Item Inventory Issue

Hi everyone

So i have started to try adding some interfaces/inventories to my items and I have hit an issue trying to apply it to my item.

The item is an egg launcher that I want the player to be able toshoot eggs for guaranteed hatching if the invenory has an egg in it.

However there is a problem, as when I open the inventory and place an item in a slot it duplicates it by adding it to the slot and keeping the item in my selected item  and when left clicking to take the item from the slot the items simply disappear. Any advice?

(if it helps I am following VSWEs tutorial series for 1.6 and trying to bring it over for 1.7)

Item class

package items;

import cpw.mods.fml.common.network.internal.FMLNetworkHandler;
import entities.FunEgg;
import entities.PotatoGrenade;
import keystuff.myMod;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.projectile.EntitySnowball;
import net.minecraft.init.Items;
import net.minecraft.inventory.IInventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemSnowball;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;

public class BlasterThingy extends ItemSnowball implements IInventory
{
   public BlasterThingy()
   {
      super();
      setCreativeTab(myMod.daftcraft);
      setUnlocalizedName("blaster thingy");
      setMaxDamage(300);


   }

   @Override
   public ItemStack onItemRightClick(ItemStack itemStack, World world, EntityPlayer player)
   {

      String checkName="ForgeDevName";
      String name=player.getDisplayName();

      if(player.isSneaking())
      {
         FMLNetworkHandler.openGui(player, myMod.modInstance, 0, world, (int) player.posX, (int) player.posY, (int) player.posZ);
      }


      if (!player.capabilities.isCreativeMode)
      {
         if(getStackInSlot(0)!= null)
         {
            if(doesInventoryContain(Items.egg) && !player.isSneaking())
            {
            world.spawnEntityInWorld(new FunEgg(world, player));
            this.decrStackSize(0,1);
            //player.inventory.consumeInventoryItem(Items.egg);

            itemStack.setItemDamage(itemStack.getItemDamage()+1);
            return itemStack;
            }
         }

         System.out.println(this.getStackInSlot(0));


      }
      else
      {
         if(!player.isSneaking())
         {
            world.spawnEntityInWorld(new FunEgg(world, player));
         }

      }






      world.playSoundAtEntity(player, "random.bow", 0.5F, 0.4F / (itemRand.nextFloat() * 0.4F + 0.8F));



      return itemStack;
   }


                                 //begining of Inventory Code
   ItemStack[] items=new ItemStack[3];

   @Override
   public int getSizeInventory() {
      return items.length;
   }

   @Override
   public ItemStack getStackInSlot(int slot)
   {
      return items[slot];
   }

   public boolean doesInventoryContain(Item item)
   {
      for(int count=0;count < items.length;count++)
      {
         if(items[count].getItem()==item)
         {
            return true;
         }
      }

      return false;
   }

   @Override
   public ItemStack decrStackSize(int slot, int count)
   {
      ItemStack itemstack=getStackInSlot(slot);

      if(itemstack !=null)
      {
         if(itemstack.stackSize <= count)
         {
            setInventorySlotContents(slot,null);
         }
         else
         {
            itemstack =itemstack.splitStack(count);

         }
      }

      return itemstack;
   }

   @Override
   public ItemStack getStackInSlotOnClosing(int slot)
   {
      ItemStack itemstack=getStackInSlot(slot);
      setInventorySlotContents(slot,null);
      return itemstack;
   }

   @Override
   public void setInventorySlotContents(int slot, ItemStack itemStack)
   {
      items[slot]=itemStack;

      if(itemStack !=null && itemStack.stackSize > getInventoryStackLimit())
      {
         itemStack.stackSize=getInventoryStackLimit();
      }
   }

   @Override
   public String getInventoryName() {
      return null;
   }

   @Override
   public boolean hasCustomInventoryName() {
      return false;  //To change body of implemented methods use File | Settings | File Templates.
   }

   @Override
   public int getInventoryStackLimit() {
      return 64;  //To change body of implemented methods use File | Settings | File Templates.
   }

   @Override
   public void markDirty()
   {

   }

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

   @Override
   public void openInventory() {}

   @Override
   public void closeInventory() {}

   @Override
   public boolean isItemValidForSlot(int slot, ItemStack itemStack)
   {
      return itemStack.getItem()== Items.egg;

   }

   }

GUI class

@SideOnly(Side.CLIENT)
public class GUIBow extends GuiContainer
{

   public GUIBow(InventoryPlayer inventoryPlayer, ItemStack bow)
   {
      super(new BowContainer(inventoryPlayer,bow));
      xSize=176;
      ySize=154;
   }

   private static final ResourceLocation texture=new ResourceLocation(myMod.MODID, "textures/gui/machine.png");

   @Override
   protected void drawGuiContainerBackgroundLayer(float p_146976_1_, int x, int y)
   {
      GL11.glColor4f(1,1,1,1);
      Minecraft.getMinecraft().getTextureManager().bindTexture(texture);
      drawTexturedModalRect(guiLeft,guiTop,0,0,xSize,ySize);

   }

   @Override
   protected void drawGuiContainerForegroundLayer(int x, int y)
   {
      fontRendererObj.drawString("blaster container",8,6,0x40404040);
   }

   @Override
   public void initGui()
   {
      super.initGui();
      buttonList.clear();

      buttonList.add(new GuiButton(0,guiLeft+100,guiTop+14,60,20,"disable"));
   }

  
}//class

GUI handler class

package GUIStuff;

import cpw.mods.fml.common.network.IGuiHandler;
import cpw.mods.fml.common.network.NetworkRegistry;
import items.BlasterThingy;
import items.TestBow;
import items.daftcraftItems;
import keystuff.myMod;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;


public class GUIHandler implements IGuiHandler
{

   public GUIHandler()
   {
      NetworkRegistry.INSTANCE.registerGuiHandler(myMod.modInstance,this);
   }

   @Override
   public Object getServerGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z)
   {
      switch(ID)
      {

         case 0:
            ItemStack bow=player.getHeldItem();
            if(bow !=null && bow.getItem()instanceof BlasterThingy)
            {
               return new BowContainer(player.inventory,bow);
            }
            break;
      }
      return null;
   }

   @Override
   public Object getClientGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z)
   {
      switch(ID)
      {

         case 0:
            ItemStack bow=player.getHeldItem();
            if(bow !=null && bow.getItem()instanceof BlasterThingy)
            {
               return new GUIBow(player.inventory,bow);
            }
            break;
      }
      return null;
   }
}//class

GUI container class

public class BowContainer extends Container
{
   private ItemStack bow;
   private BlasterThingy blaster;


   public BowContainer(InventoryPlayer inventoryPlayer, ItemStack bow)
   {
      this.bow=bow;

      if(inventoryPlayer.player.getHeldItem().getItem()==daftcraftItems.blasterThingy)
      {
         blaster=(BlasterThingy)inventoryPlayer.player.getHeldItem().getItem();
      }

      for(int x=0;x<9;x++)
      {
         addSlotToContainer(new Slot(inventoryPlayer,x,8+18*x,130));
      }

      for(int y=0;y<3;y++)
      {
         for(int x=0;x<9;x++)
         {
            addSlotToContainer(new Slot(inventoryPlayer,x+y*9+9,8+18*x,72+y*18));
         }
      }

      for(int x=0;x<3;x++)
      {
         addSlotToContainer(new ProjectileSlot(blaster,x,8+18*x,17));
      }
   }

   @Override
   public boolean canInteractWith(EntityPlayer player)
   {
      return true;
   }

   @Override
   public ItemStack transferStackInSlot(EntityPlayer p_82846_1_, int p_82846_2_)
   {
      return null;
   }
}//class

Any help is appreciated