Implement new event

main/src/main/java/net/citizensnpcs/Metrics.java

@@ -40,7 +40,6 @@ import org.bukkit.plugin.java.JavaPlugin;
  * <p>
  * Check out https://bStats.org/ to learn more about bStats!
  */
-@SuppressWarnings({ "WeakerAccess", "unused" })
 
 public class Metrics {
 

main/src/main/java/net/citizensnpcs/commands/NPCCommands.java

@@ -2519,7 +2519,7 @@ public class NPCCommands {
 
     @Command(
             aliases = { "npc" },
-            usage = "rotate (--body [yaw]) (--head [yaw]) (--pitch [pitch]) (-s(mooth))",
+            usage = "rotate (--towards [x,y,z]) (--body [yaw]) (--head [yaw]) (--pitch [pitch]) (-s(mooth))",
             desc = "Rotate NPC",
             flags = "s",
             modifiers = { "rotate" },
@@ -2527,7 +2527,7 @@ public class NPCCommands {
             max = 1,
             permission = "citizens.npc.rotate")
     public void rotate(CommandContext args, CommandSender sender, NPC npc, @Flag("body") Float yaw,
-            @Flag("head") Float head, @Flag("pitch") Float pitch) {
+            @Flag("head") Float head, @Flag("pitch") Float pitch, @Flag("towards") Location towards) {
         if (args.hasFlag('s')) {
             if (pitch == null) {
                 pitch = npc.getStoredLocation().getPitch();
@@ -2542,6 +2542,10 @@ public class NPCCommands {
             npc.getOrAddTrait(RotationTrait.class).getPhysicalSession().rotateToHave(yaw, pitch);
             return;
         }
+        if (towards != null) {
+            npc.getOrAddTrait(RotationTrait.class).getPhysicalSession().rotateToFace(towards);
+            return;
+        }
         if (yaw != null) {
             NMS.setBodyYaw(npc.getEntity(), yaw);
             if (npc.getEntity().getType() == EntityType.PLAYER) {

main/src/main/java/net/citizensnpcs/npc/CitizensNPC.java

@@ -196,8 +196,7 @@ public class CitizensNPC extends AbstractNPC {
 
     @Override
     public boolean requiresNameHologram() {
-        return super.requiresNameHologram()
+        return super.requiresNameHologram() || Setting.ALWAYS_USE_NAME_HOLOGRAM.asBoolean();
-                || Setting.ALWAYS_USE_NAME_HOLOGRAM.asBoolean() && !data().has(NPC.Metadata.HOLOGRAM_FOR);
     }
 
     private void resetCachedCoord() {

main/src/main/java/net/citizensnpcs/trait/HologramTrait.java

@@ -110,10 +110,10 @@ public class HologramTrait extends Trait {
             hologramNPC = registry.createNPC(EntityType.ARMOR_STAND, line);
             hologramNPC.getOrAddTrait(ArmorStandTrait.class).setAsHelperEntityWithName(npc);
         }
+        hologramNPC.data().set(NPC.Metadata.HOLOGRAM_FOR, npc.getUniqueId().toString());
         if (Setting.PACKET_HOLOGRAMS.asBoolean()) {
             hologramNPC.addTrait(PacketNPC.class);
         }
-        hologramNPC.data().set(NPC.Metadata.HOLOGRAM_FOR, npc.getUniqueId().toString());
         if (viewRange != -1) {
             hologramNPC.data().set(NPC.Metadata.TRACKING_RANGE, viewRange);
         }

main/src/main/java/net/citizensnpcs/trait/text/TextBasePrompt.java

@@ -28,6 +28,7 @@ public class TextBasePrompt extends StringPrompt {
         String input = parts[0];
 
         CommandSender sender = (CommandSender) context.getForWhom();
+        Messaging.send(sender, getPromptText(context));
         if (input.equalsIgnoreCase("add")) {
             text.add(Joiner.on(' ').join(Arrays.copyOfRange(parts, 1, parts.length)));
             return this;
@@ -59,10 +60,7 @@ public class TextBasePrompt extends StringPrompt {
             } catch (NumberFormatException e) {
                 Messaging.sendErrorTr(sender, Messages.TEXT_EDITOR_INVALID_PAGE);
             }
-        }
+        } else if (input.equalsIgnoreCase("delay")) {
-        Messaging.send(sender, getPromptText(context));
-
-        if (input.equalsIgnoreCase("delay")) {
             try {
                 int delay = Integer.parseInt(parts[1]);
                 text.setDelay(delay);

main/src/main/java/net/citizensnpcs/trait/versioned/BossBarTrait.java

@@ -38,7 +38,7 @@ import net.citizensnpcs.util.Util;
 
 @TraitName("bossbar")
 public class BossBarTrait extends Trait {
-    private BossBar barCache;
+    private BossBar activeBar;
     @Persist
     private BarColor color = BarColor.PURPLE;
     @Persist
@@ -65,11 +65,11 @@ public class BossBarTrait extends Trait {
         if (npc.isSpawned() && isBoss(npc.getEntity()) && NMS.getBossBar(npc.getEntity()) != null)
             return (BossBar) NMS.getBossBar(npc.getEntity());
 
-        if (barCache == null) {
+        if (activeBar == null) {
-            barCache = Bukkit.getServer().createBossBar(npc.getFullName(), color, style,
+            activeBar = Bukkit.getServer().createBossBar(npc.getFullName(), color, style,
                     flags.toArray(new BarFlag[flags.size()]));
         }
-        return barCache;
+        return activeBar;
     }
 
     public BarColor getColor() {
@@ -114,12 +114,12 @@ public class BossBarTrait extends Trait {
 
     @Override
     public void onDespawn() {
-        if (barCache == null)
+        if (activeBar == null)
             return;
 
-        barCache.removeAll();
+        activeBar.removeAll();
-        barCache.hide();
+        activeBar.hide();
-        barCache = null;
+        activeBar = null;
     }
 
     @Override

main/src/main/java/net/citizensnpcs/trait/versioned/CamelTrait.java

@@ -26,6 +26,10 @@ public class CamelTrait extends Trait {
         super("cameltrait");
     }
 
+    public CamelPose getPose() {
+        return pose;
+    }
+
     @Override
     public void run() {
         if (npc.isSpawned() && npc.getEntity() instanceof Camel) {

main/src/main/java/net/citizensnpcs/util/NMS.java

@@ -145,15 +145,15 @@ public class NMS {
         BRIDGE.cancelMoveDestination(entity);
     }
 
+    public static Iterable<Object> createBundlePacket(List<Object> packets) {
+        return BRIDGE.createBundlePacket(packets);
+    }
+
     /*
      * Yggdrasil's default implementation of this method silently fails instead of throwing
      * an Exception like it should.
      */
 
-    public static Iterable<Object> createBundlePacket(List<Object> packets) {
-        return BRIDGE.createBundlePacket(packets);
-    }
-
     public static EntityPacketTracker createPacketTracker(Entity entity) {
         return createPacketTracker(entity, new PacketAggregator());
     }
@@ -601,6 +601,10 @@ public class NMS {
         return BRIDGE.getVerticalMovement(bukkitEntity);
     }
 
+    public static Collection<Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        return BRIDGE.getViewingPlayers(entity);
+    }
+
     public static double getWidth(Entity entity) {
         return BRIDGE.getWidth(entity);
     }

main/src/main/java/net/citizensnpcs/util/NMSBridge.java

@@ -116,6 +116,10 @@ public interface NMSBridge {
 
     public float getVerticalMovement(Entity entity);
 
+    public default Collection<Player> getViewingPlayers(Entity entity) {
+        return ((Player) entity).getTrackedBy();
+    }
+
     public double getWidth(Entity entity);
 
     public float getYaw(Entity entity);

main/src/main/java/net/citizensnpcs/util/PlayerUpdateTask.java

@@ -43,6 +43,7 @@ public class PlayerUpdateTask extends BukkitRunnable {
                 PLAYERS.put(entity.getUniqueId(), new PlayerTick((Player) entity));
             }
         }
+        // convert to sorted list with binary search
         PLAYERS_PENDING_ADD.clear();
         PLAYERS_PENDING_REMOVE.clear();
 

v1_10_R1/src/main/java/net/citizensnpcs/nms/v1_10_R1/util/NMSImpl.java

@@ -702,6 +702,13 @@ public class NMSImpl implements NMSBridge {
         return handle.bf;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTrackerEntry entry = server.getTracker().trackedEntities.get(entity.getEntityId());
+        return PlayerlistTrackerEntry.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return getHandle(entity).width;

v1_10_R1/src/main/java/net/citizensnpcs/nms/v1_10_R1/util/PlayerlistTrackerEntry.java

@@ -1,6 +1,8 @@
 package net.citizensnpcs.nms.v1_10_R1.util;
 
 import java.lang.reflect.Field;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 import org.bukkit.entity.EntityType;
@@ -96,6 +98,10 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
         return 0;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTrackerEntry tracker) {
+        return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+    }
+
     private static Entity getTracker(EntityTrackerEntry entry) {
         try {
             return (Entity) TRACKER.get(entry);

v1_11_R1/src/main/java/net/citizensnpcs/nms/v1_11_R1/util/NMSImpl.java

@@ -738,6 +738,13 @@ public class NMSImpl implements NMSBridge {
         return handle.be;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTrackerEntry entry = server.getTracker().trackedEntities.get(entity.getEntityId());
+        return PlayerlistTrackerEntry.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return getHandle(entity).width;

v1_11_R1/src/main/java/net/citizensnpcs/nms/v1_11_R1/util/PlayerlistTrackerEntry.java

@@ -4,6 +4,7 @@ import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -12,6 +13,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
 import net.citizensnpcs.util.NMS;
@@ -44,6 +46,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -65,6 +77,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -138,6 +160,20 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
         return 0;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTrackerEntry tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTrackerEntry entry) {
         try {
             return (Entity) TRACKER.get(entry);

v1_12_R1/src/main/java/net/citizensnpcs/nms/v1_12_R1/util/NMSImpl.java

@@ -744,6 +744,13 @@ public class NMSImpl implements NMSBridge {
         return handle.be;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTrackerEntry entry = server.getTracker().trackedEntities.get(entity.getEntityId());
+        return PlayerlistTrackerEntry.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_12_R1/src/main/java/net/citizensnpcs/nms/v1_12_R1/util/PlayerlistTrackerEntry.java

@@ -4,6 +4,7 @@ import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -12,6 +13,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_12_R1.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -45,6 +47,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -66,6 +78,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -147,6 +169,20 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
         return 0;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTrackerEntry tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTrackerEntry entry) {
         try {
             return (Entity) TRACKER.get(entry);

v1_13_R2/src/main/java/net/citizensnpcs/nms/v1_13_R2/util/NMSImpl.java

@@ -767,6 +767,13 @@ public class NMSImpl implements NMSBridge {
         return handle.bh;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTrackerEntry entry = server.getTracker().trackedEntities.get(entity.getEntityId());
+        return PlayerlistTrackerEntry.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_13_R2/src/main/java/net/citizensnpcs/nms/v1_13_R2/util/PlayerlistTrackerEntry.java

@@ -4,6 +4,7 @@ import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -12,6 +13,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_13_R2.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -45,6 +47,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -66,6 +78,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -146,6 +168,20 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
         return 0;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTrackerEntry tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTrackerEntry entry) {
         try {
             return (Entity) TRACKER.get(entry);

v1_14_R1/src/main/java/net/citizensnpcs/nms/v1_14_R1/util/NMSImpl.java

@@ -818,6 +818,13 @@ public class NMSImpl implements NMSBridge {
         return handle.bb;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTracker entry = server.getChunkProvider().playerChunkMap.trackedEntities.get(entity.getEntityId());
+        return PlayerlistTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_14_R1/src/main/java/net/citizensnpcs/nms/v1_14_R1/util/PlayerlistTracker.java

@@ -3,6 +3,7 @@ package net.citizensnpcs.nms.v1_14_R1.util;
 import java.lang.invoke.MethodHandle;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -11,6 +12,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_14_R1.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -46,6 +48,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -67,6 +79,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -133,6 +155,20 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
         return false;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTracker tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTracker entry) {
         try {
             return (Entity) TRACKER.invoke(entry);

v1_15_R1/src/main/java/net/citizensnpcs/nms/v1_15_R1/util/NMSImpl.java

@@ -833,6 +833,13 @@ public class NMSImpl implements NMSBridge {
         return handle.aZ;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTracker entry = server.getChunkProvider().playerChunkMap.trackedEntities.get(entity.getEntityId());
+        return PlayerlistTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_15_R1/src/main/java/net/citizensnpcs/nms/v1_15_R1/util/PlayerlistTracker.java

@@ -3,6 +3,7 @@ package net.citizensnpcs.nms.v1_15_R1.util;
 import java.lang.invoke.MethodHandle;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -11,6 +12,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_15_R1.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -46,6 +48,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -67,6 +79,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -133,6 +155,20 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
         return false;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTracker tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTracker entry) {
         try {
             return (Entity) TRACKER.invoke(entry);

v1_16_R3/src/main/java/net/citizensnpcs/nms/v1_16_R3/util/NMSImpl.java

@@ -857,6 +857,13 @@ public class NMSImpl implements NMSBridge {
         return handle.aR;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTracker entry = server.getChunkProvider().playerChunkMap.trackedEntities.get(entity.getEntityId());
+        return PlayerlistTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_16_R3/src/main/java/net/citizensnpcs/nms/v1_16_R3/util/PlayerlistTracker.java

@@ -3,6 +3,7 @@ package net.citizensnpcs.nms.v1_16_R3.util;
 import java.lang.invoke.MethodHandle;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -11,6 +12,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_16_R3.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -46,6 +48,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -67,6 +79,16 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -133,6 +155,20 @@ public class PlayerlistTracker extends PlayerChunkMap.EntityTracker {
         return false;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTracker tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static Entity getTracker(EntityTracker entry) {
         try {
             return (Entity) TRACKER.invoke(entry);

v1_17_R1/src/main/java/net/citizensnpcs/nms/v1_17_R1/entity/EntityHumanNPC.java

@@ -40,7 +40,6 @@ import net.citizensnpcs.util.Util;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TextComponent;
-import net.minecraft.network.protocol.Packet;
 import net.minecraft.network.protocol.PacketFlow;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
@@ -160,14 +159,6 @@ public class EntityHumanNPC extends ServerPlayer implements NPCHolder, Skinnable
         }
     }
 
-    @Override
-    public Packet<?> getAddEntityPacket() {
-        if (playerlistTracker != null) {
-            playerlistTracker.updateLastPlayer();
-        }
-        return super.getAddEntityPacket();
-    }
-
     @Override
     public MobAI getAI() {
         return ai;

v1_17_R1/src/main/java/net/citizensnpcs/nms/v1_17_R1/util/NMSImpl.java

@@ -860,6 +860,13 @@ public class NMSImpl implements NMSBridge {
         return handle.xxa;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        ServerLevel server = (ServerLevel) getHandle(entity).level;
+        TrackedEntity entry = server.getChunkProvider().chunkMap.G.get(entity.getEntityId());
+        return PlayerlistTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_17_R1/src/main/java/net/citizensnpcs/nms/v1_17_R1/util/PlayerlistTracker.java

@@ -1,11 +1,17 @@
 package net.citizensnpcs.nms.v1_17_R1.util;
 
 import java.lang.invoke.MethodHandle;
+import java.util.Collection;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
+import com.google.common.collect.ForwardingSet;
+
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_17_R1.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -15,29 +21,52 @@ import net.minecraft.server.level.ChunkMap;
 import net.minecraft.server.level.ChunkMap.TrackedEntity;
 import net.minecraft.server.level.ServerEntity;
 import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerPlayerConnection;
 import net.minecraft.world.entity.Entity;
 
 public class PlayerlistTracker extends ChunkMap.TrackedEntity {
-    private ServerPlayer lastUpdatedPlayer;
     private final Entity tracker;
 
     public PlayerlistTracker(ChunkMap map, Entity entity, int i, int j, boolean flag) {
         map.super(entity, i, j, flag);
         this.tracker = entity;
+        try {
+            Set<ServerPlayerConnection> set = (Set<ServerPlayerConnection>) TRACKING_SET_GETTER.invoke(this);
+            TRACKING_SET_SETTER.invoke(this, new ForwardingSet<ServerPlayerConnection>() {
+                @Override
+                public boolean add(ServerPlayerConnection conn) {
+                    boolean res = super.add(conn);
+                    if (res) {
+                        Bukkit.getPluginManager().callEvent(new NPCLinkToPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                conn.getPlayer().getBukkitEntity()));
+                    }
+                    return res;
+                }
+
+                @Override
+                protected Set<ServerPlayerConnection> delegate() {
+                    return set;
+                }
+
+                @Override
+                public boolean remove(Object conn) {
+                    boolean removed = super.remove(conn);
+                    if (removed) {
+                        Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                ((ServerPlayerConnection) conn).getPlayer().getBukkitEntity()));
+                    }
+                    return removed;
+                }
+            });
+        } catch (Throwable e) {
+            e.printStackTrace();
+        }
     }
 
     public PlayerlistTracker(ChunkMap map, TrackedEntity entry) {
         this(map, getTracker(entry), getTrackingDistance(entry), getE(entry), getF(entry));
     }
 
-    public void updateLastPlayer() {
-        if (lastUpdatedPlayer != null) {
-            Bukkit.getPluginManager().callEvent(
-                    new NPCLinkToPlayerEvent(((NPCHolder) tracker).getNPC(), lastUpdatedPlayer.getBukkitEntity()));
-            lastUpdatedPlayer = null;
-        }
-    }
-
     @Override
     public void updatePlayer(final ServerPlayer entityplayer) {
         if (entityplayer instanceof EntityHumanNPC)
@@ -74,7 +103,6 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
             if (cancelled)
                 return;
         }
-        this.lastUpdatedPlayer = entityplayer;
         super.updatePlayer(entityplayer);
     }
 
@@ -96,6 +124,10 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
         return false;
     }
 
+    public static Collection<org.bukkit.entity.Player> getSeenBy(TrackedEntity tracker) {
+        return tracker.seenBy.stream().map(c -> c.getPlayer().getBukkitEntity()).collect(Collectors.toSet());
+    }
+
     private static Entity getTracker(TrackedEntity entry) {
         try {
             return (Entity) TRACKER.invoke(entry);
@@ -116,9 +148,11 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
 
     private static final MethodHandle E = NMS.getGetter(ServerEntity.class, "e");
     private static final MethodHandle F = NMS.getGetter(ServerEntity.class, "f");
-    private static volatile Boolean REQUIRES_SYNC;
+    private static volatile Boolean REQUIRES_SYNC = false;
     private static final MethodHandle TRACKER = NMS.getFirstGetter(TrackedEntity.class, Entity.class);
     private static final MethodHandle TRACKER_ENTRY = NMS.getFirstGetter(TrackedEntity.class, ServerEntity.class);
     private static final MethodHandle TRACKING_RANGE = NMS.getFirstGetter(TrackedEntity.class, int.class);
     private static final MethodHandle TRACKING_RANGE_SETTER = NMS.getFirstFinalSetter(TrackedEntity.class, int.class);
+    private static final MethodHandle TRACKING_SET_GETTER = NMS.getFirstGetter(TrackedEntity.class, Set.class);
+    private static final MethodHandle TRACKING_SET_SETTER = NMS.getFirstFinalSetter(TrackedEntity.class, Set.class);
 }

v1_18_R2/src/main/java/net/citizensnpcs/nms/v1_18_R2/entity/EntityHumanNPC.java

@@ -41,7 +41,6 @@ import net.citizensnpcs.util.Util;
 import net.minecraft.core.BlockPos;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.TextComponent;
-import net.minecraft.network.protocol.Packet;
 import net.minecraft.network.protocol.PacketFlow;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ServerLevel;
@@ -161,14 +160,6 @@ public class EntityHumanNPC extends ServerPlayer implements NPCHolder, Skinnable
         }
     }
 
-    @Override
-    public Packet<?> getAddEntityPacket() {
-        if (playerlistTracker != null) {
-            playerlistTracker.updateLastPlayer();
-        }
-        return super.getAddEntityPacket();
-    }
-
     @Override
     public MobAI getAI() {
         return ai;

v1_18_R2/src/main/java/net/citizensnpcs/nms/v1_18_R2/util/NMSImpl.java

@@ -867,6 +867,13 @@ public class NMSImpl implements NMSBridge {
         return handle.xxa;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        ServerLevel server = (ServerLevel) getHandle(entity).level;
+        TrackedEntity entry = server.getChunkSource().chunkMap.entityMap.get(entity.getEntityId());
+        return PlayerlistTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_18_R2/src/main/java/net/citizensnpcs/nms/v1_18_R2/util/PlayerlistTracker.java

@@ -1,11 +1,17 @@
 package net.citizensnpcs.nms.v1_18_R2.util;
 
 import java.lang.invoke.MethodHandle;
+import java.util.Collection;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
+import com.google.common.collect.ForwardingSet;
+
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_18_R2.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -15,29 +21,52 @@ import net.minecraft.server.level.ChunkMap;
 import net.minecraft.server.level.ChunkMap.TrackedEntity;
 import net.minecraft.server.level.ServerEntity;
 import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.network.ServerPlayerConnection;
 import net.minecraft.world.entity.Entity;
 
 public class PlayerlistTracker extends ChunkMap.TrackedEntity {
-    private ServerPlayer lastUpdatedPlayer;
     private final Entity tracker;
 
     public PlayerlistTracker(ChunkMap map, Entity entity, int i, int j, boolean flag) {
         map.super(entity, i, j, flag);
         this.tracker = entity;
+        try {
+            Set<ServerPlayerConnection> set = (Set<ServerPlayerConnection>) TRACKING_SET_GETTER.invoke(this);
+            TRACKING_SET_SETTER.invoke(this, new ForwardingSet<ServerPlayerConnection>() {
+                @Override
+                public boolean add(ServerPlayerConnection conn) {
+                    boolean res = super.add(conn);
+                    if (res) {
+                        Bukkit.getPluginManager().callEvent(new NPCLinkToPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                conn.getPlayer().getBukkitEntity()));
+                    }
+                    return res;
+                }
+
+                @Override
+                protected Set<ServerPlayerConnection> delegate() {
+                    return set;
+                }
+
+                @Override
+                public boolean remove(Object conn) {
+                    boolean removed = super.remove(conn);
+                    if (removed) {
+                        Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                ((ServerPlayerConnection) conn).getPlayer().getBukkitEntity()));
+                    }
+                    return removed;
+                }
+            });
+        } catch (Throwable e) {
+            e.printStackTrace();
+        }
     }
 
     public PlayerlistTracker(ChunkMap map, TrackedEntity entry) {
         this(map, getTracker(entry), getTrackingDistance(entry), getE(entry), getF(entry));
     }
 
-    public void updateLastPlayer() {
-        if (lastUpdatedPlayer != null) {
-            Bukkit.getPluginManager().callEvent(
-                    new NPCLinkToPlayerEvent(((NPCHolder) tracker).getNPC(), lastUpdatedPlayer.getBukkitEntity()));
-            lastUpdatedPlayer = null;
-        }
-    }
-
     @Override
     public void updatePlayer(final ServerPlayer entityplayer) {
         if (entityplayer instanceof EntityHumanNPC)
@@ -74,7 +103,6 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
             if (cancelled)
                 return;
         }
-        this.lastUpdatedPlayer = entityplayer;
         super.updatePlayer(entityplayer);
     }
 
@@ -96,6 +124,10 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
         return false;
     }
 
+    public static Collection<org.bukkit.entity.Player> getSeenBy(TrackedEntity tracker) {
+        return tracker.seenBy.stream().map(c -> c.getPlayer().getBukkitEntity()).collect(Collectors.toSet());
+    }
+
     private static Entity getTracker(TrackedEntity entry) {
         try {
             return (Entity) TRACKER.invoke(entry);
@@ -116,9 +148,11 @@ public class PlayerlistTracker extends ChunkMap.TrackedEntity {
 
     private static final MethodHandle E = NMS.getGetter(ServerEntity.class, "e");
     private static final MethodHandle F = NMS.getGetter(ServerEntity.class, "f");
-    private static volatile Boolean REQUIRES_SYNC;
+    private static volatile Boolean REQUIRES_SYNC = false;
     private static final MethodHandle TRACKER = NMS.getFirstGetter(TrackedEntity.class, Entity.class);
     private static final MethodHandle TRACKER_ENTRY = NMS.getFirstGetter(TrackedEntity.class, ServerEntity.class);
     private static final MethodHandle TRACKING_RANGE = NMS.getFirstGetter(TrackedEntity.class, int.class);
     private static final MethodHandle TRACKING_RANGE_SETTER = NMS.getFirstFinalSetter(TrackedEntity.class, int.class);
+    private static final MethodHandle TRACKING_SET_GETTER = NMS.getFirstGetter(TrackedEntity.class, Set.class);
+    private static final MethodHandle TRACKING_SET_SETTER = NMS.getFirstFinalSetter(TrackedEntity.class, Set.class);
 }

v1_19_R3/src/main/java/net/citizensnpcs/nms/v1_19_R3/util/CitizensEntityTracker.java

@@ -1,7 +1,9 @@
 package net.citizensnpcs.nms.v1_19_R3.util;
 
 import java.lang.invoke.MethodHandle;
+import java.util.Collection;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -9,6 +11,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_19_R3.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -44,6 +47,16 @@ public class CitizensEntityTracker extends ChunkMap.TrackedEntity {
                 protected Set<ServerPlayerConnection> delegate() {
                     return set;
                 }
+
+                @Override
+                public boolean remove(Object conn) {
+                    boolean removed = super.remove(conn);
+                    if (removed) {
+                        Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                ((ServerPlayerConnection) conn).getPlayer().getBukkitEntity()));
+                    }
+                    return removed;
+                }
             });
         } catch (Throwable e) {
             e.printStackTrace();
@@ -111,6 +124,10 @@ public class CitizensEntityTracker extends ChunkMap.TrackedEntity {
         return false;
     }
 
+    public static Collection<org.bukkit.entity.Player> getSeenBy(TrackedEntity tracker) {
+        return tracker.seenBy.stream().map(c -> c.getPlayer().getBukkitEntity()).collect(Collectors.toSet());
+    }
+
     private static Entity getTracker(TrackedEntity entry) {
         try {
             return (Entity) TRACKER.invoke(entry);

v1_19_R3/src/main/java/net/citizensnpcs/nms/v1_19_R3/util/NMSImpl.java

@@ -907,6 +907,13 @@ public class NMSImpl implements NMSBridge {
         return handle.xxa;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        ServerLevel server = (ServerLevel) getHandle(entity).level;
+        TrackedEntity entry = server.getChunkSource().chunkMap.entityMap.get(entity.getEntityId());
+        return CitizensEntityTracker.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return entity.getWidth();

v1_20_R2/src/main/java/net/citizensnpcs/nms/v1_20_R2/util/CitizensEntityTracker.java

@@ -1,7 +1,9 @@
 package net.citizensnpcs.nms.v1_20_R2.util;
 
 import java.lang.invoke.MethodHandle;
+import java.util.Collection;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -9,6 +11,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_20_R2.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -44,6 +47,16 @@ public class CitizensEntityTracker extends ChunkMap.TrackedEntity {
                 protected Set<ServerPlayerConnection> delegate() {
                     return set;
                 }
+
+                @Override
+                public boolean remove(Object conn) {
+                    boolean removed = super.remove(conn);
+                    if (removed) {
+                        Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(((NPCHolder) tracker).getNPC(),
+                                ((ServerPlayerConnection) conn).getPlayer().getBukkitEntity()));
+                    }
+                    return removed;
+                }
             });
         } catch (Throwable e) {
             e.printStackTrace();
@@ -94,6 +107,10 @@ public class CitizensEntityTracker extends ChunkMap.TrackedEntity {
         super.updatePlayer(entityplayer);
     }
 
+    public static Collection<org.bukkit.entity.Entity> getSeenBy(TrackedEntity tracker) {
+        return tracker.seenBy.stream().map(c -> c.getPlayer().getBukkitEntity()).collect(Collectors.toSet());
+    }
+
     private static boolean getTrackDelta(TrackedEntity entry) {
         try {
             return (boolean) TRACK_DELTA.invoke(TRACKER_ENTRY.invoke(entry));

v1_8_R3/src/main/java/net/citizensnpcs/nms/v1_8_R3/util/NMSImpl.java

@@ -646,6 +646,13 @@ public class NMSImpl implements NMSBridge {
         return handle.aZ;
     }
 
+    @Override
+    public Collection<org.bukkit.entity.Player> getViewingPlayers(org.bukkit.entity.Entity entity) {
+        WorldServer server = (WorldServer) NMSImpl.getHandle(entity).getWorld();
+        EntityTrackerEntry entry = server.getTracker().trackedEntities.get(entity.getEntityId());
+        return PlayerlistTrackerEntry.getSeenBy(entry);
+    }
+
     @Override
     public double getWidth(org.bukkit.entity.Entity entity) {
         return getHandle(entity).width;
@@ -1787,9 +1794,7 @@ public class NMSImpl implements NMSBridge {
     private static final Set<EntityType> BAD_CONTROLLER_LOOK = EnumSet.of(EntityType.SILVERFISH, EntityType.ENDERMITE,
             EntityType.ENDER_DRAGON, EntityType.BAT, EntityType.SLIME, EntityType.MAGMA_CUBE, EntityType.HORSE,
             EntityType.GHAST);
-
     private static final float DEFAULT_SPEED = 1F;
-
     public static MethodHandle ENDERDRAGON_CHECK_WALLS = NMS.getFirstMethodHandleWithReturnType(EntityEnderDragon.class,
             true, boolean.class, AxisAlignedBB.class);
     private static Method ENTITY_ATTACK_A = NMS.getMethod(Entity.class, "a", true, EntityLiving.class, Entity.class);

v1_8_R3/src/main/java/net/citizensnpcs/nms/v1_8_R3/util/PlayerlistTrackerEntry.java

@@ -4,6 +4,7 @@ import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.bukkit.Bukkit;
 
@@ -12,6 +13,7 @@ import com.google.common.collect.ForwardingSet;
 
 import net.citizensnpcs.api.event.NPCLinkToPlayerEvent;
 import net.citizensnpcs.api.event.NPCSeenByPlayerEvent;
+import net.citizensnpcs.api.event.NPCUnlinkFromPlayerEvent;
 import net.citizensnpcs.api.npc.NPC;
 import net.citizensnpcs.nms.v1_8_R3.entity.EntityHumanNPC;
 import net.citizensnpcs.npc.ai.NPCHolder;
@@ -43,6 +45,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                         }
                         return res;
                     }
+
+                    @Override
+                    public Boolean remove(Object conn) {
+                        Boolean removed = super.remove(conn);
+                        if (removed == true) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -64,6 +76,16 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
                     protected Set<EntityPlayer> delegate() {
                         return delegate;
                     }
+
+                    @Override
+                    public boolean remove(Object conn) {
+                        boolean removed = super.remove(conn);
+                        if (removed) {
+                            Bukkit.getPluginManager().callEvent(new NPCUnlinkFromPlayerEvent(
+                                    ((NPCHolder) tracker).getNPC(), ((EntityPlayer) conn).getBukkitEntity()));
+                        }
+                        return removed;
+                    }
                 });
             } catch (Throwable e) {
                 e.printStackTrace();
@@ -126,6 +148,20 @@ public class PlayerlistTrackerEntry extends EntityTrackerEntry {
         return 0;
     }
 
+    public static Set<org.bukkit.entity.Player> getSeenBy(EntityTrackerEntry tracker) {
+        if (TRACKING_MAP_GETTER != null) {
+            Map<EntityPlayer, Boolean> delegate;
+            try {
+                delegate = (Map<EntityPlayer, Boolean>) TRACKING_MAP_GETTER.invoke(tracker);
+            } catch (Throwable e) {
+                return null;
+            }
+            return delegate.keySet().stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        } else {
+            return tracker.trackedPlayers.stream().map(p -> p.getBukkitEntity()).collect(Collectors.toSet());
+        }
+    }
+
     private static boolean getU(EntityTrackerEntry entry) {
         try {
             return (Boolean) U.get(entry);