ContainerNPC.class

package net.rexozz.pixelengine.server.container;

import javax.annotation.Nullable;

import net.minecraft.entity.EntityLiving;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.Container;
import net.minecraft.inventory.EntityEquipmentSlot;
import net.minecraft.inventory.IInventory;
import net.minecraft.inventory.Slot;
import net.minecraft.item.ItemArmor;
import net.minecraft.item.ItemStack;
import net.minecraftforge.fml.relauncher.Side;
import net.minecraftforge.fml.relauncher.SideOnly;
import net.rexozz.pixelengine.entity.EntityNPC;

public class ContainerNPC extends Container{

    private EntityNPC npc;
    public IInventory inventoryNPC;
    private static final EntityEquipmentSlot[] VALID_ARMOR_SLOTS = new EntityEquipmentSlot[] {EntityEquipmentSlot.HEAD, EntityEquipmentSlot.CHEST, EntityEquipmentSlot.LEGS, EntityEquipmentSlot.FEET};

    private int
    ARMOR_START=0,
    ARMOR_END=ARMOR_START+3,
    MAIN_OFFHAND_START=ARMOR_END+1,
    MAIN_OFFHAND_END=MAIN_OFFHAND_START+1,
    INV_PLAYER_START=MAIN_OFFHAND_END+1,
    INV_PLAYER_END=INV_PLAYER_START+26,
    HOTBAR_PLAYER_START=INV_PLAYER_END+1,
    HOTBAR_PLAYER_END=HOTBAR_PLAYER_START+8;

    public ContainerNPC(IInventory playerInventory, final IInventory npcInventory, final EntityNPC npc, EntityPlayer player){
        this.npc=npc;
        this.inventoryNPC=npcInventory;

        for (int k = 0; k < 4; k++){
            final EntityEquipmentSlot entityequipmentslot = VALID_ARMOR_SLOTS[k];
            this.addSlotToContainer(new Slot(npcInventory, k, 8, 8 + k * 18){
                public int getSlotStackLimit() {
                    return 1;
                }

                public boolean isItemValid(@Nullable ItemStack stack){
                    if (stack == null)
                        return false;
                    else
                        return stack.getItem().isValidArmor(stack, entityequipmentslot, npc);
                }
                @Nullable
                @SideOnly(Side.CLIENT)
                public String getSlotTexture(){
                    return ItemArmor.EMPTY_SLOT_NAMES[entityequipmentslot.getIndex()];
                }
            });
        }

        this.addSlotToContainer(new Slot(npcInventory,4, 20, 0){
            public int getSlotStackLimit() {
                return 1;
            }

            public boolean isItemValid(@Nullable ItemStack stack){
                if (stack == null)
                    return false;
                else
                    return EntityLiving.getSlotForItemStack(stack)==EntityEquipmentSlot.OFFHAND;
            }
        });
        this.addSlotToContainer(new Slot(npcInventory,5, 38, 0));

        for (int i = 0; i < 3; ++i) {
            for (int j = 0; j < 9; ++j)
                this.addSlotToContainer(new Slot(playerInventory, j+i*9+9, 8 + j * 18, 84 + i * 18));
        }

        for (int k = 0; k < 9; ++k)
            this.addSlotToContainer(new Slot(playerInventory, k, 8 + k * 18, 142));
    }

    public boolean canInteractWith(EntityPlayer playerIn) {
        return this.inventoryNPC.isUseableByPlayer(playerIn)&&this.npc.isEntityAlive();
    }

    @Nullable
    public ItemStack transferStackInSlot(EntityPlayer playerIn, int index) {
         ItemStack itemstack = null;
         Slot slot = (Slot)this.inventorySlots.get(index);
         if (slot != null && slot.getHasStack()){
             ItemStack itemstack1 = slot.getStack();
             itemstack = itemstack1.copy();
             EntityEquipmentSlot entityequipmentslot = EntityLiving.getSlotForItemStack(itemstack);

             if(index<INV_PLAYER_START){
                 if(!this.mergeItemStack(itemstack1, INV_PLAYER_START, HOTBAR_PLAYER_END+1, true))
                     return null;
                 slot.onSlotChange(itemstack1, itemstack);
             }else{
                 if(entityequipmentslot.getSlotType()==EntityEquipmentSlot.Type.ARMOR&&!((Slot)this.inventorySlots.get(3-entityequipmentslot.getIndex())).getHasStack()){
                     int i=3-entityequipmentslot.getIndex();
                     if(!this.mergeItemStack(itemstack1, i, i+1, false));
                        return null;
                 }else if(entityequipmentslot==EntityEquipmentSlot.OFFHAND&&!((Slot)this.inventorySlots.get(4)).getHasStack()){
                     if(!this.mergeItemStack(itemstack1, 4, 5, false));
                        return null;
                 }else if(entityequipmentslot==EntityEquipmentSlot.MAINHAND&&!((Slot)this.inventorySlots.get(5)).getHasStack()){
                     if(!this.mergeItemStack(itemstack1, 5, 6, false));
                        return null;
                 }else if(index>INV_PLAYER_START&&index<INV_PLAYER_END+1){
                     if(!this.mergeItemStack(itemstack1, HOTBAR_PLAYER_START, HOTBAR_PLAYER_END+1, false));
                        return null;
                 }else if(index>HOTBAR_PLAYER_START&&index<HOTBAR_PLAYER_END+1){
                     if(!this.mergeItemStack(itemstack1, INV_PLAYER_START, INV_PLAYER_END+1, false));
                        return null;
                 }else{
                     if(!this.mergeItemStack(itemstack1, INV_PLAYER_START, HOTBAR_PLAYER_END+1, false));
                    return null;
                 }
             }

             if (itemstack1.stackSize == 0)
                 slot.putStack((ItemStack)null);
             else
                 slot.onSlotChanged();

             if (itemstack1.stackSize == itemstack.stackSize)
                 return null;

             slot.onPickupFromSlot(playerIn, itemstack1);
         }

         return itemstack;
    }

    public void onContainerClosed(EntityPlayer player) {
        super.onContainerClosed(player);
        this.inventoryNPC.closeInventory(player);
    }
}