Re-add teleport listener and few minor changes

src/main/java/de/epiceric/shopchest/listeners/ShopUpdateListener.java

@@ -1,10 +1,16 @@
 package de.epiceric.shopchest.listeners;
 
 import de.epiceric.shopchest.ShopChest;
+import de.epiceric.shopchest.shop.Shop;
 import de.epiceric.shopchest.utils.Callback;
+import org.bukkit.Location;
+import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerTeleportEvent;
 import org.bukkit.event.world.WorldLoadEvent;
+import org.bukkit.scheduler.BukkitRunnable;
 
 public class ShopUpdateListener implements Listener {
 
@@ -14,6 +20,41 @@ public class ShopUpdateListener implements Listener {
         this.plugin = plugin;
     }
 
+    @EventHandler(priority = EventPriority.MONITOR, ignoreCancelled = true)
+    public void onPlayerTeleport(PlayerTeleportEvent e) {
+        Location from = e.getFrom();
+        Location to = e.getTo();
+        final Player p = e.getPlayer();
+
+        // Wait till the chunk should have loaded on the client
+        // Update IF worlds are different OR chunks are different (as many teleports are in same chunk)
+        if (!from.getWorld().equals(to.getWorld())
+                || from.getChunk().getX() != to.getChunk().getX()
+                || from.getChunk().getZ() != to.getChunk().getZ()) {
+            // Wait for 15 ticks before we actually put it in the queue
+            new BukkitRunnable() {
+                @Override
+                public void run() {
+                    plugin.getUpdater().beforeNext(new Runnable() {
+                        @Override
+                        public void run() {
+                            if (p.isOnline()) {
+                                for (Shop shop : plugin.getShopUtils().getShops()) {
+                                    if (shop.getItem() != null) {
+                                        shop.getItem().setVisible(p, false);
+                                    }
+                                    if (shop.getHologram() != null) {
+                                        shop.getHologram().hidePlayer(p);
+                                    }
+                                }
+                            }
+                        }
+                    });
+                }
+            }.runTaskLater(plugin, 15L);
+        }
+    }
+
     @EventHandler
     public void onWorldLoad(WorldLoadEvent e) {
         final String worldName = e.getWorld().getName();

src/main/java/de/epiceric/shopchest/nms/Hologram.java

@@ -10,18 +10,20 @@ import org.bukkit.entity.Player;
 import org.bukkit.scheduler.BukkitRunnable;
 
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class Hologram {
 
     private static List<Hologram> holograms = new ArrayList<>();
 
+    private final Set<UUID> visibility = Collections.newSetFromMap(new ConcurrentHashMap<UUID, Boolean>());
+    private final List<ArmorStandWrapper> wrappers = new ArrayList<>();
+    private final Location location;
+    private final ShopChest plugin;
+    private final Config config;
+
     private boolean exists = false;
-    private List<ArmorStandWrapper> wrappers = new ArrayList<>();
     private ArmorStandWrapper interactArmorStandWrapper;
-    private Location location;
-    private Set<UUID> visibility = new HashSet<>();
-    private ShopChest plugin;
-    private Config config;
 
     public Hologram(ShopChest plugin, String[] lines, Location location) {
         this.plugin = plugin;
@@ -254,7 +256,9 @@ public class Hologram {
      */
     public static Hologram getHologram(ArmorStand armorStand) {
         for (Hologram hologram : holograms) {
-            if (hologram.contains(armorStand)) return hologram;
+            if (hologram.contains(armorStand)) {
+                return hologram;
+            }
         }
 
         return null;
@@ -265,12 +269,7 @@ public class Hologram {
      * @return Whether the armor stand is part of a hologram
      */
     public static boolean isPartOfHologram(ArmorStand armorStand) {
-        for (Hologram hologram : holograms) {
+        return getHologram(armorStand) != null;
-            if (hologram.contains(armorStand)) {
-                return true;
-            }
-        }
-        return false;
     }
 
 }

src/main/java/de/epiceric/shopchest/shop/ShopItem.java

@@ -10,16 +10,17 @@ import org.bukkit.inventory.ItemStack;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
-import java.util.HashSet;
+import java.util.Collections;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class ShopItem {
 
-    private ShopChest plugin;
+    private final ShopChest plugin;
-    private Set<UUID> visibility = new HashSet<>();
+    private final Set<UUID> visibility = Collections.newSetFromMap(new ConcurrentHashMap<UUID, Boolean>());
-    private ItemStack itemStack;
+    private final ItemStack itemStack;
-    private Location location;
+    private final Location location;
 
     private Object entityItem;
     private int entityId;

src/main/java/de/epiceric/shopchest/utils/ShopUpdater.java

@@ -5,6 +5,9 @@ import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.bukkit.scheduler.BukkitTask;
 
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
 public class ShopUpdater {
 
     public enum UpdateQuality {
@@ -28,8 +31,7 @@ public class ShopUpdater {
     }
 
     private final ShopChest plugin;
-
+    private final Queue<Runnable> beforeNext = new ConcurrentLinkedQueue<>();
-    private long interval = UpdateQuality.NORMAL.getInterval();
 
     private volatile BukkitTask running;
 
@@ -42,8 +44,8 @@ public class ShopUpdater {
      */
     public void start() {
         if (!isRunning()) {
-            interval = plugin.getShopChestConfig().update_quality.getInterval();
+            long interval = plugin.getShopChestConfig().update_quality.getInterval();
-            running = Bukkit.getScheduler().runTaskTimerAsynchronously(plugin, new ShopUpdaterTask(plugin), interval, interval);
+            running = Bukkit.getScheduler().runTaskTimerAsynchronously(plugin, new ShopUpdaterTask(), interval, interval);
         }
     }
 
@@ -72,16 +74,26 @@ public class ShopUpdater {
         return running != null;
     }
 
-    private static class ShopUpdaterTask implements Runnable {
+    /**
-
+     * Register a task to run before next loop
-        private final ShopChest plugin;
+     *
-
+     * @param runnable task to run
-        private ShopUpdaterTask(ShopChest plugin) {
+     */
-            this.plugin = plugin;
+    public void beforeNext(Runnable runnable) {
+        beforeNext.add(runnable);
     }
 
+    private class ShopUpdaterTask implements Runnable {
+
         @Override
         public void run() {
+            if (!beforeNext.isEmpty()) {
+                for (Runnable runnable : beforeNext) {
+                    runnable.run();
+                }
+                beforeNext.clear();
+            }
+
             for (Player p : Bukkit.getOnlinePlayers()) {
                 plugin.getShopUtils().updateShops(p);
             }

src/main/java/de/epiceric/shopchest/utils/ShopUtils.java

@@ -13,16 +13,13 @@ import org.bukkit.inventory.InventoryHolder;
 import org.bukkit.permissions.PermissionAttachmentInfo;
 import org.bukkit.util.Vector;
 
-import java.util.Collection;
+import java.util.*;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Set;
 
 public class ShopUtils {
 
-    private HashMap<Location, Shop> shopLocation = new HashMap<>();
+    private final HashMap<Location, Shop> shopLocation = new HashMap<>();
-    private HashMap<Player, Location> playerLocation = new HashMap<>();
+    private final HashMap<UUID, Location> playerLocation = new HashMap<>();
-    private ShopChest plugin;
+    private final ShopChest plugin;
 
     public ShopUtils(ShopChest plugin) {
         this.plugin = plugin;
@@ -55,8 +52,7 @@ public class ShopUtils {
      * @return Array of all Shops
      */
     public Shop[] getShops() {
-        Collection<Shop> shops = shopLocation.values();
+        return shopLocation.values().toArray(new Shop[0]);
-        return shops.toArray(new Shop[shops.size()]);
     }
 
     /**
@@ -274,7 +270,7 @@ public class ShopUtils {
      * @param force Whether update should be forced even if player has not moved
      */
     public void updateShops(Player player, boolean force) {
-        if (!force && player.getLocation().equals(playerLocation.get(player))) {
+        if (!force && player.getLocation().equals(playerLocation.get(player.getUniqueId()))) {
             // Player has not moved, so don't calculate shops again.
             return;
         }
@@ -314,7 +310,7 @@ public class ShopUtils {
             updateNearestShops(player);
         }
 
-        playerLocation.put(player, player.getLocation());
+        playerLocation.put(player.getUniqueId(), player.getLocation());
     }
 
     private Set<Shop> getShopsInSight(Player player) {