Package net.neoforged.neoforge.transfer.energy

Class ItemAccessEnergyHandler

java.lang.Object

net.neoforged.neoforge.transfer.energy.ItemAccessEnergyHandler

All Implemented Interfaces:

EnergyHandler

public class ItemAccessEnergyHandler
extends Object
implements EnergyHandler

A simple implementation of an EnergyHandler backed by an ItemAccess. It can store any level of energy up to a given capacity, and has per-operation insertion and extraction limits. The energy level is stored in an Integer data component.

To use this class, register a new DataComponentType which holds an Integer for your item. Then reference that component from your ICapabilityProvider passed to RegisterCapabilitiesEvent.registerItem(net.neoforged.neoforge.capabilities.ItemCapability<T, C>, net.neoforged.neoforge.capabilities.ICapabilityProvider<net.minecraft.world.item.ItemStack, C, T>, net.minecraft.world.level.ItemLike...) to create an instance of this class.

Field Summary

Fields

Modifier and Type	Field	Description
protected final int	capacity
protected final DataComponentType<Integer>	energyComponent
protected final ItemAccess	itemAccess
protected final int	maxExtract
protected final int	maxInsert
protected final Item	validItem

Constructor Summary

Constructors

Constructor	Description
ItemAccessEnergyHandler(ItemAccess itemAccess, DataComponentType<Integer> energyComponent, int capacity)	Creates a new ItemAccessEnergyHandler instance with 0 stored energy, and no per-operation limit.
ItemAccessEnergyHandler(ItemAccess itemAccess, DataComponentType<Integer> energyComponent, int capacity, int maxTransfer)	Creates a new ItemAccessEnergyHandler instance with 0 stored energy, and the same per-insert and per-extraction limit.
ItemAccessEnergyHandler(ItemAccess itemAccess, DataComponentType<Integer> energyComponent, int capacity, int maxInsert, int maxExtract)	Creates a new ItemAccessEnergyHandler instance.

Method Summary

Modifier and Type	Method	Description
int	extract(int amount, TransactionContext transaction)	Extracts up to the given amount of energy from the handler.
long	getAmountAsLong()	Returns the amount of energy currently stored, as a long.
protected int	getAmountFrom(ItemResource accessResource)	Retrieves the amount stored in the current contents of the item access.
long	getCapacityAsLong()	Returns the capacity of the handler, irrespective of the current amount, as a long.
int	insert(int amount, TransactionContext transaction)	Inserts up to the given amount of energy into the handler.
protected ItemResource	update(ItemResource accessResource, int newAmount)	Returns a resource with updated amount.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.neoforged.neoforge.transfer.energy.EnergyHandler

getAmountAsInt, getCapacityAsInt

Field Details

itemAccess

protected final ItemAccess itemAccess

validItem

protected final Item validItem

energyComponent

protected final DataComponentType<Integer> energyComponent

capacity

protected final int capacity

maxInsert

protected final int maxInsert

maxExtract

protected final int maxExtract

Constructor Details

ItemAccessEnergyHandler

public ItemAccessEnergyHandler(ItemAccess itemAccess,
 DataComponentType<Integer> energyComponent,
 int capacity)

Creates a new ItemAccessEnergyHandler instance with 0 stored energy, and no per-operation limit.

See Also:

• (ItemAccess, DataComponentType, int, int, int)

ItemAccessEnergyHandler

public ItemAccessEnergyHandler(ItemAccess itemAccess,
 DataComponentType<Integer> energyComponent,
 int capacity,
 int maxTransfer)

Creates a new ItemAccessEnergyHandler instance with 0 stored energy, and the same per-insert and per-extraction limit.

See Also:

• (ItemAccess, DataComponentType, int, int, int)

ItemAccessEnergyHandler

public ItemAccessEnergyHandler(ItemAccess itemAccess,
 DataComponentType<Integer> energyComponent,
 int capacity,
 int maxInsert,
 int maxExtract)

Creates a new ItemAccessEnergyHandler instance.

Parameters:

itemAccess - item access backing this handler

energyComponent - type of the data component used to store the energy amount

capacity - maximum capacity of the handler

maxInsert - maximum amount that can be accepted in each call to insert(int, net.neoforged.neoforge.transfer.transaction.TransactionContext)

maxExtract - maximum amount that can be accepted in each call to extract(int, net.neoforged.neoforge.transfer.transaction.TransactionContext)

Throws:

IllegalArgumentException - if any of the int arguments is negative

Method Details

getAmountFrom

protected int getAmountFrom(ItemResource accessResource)

Retrieves the amount stored in the current contents of the item access.

update

protected ItemResource update(ItemResource accessResource,
 int newAmount)

Returns a resource with updated amount.

Parameters:

accessResource - current resource, before the update

newAmount - the new amount

Returns:

accessResource updated with the new amount, or ItemResource.EMPTY if the new amount cannot be stored

getAmountAsLong

public long getAmountAsLong()

Description copied from interface: EnergyHandler

Returns the amount of energy currently stored, as a long.

In general, energy handlers can report long amounts. However, if the handler is known to only support amounts up to Integer.MAX_VALUE, or if the caller prefers to deal in ints only, the int-returning overload can be used instead.

The returned amount must be non-negative.

Specified by:

getAmountAsLong in interface EnergyHandler

Returns:

the amount as a long

See Also:

• EnergyHandler.getAmountAsInt()

getCapacityAsLong

public long getCapacityAsLong()

Description copied from interface: EnergyHandler

Returns the capacity of the handler, irrespective of the current amount, as a long.

In general, energy handlers can report long capacities. However, if the handler is known to only support capacities up to Integer.MAX_VALUE, or if the caller prefers to deal in ints only, the int-returning overload can be used instead.

This function serves as a hint on the maximum amount the energy handler might contain, for example the handler can be considered full if amount >= capacity. Note that the returned capacity may overestimate the actual allowed amount, and it might be smaller than the current amount. The only way to know if a handler will accept a resource, is to try to insert it.

Specified by:

getCapacityAsLong in interface EnergyHandler

Returns:

the capacity, as a long

See Also:

• EnergyHandler.getCapacityAsInt()

insert

public int insert(int amount,
 TransactionContext transaction)

Description copied from interface: EnergyHandler

Inserts up to the given amount of energy into the handler.

Changes to the handler are made in the context of a transaction.

Specified by:

insert in interface EnergyHandler

Parameters:

amount - The maximum amount of energy to insert. Must be non-negative.

transaction - The transaction that this operation is part of.

Returns:

The amount that was inserted. Between 0 (inclusive, nothing was inserted) and amount (inclusive, everything was inserted).

extract

public int extract(int amount,
 TransactionContext transaction)

Description copied from interface: EnergyHandler

Extracts up to the given amount of energy from the handler.

Changes to the handler are made in the context of a transaction.

Specified by:

extract in interface EnergyHandler

Parameters:

amount - The maximum amount of energy to extract. Must be non-negative.

transaction - The transaction that this operation is part of.

Returns:

The amount that was extracted. Between 0 (inclusive, nothing was extracted) and amount (inclusive, everything was extracted).