Add count method to InventoryUtils

src/main/java/net/wurstclient/util/InventoryUtils.java

@@ -67,6 +67,59 @@ public enum InventoryUtils
 	 */
 	public static int indexOf(Predicate<ItemStack> predicate, int maxInvSlot,
 		boolean includeOffhand)
+	{
+		return getMatchingSlots(predicate, maxInvSlot, includeOffhand)
+			.findFirst().orElse(-1);
+	}
+	
+	public static int count(Item item)
+	{
+		return count(stack -> stack.isOf(item), 36, false);
+	}
+	
+	public static int count(Item item, int maxInvSlot)
+	{
+		return count(stack -> stack.isOf(item), maxInvSlot, false);
+	}
+	
+	public static int count(Item item, int maxInvSlot, boolean includeOffhand)
+	{
+		return count(stack -> stack.isOf(item), maxInvSlot, includeOffhand);
+	}
+	
+	public static int count(Predicate<ItemStack> predicate)
+	{
+		return count(predicate, 36, false);
+	}
+	
+	public static int count(Predicate<ItemStack> predicate, int maxInvSlot)
+	{
+		return count(predicate, maxInvSlot, false);
+	}
+	
+	/**
+	 * Counts the number of items in the player's inventory that match the given
+	 * predicate, searching from slot 0 to {@code maxInvSlot-1}.
+	 *
+	 * @param predicate
+	 *            checks if an item should be counted
+	 * @param maxInvSlot
+	 *            the maximum slot to search (exclusive), usually 9 for the
+	 *            hotbar or 36 for the whole inventory
+	 * @param includeOffhand
+	 *            also search the offhand (slot 40), even if maxInvSlot is lower
+	 * @return
+	 *         the number of matching items in the player's inventory
+	 */
+	public static int count(Predicate<ItemStack> predicate, int maxInvSlot,
+		boolean includeOffhand)
+	{
+		return (int)getMatchingSlots(predicate, maxInvSlot, includeOffhand)
+			.count();
+	}
+	
+	private static IntStream getMatchingSlots(Predicate<ItemStack> predicate,
+		int maxInvSlot, boolean includeOffhand)
 	{
 		PlayerInventory inventory = MC.player.getInventory();
 		
@@ -75,11 +128,8 @@ public enum InventoryUtils
 		if(includeOffhand)
 			stream = IntStream.concat(stream, IntStream.of(40));
 		
-		// find the slot of the item we want
-		int slot = stream.filter(i -> predicate.test(inventory.getStack(i)))
-			.findFirst().orElse(-1);
-		
-		return slot;
+		// filter out the slots we don't want
+		return stream.filter(i -> predicate.test(inventory.getStack(i)));
 	}
 	
 	public static boolean selectItem(Item item)