Menu-System Konzept, tested

HowToOpen.java

//HowToOpen first Menu
MenuRegistery#open(null, new OneMenu((Player) arg0, getMenuRegistery()));

Menu.java

package ap.apbuy.menu;

import java.util.regex.Pattern;

import org.bukkit.Bukkit;
import org.bukkit.entity.Player;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryCloseEvent;
import org.bukkit.inventory.Inventory;

import ap.apbuy.APBuy;

public abstract class Menu {
	private Player viewer;
	private String title;
	private int size;
	private Menu prevMenu;
	private MenuRegistery menuRegistery;
	private boolean ignoreClose;
	private APBuy plugin;

	public Menu(Player viewer, String title, int size, Menu prevMenu, MenuRegistery menuRegistery) {
		this.viewer = viewer;
		this.title = title;
		this.size = size;
		this.prevMenu = prevMenu;
		this.menuRegistery = menuRegistery;
		this.plugin = menuRegistery.getPlugin();
	}

	public Menu(Player viewer, String title, int size, Menu prevMenu) {
		this.viewer = viewer;
		this.title = title;
		this.size = size;
		this.prevMenu = prevMenu;
		this.menuRegistery = prevMenu.getMenuRegistery();
		this.plugin = prevMenu.getPlugin();
	}

	public Menu(Player viewer, String title, int size, MenuRegistery menuRegistery) {
		this.viewer = viewer;
		this.title = title;
		this.size = size;
		this.menuRegistery = menuRegistery;
		this.plugin = menuRegistery.getPlugin();
	}

	public void open() {
		this.setIgnoreClose(true);
		this.getViewer()
				.openInventory(this.assembleInventory(Bukkit.createInventory(null, this.getSize(), this.getTitle())));
		this.setIgnoreClose(false);
	}

	public abstract Inventory assembleInventory(Inventory inventory);

	public void open(Menu menu) {
		System.out.println(this.getViewer().getName() + ": " + getClassName(this.getClass()) + " -> "
				+ getClassName(menu.getClass()));
		this.getMenuRegistery().open(this, menu);
	}

	private String getClassName(Class<?> clazz) {
		return this.getClass().getName()
				.split(Pattern.quote("."))[this.getClass().getName().split(Pattern.quote(".")).length - 1];
	}

	public boolean onClick(InventoryClickEvent event) {
		return true;
	}

	public void onClose(InventoryCloseEvent event) {
	}

	public String getTitle() {
		return title;
	}

	public int getSize() {
		return size;
	}

	public APBuy getPlugin() {
		return plugin;
	}

	public Menu getPrevMenu() {
		return prevMenu;
	}

	public Player getViewer() {
		return viewer;
	}

	public MenuRegistery getMenuRegistery() {
		return menuRegistery;
	}

	public boolean isIgnoreClose() {
		return ignoreClose;
	}

	public void setIgnoreClose(boolean ignoreClose) {
		this.ignoreClose = ignoreClose;
	}

}

MenuRegistery.java

package ap.apbuy.menu;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.event.inventory.InventoryCloseEvent;

import ap.apbuy.APBuy;

public class MenuRegistery implements Listener {

	private List<Menu> openedMenus;
	private APBuy plugin;

	public MenuRegistery(APBuy plugin) {
		this.openedMenus = new ArrayList<>();
		this.plugin = plugin;
	}

	public void open(Menu menu, Menu menuToOpen) {
		if (menu != null) {
			openedMenus.remove(menu);
		}
		menuToOpen.open();
		openedMenus.add(menuToOpen);
	}

	public void forceClose(Player player) {
		this.remove(player);
		player.closeInventory();
	}

	public void close(Player player) {
		player.closeInventory();
	}

	public void remove(Player player) {
		Iterator<Menu> menus = openedMenus.iterator();
		while (menus.hasNext()) {
			if (menus.next().getViewer().equals(player)) {
				menus.remove();
				break;
			}
		}
	}

	public void remove(Menu menu) {
		this.openedMenus.remove(menu);
	}

	public APBuy getPlugin() {
		return plugin;
	}

	@EventHandler
	public void onClose(InventoryCloseEvent event) {
		Menu menu = this.getMenuByPlayer((Player) event.getPlayer());
		if (menu != null) {
			menu.onClose(event);
			this.remove(menu);
		}
		System.out.println(openedMenus.size());
	}

	@EventHandler
	public void onClick(InventoryClickEvent event) {
		Menu menu = this.getMenuByPlayer((Player) event.getWhoClicked());
		if (menu != null) {
			event.setCancelled(menu.onClick(event));
		}
	}

	public Menu getMenuByPlayer(Player player) {
		for (Menu menu : openedMenus) {
			if (menu.getViewer().equals(player)) {
				return menu;
			}
		}
		return null;
	}

}

OneMenu.java

package ap.apbuy.menu.menus.market;

import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;

import ap.apbuy.menu.Menu;
import ap.apbuy.menu.MenuRegistery;
import ap.apbuy.utils.Data;
import ap.apbuy.utils.InventoryBuilder;
import ap.apbuy.utils.ItemStackBuilder;

public class OneMenu extends Menu {

	public OneMenu(Player viewer, MenuRegistery registery) {
		super(viewer, "§0§lA§3§lP§r§8Buy", 54, registery);
	}
	
	public OneMenu(Player viewer, Menu prevMenu) {
		super(viewer, "§0§lA§3§lP§r§8Buy", 54, prevMenu);
	}

	@Override
	public Inventory assembleInventory(Inventory inventory) {
		return new InventoryBuilder(inventory).fillWithItemStack(Data.getGlassGrey()).setItem(4, new ItemStackBuilder("§3§lMy Market", Material.BARRIER).addLineToLore("Here == Your market.").build()).build();
	}
	
	@Override
	public boolean onClick(InventoryClickEvent event) {
		if(event.getSlot() == 49) {
			this.open(new TestOtherMenu(this.getViewer(), this));
		}
		return true;
	}

}

TestOtherMenu.java

package ap.apbuy.menu.menus.market;

import org.bukkit.Material;
import org.bukkit.entity.Player;
import org.bukkit.event.inventory.InventoryClickEvent;
import org.bukkit.inventory.Inventory;
import org.bukkit.inventory.ItemStack;

import ap.apbuy.menu.Menu;
import ap.apbuy.utils.Data;
import ap.apbuy.utils.InventoryBuilder;

public class TestOtherMenu extends Menu {

	public TestOtherMenu(Player viewer, Menu prevMenu) {
		super(viewer, "Test", 54, prevMenu);
	}

	@Override
	public Inventory assembleInventory(Inventory inventory) {
		return new InventoryBuilder(inventory).fillWithItemStack(Data.getGlassGrey())
				.setItem(49, new ItemStack(Material.BARRIER)).build();
	}

	@Override
	public boolean onClick(InventoryClickEvent event) {
		if (event.getSlot() == 49) {
			this.open(this.getPrevMenu());
		}
		return true;
	}

}