GUIObject

/* Example Custom GUI Object
 * I borrowed this code from the spigot wiki there are many advantages to doing this vs using the plain old inventory object from bukkit.
 * https://www.spigotmc.org/wiki/creating-a-gui-inventory/
 * 
 * The great thing about this is you can easily identify YOUR gui and handle events for YOUR gui rather than trying to identify it in a regular listener
 * class by name.
 */


package Util;

import java.util.Arrays;

import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.entity.HumanEntity;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.InventoryHolder;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;

public class GuiObject implements InventoryHolder, Listener 
{
	private final Inventory inv;

	public GuiObject()
	{
		// Create a new inventory, with "this" owner for comparison with other inventories, a size of nine, called example
		inv = Bukkit.createInventory(this, 9, "Example");

		// Put the items into the inventory
		initializeItems();
	}

	@Override
	public Inventory getInventory()
	{
		return inv;
	}

	// You can call this whenever you want to put the items in or use your existing gui code
	public void initializeItems()
	{
		inv.addItem(createGuiItem(Material.DIAMOND_SWORD, "Example Sword", "§aFirst line of the lore", "§bSecond line of the lore"));
		inv.addItem(createGuiItem(Material.IRON_HELMET, "§bExample Helmet", "§aFirst line of the lore", "§bSecond line of the lore"));
	}

	// Nice little method to create a gui item with a custom name, and description
	protected ItemStack createGuiItem(final Material material, final String name, final String... lore)
	{
		final ItemStack item = new ItemStack(material, 1);
		final ItemMeta meta = item.getItemMeta();

		// Set the name of the item
		meta.setDisplayName(name);

		// Set the lore of the item
		meta.setLore(Arrays.asList(lore));

		item.setItemMeta(meta);

		return item;
	}

	// You can open the inventory with this
	public void openInventory(final HumanEntity ent)
	{
		ent.openInventory(inv);
	}



/* Highly recommend using this method as you can easily identify YOUR custom inventory object by simply doing
 * if(inventory.getHolder() instanceof GuiObject) 
 */
	
	@EventHandler
	public void onInventoryClick(final InventoryClickEvent e)
	{
		if (e.getInventory().getHolder() != this) return;

		e.setCancelled(true);

		final ItemStack clickedItem = e.getCurrentItem();

		// verify current item is not null
		if (clickedItem == null || clickedItem.getType() == Material.AIR) return;

		final Player p = (Player) e.getWhoClicked();

		// Using slots click is a best option for your inventory click's
		p.sendMessage("You clicked at slot " + e.getRawSlot());
	}

}```