InventoryHelper.java

package com.flansmod.common.guns;

import net.minecraft.inventory.IInventory;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NBTTagCompound;

/** Adds access to the InventoryPlayer stack combination methods for arbitrary inventories */
public class InventoryHelper 
{
	public static boolean addItemStackToInventory(IInventory inventory, ItemStack stack, boolean creative)
	{
		if(stack == null)
			return false;
		else if(stack.stackSize == 0)
			return false;
		else
		{
			try
			{
				int i;

				if (stack.isItemDamaged())
				{
					i = getFirstEmptyStack(inventory);

					if (i >= 0)
					{
						ItemStack stackToAdd = ItemStack.copyItemStack(stack);
						stackToAdd.animationsToGo = 5;
						inventory.setInventorySlotContents(i, stackToAdd);
						stack.stackSize = 0;
						return true;
					}
					else if(creative)
					{
						stack.stackSize = 0;
						return true;
					}
					return false;
				}
				else
				{
					do
					{
						i = stack.stackSize;
						stack.stackSize = storePartialItemStack(inventory, stack);
					}
					while (stack.stackSize > 0 && stack.stackSize < i);

					if (stack.stackSize == i && creative)
					{
						stack.stackSize = 0;
						return true;
					}
					else
					{
						return stack.stackSize < i;
					}
				}
			}
			catch (Throwable throwable)
			{
				throwable.printStackTrace();
				return false;
			}
		}
	}
	
	public static int storeItemStack(IInventory inventory, ItemStack stack)
	{
		for (int i = 0; i < inventory.getSizeInventory(); ++i)
		{
			ItemStack oldStack = inventory.getStackInSlot(i);
			if (oldStack != null && oldStack.getItem() == stack.getItem() && oldStack.isStackable() && oldStack.stackSize < oldStack.getMaxStackSize() && oldStack.stackSize < inventory.getInventoryStackLimit() && (!oldStack.getHasSubtypes() || oldStack.getItemDamage() == stack.getItemDamage()) && ItemStack.areItemStackTagsEqual(oldStack, stack))
			{
				return i;
			}
		}

		return -1;
	}
	
	public static int storePartialItemStack(IInventory inventory, ItemStack stack)
	{
		Item item = stack.getItem();
		int j = stack.stackSize;
		int k;

		//If the item doesn't stack, just find an empty slot for it
		if(stack.getMaxStackSize() == 1)
		{
			k = getFirstEmptyStack(inventory);
			//If it is impossible, return
			if (k < 0)
			{
				return j;
			}
			else
			{
				if(inventory.getStackInSlot(k) == null)
				{
					inventory.setInventorySlotContents(k, ItemStack.copyItemStack(stack));
				}
				return 0;
			}
		}
		else
		{
			k = storeItemStack(inventory, stack);
			if (k < 0)
			{
				k = getFirstEmptyStack(inventory);
			}

			if (k < 0)
			{
				return j;
			}
			else
			{
				ItemStack oldStack = inventory.getStackInSlot(k);

				if(oldStack == null)
				{
					oldStack = new ItemStack(item, 0, stack.getItemDamage());
					if(stack.hasTagCompound())
						oldStack.setTagCompound((NBTTagCompound)stack.getTagCompound().copy());
					inventory.setInventorySlotContents(k, oldStack);
				}

				int l = j;

				if(j > oldStack.getMaxStackSize() - oldStack.stackSize)
				{
					l = oldStack.getMaxStackSize() - oldStack.stackSize;
				}

				if (l > inventory.getInventoryStackLimit() - oldStack.stackSize)
				{
					l = inventory.getInventoryStackLimit() - oldStack.stackSize;
				}

				if (l == 0)
				{
					return j;
				}
				else
				{
					j -= l;
					oldStack.stackSize += l;
					oldStack.animationsToGo = 5;
					return j;
				}
			}
		}
	}
	
	/** Method from InventoryPlayer */
	public static int getFirstEmptyStack(IInventory inventory)
	{
		for(int i = 0; i < inventory.getSizeInventory(); ++i)
			if (inventory.getStackInSlot(i) == null)
				return i;

		return -1;
	}
	
}