TileEntityAlloyOven Class

package com.arucraft.tileentity;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Items;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.tileentity.TileEntity;

public class TileEntityAlloyOven extends TileEntity implements IInventory{

    private ItemStack slots[];

    public int tripPower;
    public int tripCooktime;

    private String CustomName;

    public TileEntityAlloyOven() {
        slots = new ItemStack[5];
    }
    @Override
    public int getSizeInventory() {
        return slots.length;
    }
    @Override
    public ItemStack getStackInSlot(int i) {
        return slots[i];
    }
    @Override
    public ItemStack decrStackSize(int i, int j) {
        if (slots[i] != null) {
            if (slots[i].stackSize <= j) {
                ItemStack itemstack = slots[i];
                slots[i] = null;
                return itemstack;
            }

            ItemStack itemstack1 = slots[i].splitStack(j);

            if (slots[i].stackSize == 0) {
                slots[i] = null;
            }

            return itemstack1;
        }else{
            return null;
        }
    }
    @Override
    public ItemStack getStackInSlotOnClosing(int p_70304_1_) {
        // TODO Auto-generated method stub
        return null;
    }
    @Override
    public void setInventorySlotContents(int i, ItemStack itemstack) {
        slots[i] = itemstack;
        if (itemstack != null && itemstack.stackSize > getInventoryStackLimit()) {
            itemstack.stackSize = getInventoryStackLimit();
        }



    }

    public void setGuiDisplayName (String name) {
        this.CustomName = name;

    }
    @Override
    public String getInventoryName() {
        return this.hasCustomInventoryName() ? this.CustomName : "container.alloyoven";
    }
    @Override
    public boolean hasCustomInventoryName() {
        return this.CustomName != null && this.CustomName.length() > 0;


    }
    @Override
    public int getInventoryStackLimit() {
        return 64;
    }
    @Override
    public boolean isUseableByPlayer(EntityPlayer player) {
        if (worldObj.getTileEntity(xCoord, yCoord, zCoord) != this) {
            return false;

        }else{
            return player.getDistanceSq((double)xCoord + 0.5D, (double)yCoord + 0.5D, (double)zCoord + 0.5D) <+ 64;
        }
    }

    public void openInventory() {}
    public void closeInventory() {}

    @Override
    public boolean isItemValidForSlot(int i, ItemStack itemstack) {
        return i == 3 ? false : (i == 1 ? hasItemPower(itemstack) : true);
    }

    public boolean hasItemPower(ItemStack itemstack) {
        return getItemPower(itemstack) > 0;
    }

    private static int getItemPower (ItemStack itemstack) {
        if (itemstack == null) {
            return 0;
        }else{
            Item item = itemstack.getItem();

            if (item == Items.coal) return 50;

            return 0;
        }
    }


}