MixinEntity.java

/*
 * This file is part of Sponge, licensed under the MIT License (MIT).
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 * Copyright (c) SpongePowered <https://www.spongepowered.org>
 * Copyright (c) contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
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 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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 * furnished to do so, subject to the following conditions:
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 * The above copyright notice and this permission notice shall be included in
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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package org.spongepowered.server.mixin.core.entity;

import net.minecraft.entity.Entity;
import net.minecraft.nbt.NBTTagCompound;
import net.minecraft.world.World;
import org.spongepowered.api.event.SpongeEventFactory;
import org.spongepowered.api.event.cause.Cause;
import org.spongepowered.api.event.cause.NamedCause;
import org.spongepowered.asm.mixin.Mixin;
import org.spongepowered.asm.mixin.injection.At;
import org.spongepowered.asm.mixin.injection.Inject;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
import org.spongepowered.common.SpongeImpl;
import org.spongepowered.common.data.util.NbtDataUtil;
import org.spongepowered.common.interfaces.entity.IMixinEntity;

import javax.annotation.Nullable;

@Mixin(Entity.class)
public abstract class MixinEntity implements IMixinEntity {

    @Nullable private NBTTagCompound customEntityData;

    @Inject(method = "<init>(Lnet/minecraft/world/World;)V", at = @At("RETURN"), remap = false)
    private void onConstructed(World world, CallbackInfo ci) {
        SpongeImpl.postEvent(SpongeEventFactory.createConstructEntityEventPost(Cause.of(NamedCause.source(world)),
                this, this.getType(), this.getTransform()));
    }

    @Override
    public final NBTTagCompound getEntityData() {
        if (this.customEntityData == null) {
            this.customEntityData = new NBTTagCompound();
        }
        return this.customEntityData;
    }

    @Inject(method = "readFromNBT(Lnet/minecraft/nbt/NBTTagCompound;)V",
            at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/Entity;readEntityFromNBT(Lnet/minecraft/nbt/NBTTagCompound;)V"))
    private void preReadFromNBTInject(NBTTagCompound tagCompound, CallbackInfo ci) {
        if (tagCompound.hasKey(NbtDataUtil.FORGE_DATA)) {
            this.customEntityData = tagCompound.getCompoundTag(NbtDataUtil.FORGE_DATA);
        }
    }

    @Inject(method = "writeToNBT(Lnet/minecraft/nbt/NBTTagCompound;)Lnet/minecraft/nbt/NBTTagCompound;",
            at = @At(value = "INVOKE", target = "Lnet/minecraft/entity/Entity;writeEntityToNBT(Lnet/minecraft/nbt/NBTTagCompound;)V"))
    private void preWriteToNBTInject(NBTTagCompound tagCompound, CallbackInfoReturnable<NBTTagCompound> ci) {
        if (this.customEntityData != null) {
            tagCompound.setTag(NbtDataUtil.FORGE_DATA, this.customEntityData);
        }
    }

}