Package net.neoforged.neoforge.event.entity.living

Class FinalizeSpawnEvent

java.lang.Object

net.neoforged.bus.api.Event

net.neoforged.neoforge.event.entity.EntityEvent

net.neoforged.neoforge.event.entity.living.MobSpawnEvent

net.neoforged.neoforge.event.entity.living.FinalizeSpawnEvent

All Implemented Interfaces:

net.neoforged.bus.api.ICancellableEvent

public class FinalizeSpawnEvent
extends MobSpawnEvent
implements net.neoforged.bus.api.ICancellableEvent

This event is fired before Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) is called.
This allows mods to control mob initialization.
In vanilla code, this event is injected by a transformer and not via patch, so calls cannot be traced via call hierarchy (it is not source-visible).

Canceling this event will result in Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) not being called, and the returned value always being null, instead of propagating the SpawnGroupData.
The entity will still be spawned. If you want to prevent the spawn, use setSpawnCancelled(boolean), which will cause Forge to prevent the spawn.

This event is fired on NeoForge.EVENT_BUS, and is only fired on the logical server.

See Also:

• invalid reference

  EventHooks#onFinalizeSpawn

Nested Class Summary

Nested classes/interfaces inherited from class net.neoforged.neoforge.event.entity.living.MobSpawnEvent

MobSpawnEvent.PositionCheck, MobSpawnEvent.SpawnPlacementCheck

Nested classes/interfaces inherited from class net.neoforged.neoforge.event.entity.EntityEvent

EntityEvent.EnteringSection, EntityEvent.EntityConstructing, EntityEvent.Size

Field Summary

Fields

Modifier and Type	Field	Description
private DifficultyInstance	difficulty
private @Nullable SpawnGroupData	spawnData
private final @Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity>	spawner
private final MobSpawnType	spawnType

Constructor Summary

Constructors

Constructor	Description
FinalizeSpawnEvent(Mob entity, ServerLevelAccessor level, double x, double y, double z, DifficultyInstance difficulty, MobSpawnType spawnType, @Nullable SpawnGroupData spawnData, @Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity> spawner)

Method Summary

Modifier and Type	Method	Description
DifficultyInstance	getDifficulty()	Retrieves the DifficultyInstance for the chunk where the mob is about to be spawned.
@Nullable SpawnGroupData	getSpawnData()	Retrieves the SpawnGroupData for this entity.
@Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity>	getSpawner()	Retrieves the underlying BlockEntity or Entity that performed the spawn.
MobSpawnType	getSpawnType()	Retrieves the type of mob spawn that happened (the event that caused the spawn).
boolean	isSpawnCancelled()	Returns the current spawn cancellation status, which can be changed via setSpawnCancelled(boolean).
void	setDifficulty(DifficultyInstance inst)	Sets the difficulty instance for this event, which will be propagated to Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) unless cancelled.
void	setSpawnCancelled(boolean cancel)	This method can be used to cancel the spawn of this mob.
void	setSpawnData(@Nullable SpawnGroupData data)	Sets the spawn data for this entity.

Methods inherited from class net.neoforged.neoforge.event.entity.living.MobSpawnEvent

getEntity, getLevel, getX, getY, getZ

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.neoforged.bus.api.ICancellableEvent

isCanceled, setCanceled

Field Details

spawnType

private final MobSpawnType spawnType

spawner

@Nullable
private final @Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity> spawner

difficulty

private DifficultyInstance difficulty

spawnData

@Nullable
private @Nullable SpawnGroupData spawnData

Constructor Details

FinalizeSpawnEvent

@Internal
public FinalizeSpawnEvent(Mob entity,
 ServerLevelAccessor level,
 double x,
 double y,
 double z,
 DifficultyInstance difficulty,
 MobSpawnType spawnType,
 @Nullable
 @Nullable SpawnGroupData spawnData,
 @Nullable
 @Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity> spawner)

Method Details

getDifficulty

public DifficultyInstance getDifficulty()

Retrieves the DifficultyInstance for the chunk where the mob is about to be spawned.

Returns:

The local difficulty instance

setDifficulty

public void setDifficulty(DifficultyInstance inst)

Sets the difficulty instance for this event, which will be propagated to Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) unless cancelled. The difficulty instance controls how likely certain random effects are to occur, or if certain mob abilities are enabled.

Parameters:

inst - The new difficulty instance.

getSpawnType

public MobSpawnType getSpawnType()

Retrieves the type of mob spawn that happened (the event that caused the spawn). The enum names are self-explanatory.

Returns:

The mob spawn type.

See Also:

• MobSpawnType

getSpawnData

@Nullable
public @Nullable SpawnGroupData getSpawnData()

Retrieves the SpawnGroupData for this entity. When spawning mobs in a loop, this group data is used for the entire group and impacts future spawns. This is how entities like horses ensure that the whole group spawns as a single variant. How this is used varies on a per-entity basis.

Returns:

The spawn group data.

setSpawnData

public void setSpawnData(@Nullable
 @Nullable SpawnGroupData data)

Sets the spawn data for this entity. If this event is cancelled, this value is not used, since Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) will not be called.

Parameters:

data - The new spawn data

See Also:

• getSpawnData()

getSpawner

@Nullable
public @Nullable com.mojang.datafixers.util.Either<BlockEntity,Entity> getSpawner()

Retrieves the underlying BlockEntity or Entity that performed the spawn. This may be a SpawnerBlockEntity, TrialSpawnerBlockEntity, MinecartSpawner, or similar modded object.

This is usually null unless the spawn type is a spawner type, and may still be null even then.

Returns:

The spawner responsible for triggering the spawn, or null if none is available.

setSpawnCancelled

public void setSpawnCancelled(boolean cancel)

This method can be used to cancel the spawn of this mob.

This method must be used if you want to block the spawn, as canceling the event only blocks the call to Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData).

Note that if the spawn is cancelled, but the event is not, then Mob.finalizeSpawn(net.minecraft.world.level.ServerLevelAccessor, net.minecraft.world.DifficultyInstance, net.minecraft.world.entity.MobSpawnType, net.minecraft.world.entity.SpawnGroupData) will still be called, but the entity will not be spawned. Usually that has no side effects, but callers should be aware.

Parameters:

cancel - If the spawn should be cancelled (or not).

isSpawnCancelled

public boolean isSpawnCancelled()

Returns the current spawn cancellation status, which can be changed via setSpawnCancelled(boolean).

Returns:

If this mob's spawn is cancelled or not.