ItemSet.java

import java.util.Arrays;
import java.util.List;

import org.bukkit.ChatColor;
import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerInteractEvent;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
import org.bukkit.plugin.Plugin;

public enum ItemSet {
	TEST(Material.QUARTZ, ChatColor.GREEN + "Test",
			Arrays.asList(ChatColor.GRAY + "This is a test",
					ChatColor.GRAY + "Lorem ipsum dolor sit amet, consectetuer adipiscing elit"),
			false, new EventCallback() {
				@Override
				public void call(PlayerInteractEvent event, Plugin plugin) {
					Player player = event.getPlayer();
				}
			});

	private final ItemStack item;
	private final boolean interactable;
	private final EventCallback eventCallback;

	private ItemSet(ItemStack item, boolean interactable, EventCallback eventCallback) {
		this.item = item;
		this.interactable = interactable;
		this.eventCallback = eventCallback;
	}

	private ItemSet(Material material, String name, List<String> lore, boolean interactable, EventCallback eventCallback) {
		item = new ItemStack(material);
		ItemMeta meta = item.getItemMeta();
		meta.setDisplayName(name);
		meta.setLore(lore);
		item.setItemMeta(meta);
		this.interactable = interactable;
		this.eventCallback = eventCallback;
	}

	public ItemStack getItemStack() {
		return item;
	}

	public boolean isInteractable() {
		return interactable;
	}

	public EventCallback getEventCallback() {
		return eventCallback;
	}

	public static abstract class EventCallback {
		public abstract void call(PlayerInteractEvent event, Plugin plugin);
	}

	private static ItemListener listener;

	public static void startListening(Plugin plugin) {
		listener = new ItemListener(plugin);
		plugin.getServer().getPluginManager().registerEvents(listener, plugin);
	}

	public static class ItemListener implements Listener {
		private final Plugin plugin;
		public ItemListener(Plugin plugin) {
			this.plugin = plugin;
		}

		@EventHandler
		public void onInteract(PlayerInteractEvent event) {
			ItemStack item = event.getItem();
			for (ItemSet set : values()) {
				if (set.getItemStack().equals(item)) {
					if (set.getEventCallback() != null) {
						set.getEventCallback().call(event, plugin);
					}
					if (set.isInteractable()) return;
					event.setCancelled(true);
					break;
				}
			}
		}
	}
}