Bukkit custom inventory acting strange

Hello all,

I'm trying to make a simple API for my own plugin, to simply make custom inventories. It just... doesn't work as expected.


My InventoryAPI class:

PHP:

public class InventoryAPI {
    
    public static void setItem(Inventory inventory, int slot, ItemStack item) {
        inventory.setItem(slot, item);
    }
    
    public static void removeItem(Inventory inventory, ItemStack item) {
        inventory.removeItem(item);
    }
    
    public static void addItem(Inventory inventory, ItemStack item) {
        inventory.addItem(item);
    }
    
    public static void clearInv(Inventory inventory) {
        inventory.clear();
    }
    
    public static void openInventory(Player player, Inventory inventory) {
        player.openInventory(inventory);
    }
    
    public static void closeInventory(Player player) {
        player.closeInventory();
    }
}


My ItemStacks class:

PHP:

public class ItemStacks {
    
    public static ItemStack GameMenu() {
        ItemStack is = new ItemStack(Material.BOOK, 1);
        ItemMeta im = is.getItemMeta();
        im.setDisplayName(ChatColor.BLUE + "" + ChatColor.MAGIC + "|" + ChatColor.GOLD + " GameMenu " + ChatColor.BLUE
                + "" + ChatColor.MAGIC + "|");
        im.setLore(Arrays.asList(ChatColor.GOLD + "Gain the knowledge of this magical park."));
        is.addUnsafeEnchantment(Enchantment.THORNS, 10);
        is.setItemMeta(im);
        return is;
    }
    
    public static ItemStack Spawn() {
        ItemStack is = new ItemStack(Material.DIAMOND_BOOTS, 1);
        ItemMeta im = is.getItemMeta();
        im.setDisplayName(ChatColor.AQUA + "Spawn");
        im.setLore(Arrays.asList(ChatColor.DARK_AQUA + "Go to the spawn... With the speed of light!"));
        is.setItemMeta(im);
        return is;
    }
}


My inventory class:

PHP:

public class InventoryGameMenu implements Listener {
    private ThemeCraft plugin;
    
    public InventoryGameMenu(ThemeCraft plugin) {
        this.plugin = plugin;
    }
    
    @EventHandler
    public void onPlayerInteract(PlayerInteractEvent event) {
        Player player = event.getPlayer();
        if (((event.getAction() == Action.RIGHT_CLICK_AIR) || (event.getAction() == Action.RIGHT_CLICK_BLOCK))
                && (event.getPlayer().getItemInHand().equals(ItemStacks.GameMenu()))) {
            InventoryAPI.closeInventory(player);
            Inventory GameMenu = Bukkit.createInventory(null, 7*7, ChatColor.DARK_GRAY + "General information");
            InventoryAPI.setItem(GameMenu, 0, ItemStacks.Spawn());
            InventoryAPI.openInventory(player, GameMenu);
        }
    }
    
    @EventHandler
    public void onClick(InventoryClickEvent event) {
        Inventory GameMenu = Bukkit.createInventory(null, 7*7,
                ChatColor.DARK_GRAY + "General information");
        Player player = (Player) event.getWhoClicked();
        if (event.getInventory().getName().equalsIgnoreCase(GameMenu.getName())) {
            event.setCancelled(true);
            
            if (event.getCurrentItem() == null) {
                return;
            }
            
            if (event.getCurrentItem().equals(new ItemStack(ItemStacks.Spawn()))) {
                InventoryAPI.closeInventory(player);
                EffectsAPI.playSound(player, Sound.BURP, 1.0F, 1.0F);
                player.teleport(player.getWorld().getSpawnLocation());
            }
        }
    }
}


Does anyone know how this weird thing comes from?

 

You can't create inventories larger then 6 rows. Well, technically you can, but it will result them to display that weird.

 

Changing it to 6*6 actually solved it. Through I've always used 9*9, so I don't know why it didn't work this time.

 

size - The size of inventory to create; must be a multiple of 9.
You should use 9, 2*9, 3*9 etc. 6*6 = 36 = 9*4, that's why it solved it.

 

Ah, that explains it. Thanks.