New utility methods in InventoryUtil

src/com/massivecraft/mcore/util/InventoryUtil.java

@@ -1,11 +1,19 @@
 package com.massivecraft.mcore.util;
 
+import java.util.HashMap;
+
+import org.bukkit.Bukkit;
 import org.bukkit.craftbukkit.v1_4_R1.inventory.CraftInventoryCustom;
 import org.bukkit.inventory.Inventory;
 import org.bukkit.inventory.InventoryHolder;
+import org.bukkit.inventory.ItemStack;
 
 public class InventoryUtil
 {
+	// -------------------------------------------- //
+	// CREATE
+	// -------------------------------------------- //
+	
 	public static Inventory create(int size)
 	{
 		return create(null, size, "Chest");
@@ -25,4 +33,81 @@ public class InventoryUtil
 	{
 		return new CraftInventoryCustom(owner, size, title);
 	}
+	
+	// -------------------------------------------- //
+	// CLONE ITEMSTACKS/INVENTORY
+	// -------------------------------------------- //
+	
+	public static ItemStack[] cloneItemStacks(ItemStack[] itemStacks)
+	{
+		ItemStack[] ret = new ItemStack[itemStacks.length];
+		for (int i = 0; i < itemStacks.length; i++)
+		{
+			ItemStack stack = itemStacks[i];
+			if (stack == null) continue;
+			ret[i] = new ItemStack(itemStacks[i]);
+		}
+		return ret;
+	}
+	
+	// NOTE: This method may not be compatible with player inventories
+	public static Inventory cloneInventory(Inventory inventory)
+	{
+		if (inventory == null) return null;
+		
+		InventoryHolder holder = inventory.getHolder();
+		int size = inventory.getSize();
+		String title = inventory.getTitle();
+		ItemStack[] contents = cloneItemStacks(inventory.getContents());
+		
+		Inventory ret = Bukkit.createInventory(holder, size, title);
+		ret.setContents(contents);
+		
+		return ret;
+	}
+	
+	// -------------------------------------------- //
+	// CAN I ADD MANY?
+	// -------------------------------------------- //
+	
+	// Calculate how many times you could add this item to the inventory.
+	// NOTE: This method does not alter the inventory.
+	public static int roomLeft(Inventory inventory, ItemStack item, int limit)
+	{
+		inventory = cloneInventory(inventory);
+		int ret = 0;
+		while(limit <= 0 || ret < limit)
+		{
+			HashMap<Integer, ItemStack> result = inventory.addItem(item.clone());
+			if (result.size() != 0) return ret;
+			ret++;
+		}
+		return ret;
+	}
+	
+	// NOTE: Use the roomLeft method first to ensure this method would succeed
+	public static void addItemTimes(Inventory inventory, ItemStack item, int times)
+	{
+		for (int i = 0 ; i < times ; i++)
+		{
+			inventory.addItem(item.clone());
+		}
+	}
+	
+	// -------------------------------------------- //
+	// COUNT
+	// -------------------------------------------- //
+	
+	public static int countSimilar(Inventory inventory, ItemStack itemStack)
+	{
+		int ret = 0;
+		for (ItemStack item : inventory.getContents())
+		{
+			if (item == null) continue;
+			if (!item.isSimilar(itemStack)) continue;
+			ret += item.getAmount();
+		}
+		return ret;
+	}
+
 }