src/game/java/net/minecraft/world/CompoundContainer.java

package net.minecraft.world;

import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;

public class CompoundContainer implements Container {
    private final Container container1;
    private final Container container2;

    public CompoundContainer(Container p_18913_, Container p_18914_) {
        this.container1 = p_18913_;
        this.container2 = p_18914_;
    }

    @Override
    public int getContainerSize() {
        return this.container1.getContainerSize() + this.container2.getContainerSize();
    }

    @Override
    public boolean isEmpty() {
        return this.container1.isEmpty() && this.container2.isEmpty();
    }

    public boolean contains(Container p_18928_) {
        return this.container1 == p_18928_ || this.container2 == p_18928_;
    }

    @Override
    public ItemStack getItem(int p_18920_) {
        return p_18920_ >= this.container1.getContainerSize() ? this.container2.getItem(p_18920_ - this.container1.getContainerSize()) : this.container1.getItem(p_18920_);
    }

    @Override
    public ItemStack removeItem(int p_18922_, int p_18923_) {
        return p_18922_ >= this.container1.getContainerSize()
            ? this.container2.removeItem(p_18922_ - this.container1.getContainerSize(), p_18923_)
            : this.container1.removeItem(p_18922_, p_18923_);
    }

    @Override
    public ItemStack removeItemNoUpdate(int p_18932_) {
        return p_18932_ >= this.container1.getContainerSize() ? this.container2.removeItemNoUpdate(p_18932_ - this.container1.getContainerSize()) : this.container1.removeItemNoUpdate(p_18932_);
    }

    @Override
    public void setItem(int p_18925_, ItemStack p_18926_) {
        if (p_18925_ >= this.container1.getContainerSize()) {
            this.container2.setItem(p_18925_ - this.container1.getContainerSize(), p_18926_);
        } else {
            this.container1.setItem(p_18925_, p_18926_);
        }
    }

    @Override
    public int getMaxStackSize() {
        return this.container1.getMaxStackSize();
    }

    @Override
    public void setChanged() {
        this.container1.setChanged();
        this.container2.setChanged();
    }

    @Override
    public boolean stillValid(Player p_18930_) {
        return this.container1.stillValid(p_18930_) && this.container2.stillValid(p_18930_);
    }

    @Override
    public void startOpen(Player p_18940_) {
        this.container1.startOpen(p_18940_);
        this.container2.startOpen(p_18940_);
    }

    @Override
    public void stopOpen(Player p_18937_) {
        this.container1.stopOpen(p_18937_);
        this.container2.stopOpen(p_18937_);
    }

    @Override
    public boolean canPlaceItem(int p_18934_, ItemStack p_18935_) {
        return p_18934_ >= this.container1.getContainerSize()
            ? this.container2.canPlaceItem(p_18934_ - this.container1.getContainerSize(), p_18935_)
            : this.container1.canPlaceItem(p_18934_, p_18935_);
    }

    @Override
    public void clearContent() {
        this.container1.clearContent();
        this.container2.clearContent();
    }
}