ForgePatch/common/net/minecraftforge/fluids/ItemFluidContainer.java

package net.minecraftforge.fluids;

import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;

/**
 * Reference implementation of {@link IFluidContainerItem}. Use/extend this or implement your own.
 * 
 * @author King Lemming
 * 
 */
public class ItemFluidContainer extends Item implements IFluidContainerItem {

    protected int capacity;

    public ItemFluidContainer(int itemID) {

        super(itemID);
    }

    public ItemFluidContainer(int itemID, int capacity) {

        super(itemID);
        this.capacity = capacity;
    }

    public ItemFluidContainer setCapacity(int capacity) {

        this.capacity = capacity;
        return this;
    }

    /* IFluidContainerItem */
    @Override
    public FluidStack getFluid(ItemStack container) {

        if (container.stackTagCompound == null || !container.stackTagCompound.hasKey("Fluid")) {
            return null;
        }
        return FluidStack.loadFluidStackFromNBT(container.stackTagCompound.getCompoundTag("Fluid"));
    }

    @Override
    public int getCapacity(ItemStack container) {

        return capacity;
    }

    @Override
    public int fill(ItemStack container, FluidStack resource, boolean doFill) {

        if (resource == null) {
            return 0;
        }
        if (!doFill) {
            if (container.stackTagCompound == null || !container.stackTagCompound.hasKey("Fluid")) {
                return Math.min(capacity, resource.amount);
            }
            FluidStack stack = FluidStack.loadFluidStackFromNBT(container.stackTagCompound.getCompoundTag("Fluid"));

            if (stack == null) {
                return Math.min(capacity, resource.amount);
            }
            if (!stack.isFluidEqual(resource)) {
                return 0;
            }
            return Math.min(capacity - stack.amount, resource.amount);
        }
        if (container.stackTagCompound == null) {
            container.stackTagCompound = new NBTTagCompound();
        }
        if (!container.stackTagCompound.hasKey("Fluid")) {
            NBTTagCompound fluidTag = resource.writeToNBT(new NBTTagCompound());

            if (capacity < resource.amount) {
                fluidTag.setInteger("Amount", capacity);
                container.stackTagCompound.setTag("Fluid", fluidTag);
                return capacity;
            }
            container.stackTagCompound.setTag("Fluid", fluidTag);
            return resource.amount;
        }
        NBTTagCompound fluidTag = container.stackTagCompound.getCompoundTag("Fluid");
        FluidStack stack = FluidStack.loadFluidStackFromNBT(fluidTag);

        if (!stack.isFluidEqual(resource)) {
            return 0;
        }
        int filled = capacity - resource.amount;

        if (resource.amount < filled) {
            stack.amount += resource.amount;
            filled = resource.amount;
        } else {
            stack.amount = capacity;
        }
        container.stackTagCompound.setTag("Fluid", stack.writeToNBT(fluidTag));
        return filled;
    }

    @Override
    public FluidStack drain(ItemStack container, int maxDrain, boolean doDrain) {

        if (container.stackTagCompound == null || !container.stackTagCompound.hasKey("Fluid")) {
            return null;
        }
        FluidStack stack = FluidStack.loadFluidStackFromNBT(container.stackTagCompound.getCompoundTag("Fluid"));

        if (stack == null) {
            return null;
        }
        stack.amount = Math.min(stack.amount, maxDrain);

        if (doDrain) {
            if (maxDrain >= capacity) {
                container.stackTagCompound.removeTag("Fluid");

                if (container.stackTagCompound.hasNoTags()) {
                    container.stackTagCompound = null;
                }
                return stack;
            }
            NBTTagCompound fluidTag = container.stackTagCompound.getCompoundTag("Fluid");
            fluidTag.setInteger("Amount", fluidTag.getInteger("Amount") - maxDrain);
            container.stackTagCompound.setTag("Fluid", fluidTag);
        }
        return stack;
    }

}