathcause/DeathCause.java

@@ -0,0 +1,41 @@
+package turniplabs.halplibe.util.deathcause;
+
+import com.mojang.nbt.tags.CompoundTag;
+import net.minecraft.core.entity.Mob;
+import net.minecraft.core.lang.I18n;
+
+/**
+ * <p><b>This Object represents a cause of death</b>. It is used to set custom death messages for players and entities.</p>
+ *
+ * <h3>The usage is as follows:</h3>
+ * <ol>
+ *
+ * <li>
+ *     You create a custom constructor that acquires all fields from the entity you just attacked.
+ * It is very important that all fields are serializable as they will be sent via the network by NBT.
+ * </li>
+ * <li>Write serialization and deserialization functions for the fields you just defined.</li>
+ *
+ * <li>You write a cute little function to output the translated death message using all fields previously acquired.</li>
+ *
+ * <li>Don't forget to register it to <code>DeathCauseRegistry</code>!</li>
+ *
+ * <li>To display the message: bind it to the victim entity via the <code>DeathCause.bind</code> method. </li>
+ *
+ * <li>Profit!</li>
+ *
+ * </ul>
+ *
+ * <h4>- Kheppo</h4>
+ */
+public abstract class DeathCause {
+    public DeathCause() {};
+
+    public abstract String format(I18n i18n);
+    public abstract void serialize(CompoundTag tag);
+    public abstract void deserialize(CompoundTag tag);
+
+    public void bind(Mob victim) {
+        ((DeathCauseMixinInterface) victim).halplibe$setDeathCause(this);
+    }
+}

src/main/java/turniplabs/halplibe/util/deathcause/DeathCauseMixinInterface.java

@@ -0,0 +1,8 @@
+package turniplabs.halplibe.util.deathcause;
+
+import org.jetbrains.annotations.ApiStatus;
+
+@ApiStatus.Internal
+public interface DeathCauseMixinInterface {
+    void halplibe$setDeathCause(DeathCause deathCause);
+}

src/main/java/turniplabs/halplibe/util/deathcause/DeathCauseNetworkMessage.java

@@ -0,0 +1,54 @@
+package turniplabs.halplibe.util.deathcause;
+
+import com.mojang.nbt.tags.CompoundTag;
+import net.minecraft.core.lang.I18n;
+import org.jspecify.annotations.NonNull;
+import turniplabs.halplibe.helper.network.NetworkMessage;
+import turniplabs.halplibe.helper.network.UniversalPacket;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.Objects;
+
+public class DeathCauseNetworkMessage implements NetworkMessage {
+
+    private CompoundTag deathCauseEncoded;
+    private String deathCauseId;
+
+    public DeathCauseNetworkMessage() {}
+
+    public DeathCauseNetworkMessage(DeathCause deathCause) {
+        this.deathCauseId = DeathCauseRegistry.getInstance().getKey(deathCause.getClass());
+        this.deathCauseEncoded = new CompoundTag();
+        deathCause.serialize(this.deathCauseEncoded);
+    }
+
+    @Override
+    public void encodeToUniversalPacket(@NonNull UniversalPacket packet) {
+        packet.writeString(this.deathCauseId);
+        packet.writeCompoundTag(this.deathCauseEncoded);
+    }
+
+    @Override
+    public void decodeFromUniversalPacket(@NonNull UniversalPacket packet) {
+        this.deathCauseId = packet.readString();
+        this.deathCauseEncoded = packet.readCompoundTag();
+    }
+
+    @Override
+    public void handleClientEnv(NetworkContext context) {
+        final DeathCause deathCause;
+
+        try {
+            deathCause = Objects.requireNonNull(DeathCauseRegistry.getInstance().getItem(this.deathCauseId)).getDeclaredConstructor().newInstance();
+        }
+
+        catch (NoSuchMethodException | InvocationTargetException | InstantiationException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+
+        deathCause.deserialize(this.deathCauseEncoded);
+
+        String deathMessage = deathCause.format(I18n.getInstance());
+        context.player.world.sendGlobalMessage(deathMessage);
+    }
+}

src/main/java/turniplabs/halplibe/util/deathcause/DeathCauseRegistry.java

@@ -0,0 +1,24 @@
+package turniplabs.halplibe.util.deathcause;
+
+import net.minecraft.core.data.registry.Registry;
+import net.minecraft.core.util.HardIllegalArgumentException;
+import net.minecraft.core.util.collection.NamespaceID;
+
+public class DeathCauseRegistry extends Registry<Class<? extends DeathCause>> {
+    private DeathCauseRegistry(){};
+
+    private static final DeathCauseRegistry INSTANCE = new DeathCauseRegistry();
+
+    public static DeathCauseRegistry getInstance() {
+        return INSTANCE;
+    }
+
+    @Override
+    public void register(String key, Class<? extends DeathCause> item) {
+        try { NamespaceID.fromPool(key); }
+        catch (HardIllegalArgumentException e) {
+            throw new RuntimeException("Attempted to define invalid namespaced id for \"%s\"".formatted(item.getCanonicalName()));
+        }
+        super.register(key, item);
+    }
+}

src/main/resources/halplibe.mixins.json

@@ -1,5 +1,8 @@
 {
   "required": true,
+  "mixinextras": {
+    "minVersion": "0.5.0"
+  },
   "minVersion": "0.8",
   "package": "turniplabs.halplibe.mixin",
   "compatibilityLevel": "JAVA_${java}",
@@ -16,6 +19,7 @@
     "accessors.LanguageAccessor",
     "accessors.WeightedRandomBagAccessor",
     "accessors.WeightedRandomBagEntryAccessor",
+    "deathcause.MobMixin",
     "recovery.WorldMixin"
   ],
   "client": [