InventoryUpgrades.java

package crazypants.enderio.conduit.gui.item;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.ItemStack;
import net.minecraftforge.common.util.ForgeDirection;
import crazypants.enderio.EnderIO;
import crazypants.enderio.conduit.item.IItemConduit;
import crazypants.enderio.conduit.item.filter.IItemFilterUpgrade;

public class InventoryUpgrades implements IInventory {

  IItemConduit itemConduit;
  ForgeDirection dir;
  
  public InventoryUpgrades(IItemConduit itemConduit, ForgeDirection dir) {
    this.itemConduit = itemConduit;
    this.dir = dir;
  }
  
  @Override
  public int getSizeInventory() {
    return 4;
  }

  @Override
  public ItemStack getStackInSlot(int slot) {
    switch (slot) {
      case 0: return itemConduit.getSpeedUpgrade(dir);
      case 1: return itemConduit.getFunctionUpgrade(dir);
      case 2: return itemConduit.getInputFilterUpgrade(dir);
      case 3: return itemConduit.getOutputFilterUpgrade(dir);
      default: return null;
    }
  }

  @Override
  public ItemStack decrStackSize(int slot, int num) {
    ItemStack current = getStackInSlot(slot);
    if(current == null) {
      return current;
    }
    ItemStack result;
    ItemStack remaining;
    if(num >= current.stackSize) {
      result = current.copy();
      remaining = null;
    } else {
      result = current.copy();
      result.stackSize = num;
      remaining = current.copy();
      remaining.stackSize -= num;
    }
    setInventorySlotContents(slot, remaining);
    return result;
  }

  @Override
  public ItemStack getStackInSlotOnClosing(int var1) {
    return null;
  }

  @Override
  public void setInventorySlotContents(int slot, ItemStack var2) {
    switch (slot) {
      case 0: itemConduit.setSpeedUpgrade(dir, var2); break;
      case 1: itemConduit.setFunctionUpgrade(dir, var2); break;
      case 2: itemConduit.setInputFilterUpgrade(dir, var2); break;
      case 3: itemConduit.setOutputFilterUpgrade(dir, var2); break;
    }
  }

  @Override
  public String getInventoryName() {
    return "Upgrades";
  }

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

  @Override
  public int getInventoryStackLimit() {
    return 15;
  }

  @Override
  public void markDirty() {      
  }

  @Override
  public boolean isUseableByPlayer(EntityPlayer var1) {
    return true;
  }

  @Override
  public void openInventory() {
  }

  @Override
  public void closeInventory() {
  }

  @Override
  public boolean isItemValidForSlot(int slot, ItemStack item) {
    if(item == null) {
      return false;
    }
    switch (slot) {
      case 0: return item.getItem() == EnderIO.itemExtractSpeedUpgrade;
      case 1: return item.getItem() == EnderIO.itemFunctionUpgrade;
      case 2:
      case 3: return item.getItem() instanceof IItemFilterUpgrade;
    }
    return false;
  }

}