minecraft-src/net/minecraft/world/entity/vehicle/MinecartHopper.java

package net.minecraft.world.entity.vehicle;

import net.minecraft.core.BlockPos;
import net.minecraft.world.entity.EntitySelector;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.item.ItemEntity;
import net.minecraft.world.entity.player.Inventory;
import net.minecraft.world.inventory.AbstractContainerMenu;
import net.minecraft.world.inventory.HopperMenu;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.entity.Hopper;
import net.minecraft.world.level.block.entity.HopperBlockEntity;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.block.state.properties.RailShape;
import net.minecraft.world.level.storage.ValueInput;
import net.minecraft.world.level.storage.ValueOutput;

public class MinecartHopper extends AbstractMinecartContainer implements Hopper {
	private static final boolean DEFAULT_ENABLED = true;
	private boolean enabled = true;
	private boolean consumedItemThisFrame = false;

	public MinecartHopper(EntityType<? extends MinecartHopper> entityType, Level level) {
		super(entityType, level);
	}

	@Override
	public BlockState getDefaultDisplayBlockState() {
		return Blocks.HOPPER.defaultBlockState();
	}

	@Override
	public int getDefaultDisplayOffset() {
		return 1;
	}

	@Override
	public int getContainerSize() {
		return 5;
	}

	@Override
	public void activateMinecart(int x, int y, int z, boolean powered) {
		boolean bl = !powered;
		if (bl != this.isEnabled()) {
			this.setEnabled(bl);
		}
	}

	/**
	 * Get whether this hopper minecart is being blocked by an activator rail.
	 */
	public boolean isEnabled() {
		return this.enabled;
	}

	/**
	 * Set whether this hopper minecart is being blocked by an activator rail.
	 */
	public void setEnabled(boolean enabled) {
		this.enabled = enabled;
	}

	@Override
	public double getLevelX() {
		return this.getX();
	}

	@Override
	public double getLevelY() {
		return this.getY() + 0.5;
	}

	@Override
	public double getLevelZ() {
		return this.getZ();
	}

	@Override
	public boolean isGridAligned() {
		return false;
	}

	@Override
	public void tick() {
		this.consumedItemThisFrame = false;
		super.tick();
		this.tryConsumeItems();
	}

	@Override
	protected double makeStepAlongTrack(BlockPos pos, RailShape railShape, double speed) {
		double d = super.makeStepAlongTrack(pos, railShape, speed);
		this.tryConsumeItems();
		return d;
	}

	private void tryConsumeItems() {
		if (!this.level().isClientSide && this.isAlive() && this.isEnabled() && !this.consumedItemThisFrame && this.suckInItems()) {
			this.consumedItemThisFrame = true;
			this.setChanged();
		}
	}

	public boolean suckInItems() {
		if (HopperBlockEntity.suckInItems(this.level(), this)) {
			return true;
		} else {
			for (ItemEntity itemEntity : this.level()
				.getEntitiesOfClass(ItemEntity.class, this.getBoundingBox().inflate(0.25, 0.0, 0.25), EntitySelector.ENTITY_STILL_ALIVE)) {
				if (HopperBlockEntity.addItem(this, itemEntity)) {
					return true;
				}
			}

			return false;
		}
	}

	@Override
	protected Item getDropItem() {
		return Items.HOPPER_MINECART;
	}

	@Override
	public ItemStack getPickResult() {
		return new ItemStack(Items.HOPPER_MINECART);
	}

	@Override
	protected void addAdditionalSaveData(ValueOutput output) {
		super.addAdditionalSaveData(output);
		output.putBoolean("Enabled", this.enabled);
	}

	@Override
	protected void readAdditionalSaveData(ValueInput input) {
		super.readAdditionalSaveData(input);
		this.enabled = input.getBooleanOr("Enabled", true);
	}

	@Override
	public AbstractContainerMenu createMenu(int containerId, Inventory playerInventory) {
		return new HopperMenu(containerId, playerInventory, this);
	}
}