Added 1.7.10 NPC interaction support (for #10).

commons/pom.xml

@@ -16,8 +16,16 @@
         <dependency>
             <groupId>org.spigotmc</groupId>
             <artifactId>spigot</artifactId>
-            <version>1.13.2-R0.1-SNAPSHOT</version>
+            <version>1.7.10-R0.1-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
+        <!-- Netty (implemented in version above 1.7.10) -->
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-all</artifactId>
+            <version>4.1.33.Final</version>
+            <scope>provided</scope>
+        </dependency>
+
     </dependencies>
 </project>

commons/src/main/java/com/comphenix/tinyprotocol/LegacyTinyProtocol.java

@@ -0,0 +1,515 @@
+package com.comphenix.tinyprotocol;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.MapMaker;
+import net.minecraft.util.com.mojang.authlib.GameProfile;
+import net.minecraft.util.io.netty.channel.*;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.event.server.PluginDisableEvent;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import java.util.*;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Level;
+
+/**
+ * Represents a very tiny alternative to ProtocolLib.
+ * <p>
+ * It now supports intercepting packets during login and status ping (such as OUT_SERVER_PING)!
+ *
+ * @author Kristian
+ */
+public abstract class LegacyTinyProtocol {
+    private static final AtomicInteger ID = new AtomicInteger(0);
+
+    // Used in order to lookup a channel
+    private static final Reflection.MethodInvoker getPlayerHandle = Reflection.getMethod("{obc}.entity.CraftPlayer", "getHandle");
+    private static final Reflection.FieldAccessor<Object> getConnection = Reflection.getField("{nms}.EntityPlayer", "playerConnection", Object.class);
+    private static final Reflection.FieldAccessor<Object> getManager = Reflection.getField("{nms}.PlayerConnection", "networkManager", Object.class);
+    private static final Reflection.FieldAccessor<Channel> getChannel = Reflection.getField("{nms}.NetworkManager", Channel.class, 0);
+
+    // Looking up ServerConnection
+    private static final Class<Object> minecraftServerClass = Reflection.getUntypedClass("{nms}.MinecraftServer");
+    private static final Class<Object> serverConnectionClass = Reflection.getUntypedClass("{nms}.ServerConnection");
+    private static final Reflection.FieldAccessor<Object> getMinecraftServer = Reflection.getField("{obc}.CraftServer", minecraftServerClass, 0);
+    private static final Reflection.FieldAccessor<Object> getServerConnection = Reflection.getField(minecraftServerClass, serverConnectionClass, 0);
+    private static final Reflection.MethodInvoker getNetworkMarkers = Reflection.getTypedMethod(serverConnectionClass, null, List.class, serverConnectionClass);
+
+    // Packets we have to intercept
+    private static final Class<?> PACKET_SET_PROTOCOL = Reflection.getMinecraftClass("PacketHandshakingInSetProtocol");
+    private static final Class<?> PACKET_LOGIN_IN_START = Reflection.getMinecraftClass("PacketLoginInStart");
+    private static final Reflection.FieldAccessor<GameProfile> getGameProfile = Reflection.getField(PACKET_LOGIN_IN_START, GameProfile.class, 0);
+    private static final Reflection.FieldAccessor<Integer> protocolId = Reflection.getField(PACKET_SET_PROTOCOL, int.class, 0);
+    private static final Reflection.FieldAccessor<Enum> protocolType = Reflection.getField(PACKET_SET_PROTOCOL, Enum.class, 0);
+
+
+    // Speedup channel lookup
+    private Map<String, Channel> channelLookup = new MapMaker().weakValues().makeMap();
+    private Map<Channel, Integer> protocolLookup = new MapMaker().weakKeys().makeMap();
+    private Listener listener;
+
+    // Channels that have already been removed
+    private Set<Channel> uninjectedChannels = Collections.newSetFromMap(new MapMaker().weakKeys().<Channel, Boolean>makeMap());
+
+    // List of network markers
+    private List<Object> networkManagers;
+
+    // Injected channel handlers
+    private List<Channel> serverChannels = Lists.newArrayList();
+    private ChannelInboundHandlerAdapter serverChannelHandler;
+    private ChannelInitializer<Channel> beginInitProtocol;
+    private ChannelInitializer<Channel> endInitProtocol;
+
+    // Current handler name
+    private String handlerName;
+
+    protected volatile boolean closed;
+    protected Plugin plugin;
+
+    /**
+     * Construct a new instance of TinyProtocol, and start intercepting packets for all connected clients and future clients.
+     * <p>
+     * You can construct multiple instances per plugin.
+     *
+     * @param plugin - the plugin.
+     */
+    public LegacyTinyProtocol(final Plugin plugin) {
+        this.plugin = plugin;
+
+        // Compute handler name
+        this.handlerName = getHandlerName();
+
+        // Prepare existing players
+        registerBukkitEvents();
+
+        try {
+            System.out.println("Attempting to inject into netty");
+            registerChannelHandler();
+            registerPlayers(plugin);
+        } catch (IllegalArgumentException ex) {
+            // Damn you, late bind
+            plugin.getLogger().info("Attempting to delay injection.");
+
+            new BukkitRunnable() {
+                @Override
+                public void run() {
+                    registerChannelHandler();
+                    registerPlayers(plugin);
+                    plugin.getLogger().info("Injection complete.");
+                }
+            }.runTask(plugin);
+        }
+    }
+
+    private void createServerChannelHandler() {
+        // Handle connected channels
+        endInitProtocol = new ChannelInitializer<Channel>() {
+
+            @Override
+            protected void initChannel(Channel channel) throws Exception {
+                try {
+                    // This can take a while, so we need to stop the main thread from interfering
+                    synchronized (networkManagers) {
+                        // Stop injecting channels
+                        if (!closed) {
+                            channel.eventLoop().submit(() -> injectChannelInternal(channel));
+                        }
+                    }
+                } catch (Exception e) {
+                    plugin.getLogger().log(Level.SEVERE, "Cannot inject incomming channel " + channel, e);
+                }
+            }
+
+        };
+
+        // This is executed before Minecraft's channel handler
+        beginInitProtocol = new ChannelInitializer<Channel>() {
+
+            @Override
+            protected void initChannel(Channel channel) throws Exception {
+                channel.pipeline().addLast(endInitProtocol);
+            }
+
+        };
+
+        serverChannelHandler = new ChannelInboundHandlerAdapter() {
+
+            @Override
+            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+                Channel channel = (Channel) msg;
+
+                channel.pipeline().addFirst(beginInitProtocol);
+                ctx.fireChannelRead(msg);
+            }
+
+        };
+    }
+
+    /**
+     * Register bukkit events.
+     */
+    private void registerBukkitEvents() {
+        listener = new Listener() {
+
+            @EventHandler(priority = EventPriority.LOWEST)
+            public final void onPlayerLogin(PlayerJoinEvent e) {
+                if (closed)
+                    return;
+
+                Channel channel = getChannel(e.getPlayer());
+
+                // Don't inject players that have been explicitly uninjected
+                if (!uninjectedChannels.contains(channel)) {
+                    injectPlayer(e.getPlayer());
+                }
+            }
+
+            @EventHandler
+            public final void onPluginDisable(PluginDisableEvent e) {
+                if (e.getPlugin().equals(plugin)) {
+                    close();
+                }
+            }
+
+        };
+
+        plugin.getServer().getPluginManager().registerEvents(listener, plugin);
+    }
+
+    @SuppressWarnings("unchecked")
+    private void registerChannelHandler() {
+        Object mcServer = getMinecraftServer.get(Bukkit.getServer());
+        Object serverConnection = getServerConnection.get(mcServer);
+        boolean looking = true;
+
+        // We need to synchronize against this list
+        networkManagers = (List<Object>) getNetworkMarkers.invoke(null, serverConnection);
+        createServerChannelHandler();
+
+        // Find the correct list, or implicitly throw an exception
+        for (int i = 0; looking; i++) {
+            List<Object> list = Reflection.getField(serverConnection.getClass(), List.class, i).get(serverConnection);
+
+            for (Object item : list) {
+                //if (!ChannelFuture.class.isInstance(item))
+                //	break;
+
+                // Channel future that contains the server connection
+                Channel serverChannel = ((ChannelFuture) item).channel();
+
+                serverChannels.add(serverChannel);
+                ;
+                serverChannel.pipeline().addFirst(serverChannelHandler);
+                System.out.println("Server channel handler injected (" + serverChannel + ")");
+                looking = false;
+            }
+        }
+    }
+
+    private void unregisterChannelHandler() {
+        if (serverChannelHandler == null)
+            return;
+
+        for (Channel serverChannel : serverChannels) {
+            final ChannelPipeline pipeline = serverChannel.pipeline();
+
+            // Remove channel handler
+            serverChannel.eventLoop().execute(() -> {
+                try {
+                    pipeline.remove(serverChannelHandler);
+                } catch (NoSuchElementException e) {
+                    // That's fine
+                }
+            });
+        }
+    }
+
+    private void registerPlayers(Plugin plugin) {
+        for (Player player : plugin.getServer().getOnlinePlayers()) {
+            injectPlayer(player);
+        }
+    }
+
+    /**
+     * Invoked when the server is starting to send a packet to a player.
+     * <p>
+     * Note that this is not executed on the main thread.
+     *
+     * @param receiver - the receiving player, NULL for early login/status packets.
+     * @param packet   - the packet being sent.
+     * @return The packet to send instead, or NULL to cancel the transmission.
+     */
+    public Object onPacketOutAsync(Player receiver, Object packet) {
+        return packet;
+    }
+
+    /**
+     * Invoked when the server has received a packet from a given player.
+     * <p>
+     * Use {@link Channel#remoteAddress()} to get the remote address of the client.
+     *
+     * @param sender - the player that sent the packet, NULL for early login/status packets.
+     * @param packet - the packet being received.
+     * @return The packet to recieve instead, or NULL to cancel.
+     */
+    public Object onPacketInAsync(Player sender, Object packet) {
+        return packet;
+    }
+
+    /**
+     * Send a packet to a particular player.
+     * <p>
+     * Note that {@link #onPacketOutAsync(Player, Object)} will be invoked with this packet.
+     *
+     * @param player - the destination player.
+     * @param packet - the packet to send.
+     */
+    public void sendPacket(Player player, Object packet) {
+        sendPacket(getChannel(player), packet);
+    }
+
+    /**
+     * Send a packet to a particular client.
+     * <p>
+     * Note that {@link #onPacketOutAsync(Player, Object)} will be invoked with this packet.
+     *
+     * @param channel - client identified by a channel.
+     * @param packet  - the packet to send.
+     */
+    public void sendPacket(Channel channel, Object packet) {
+        channel.pipeline().writeAndFlush(packet);
+    }
+
+    /**
+     * Pretend that a given packet has been received from a player.
+     * <p>
+     * Note that {@link #onPacketInAsync(Player, Object)} will be invoked with this packet.
+     *
+     * @param player - the player that sent the packet.
+     * @param packet - the packet that will be received by the server.
+     */
+    public void receivePacket(Player player, Object packet) {
+        receivePacket(getChannel(player), packet);
+    }
+
+    /**
+     * Pretend that a given packet has been received from a given client.
+     * <p>
+     * Note that {@link #onPacketInAsync(Player, Object)} will be invoked with this packet.
+     *
+     * @param channel - client identified by a channel.
+     * @param packet  - the packet that will be received by the server.
+     */
+    public void receivePacket(Channel channel, Object packet) {
+        channel.pipeline().context("encoder").fireChannelRead(packet);
+    }
+
+    /**
+     * Retrieve the name of the channel injector, default implementation is "tiny-" + plugin name + "-" + a unique ID.
+     * <p>
+     * Note that this method will only be invoked once. It is no longer necessary to override this to support multiple instances.
+     *
+     * @return A unique channel handler name.
+     */
+    protected String getHandlerName() {
+        return "tiny-" + plugin.getName() + "-" + ID.incrementAndGet();
+    }
+
+    /**
+     * Add a custom channel handler to the given player's channel pipeline, allowing us to intercept sent and received packets.
+     * <p>
+     * This will automatically be called when a player has logged in.
+     *
+     * @param player - the player to inject.
+     */
+    public void injectPlayer(Player player) {
+        injectChannelInternal(getChannel(player)).player = player;
+    }
+
+    /**
+     * Add a custom channel handler to the given channel.
+     *
+     * @param channel - the channel to inject.
+     * @return The intercepted channel, or NULL if it has already been injected.
+     */
+    public void injectChannel(Channel channel) {
+        injectChannelInternal(channel);
+    }
+
+    /**
+     * Add a custom channel handler to the given channel.
+     *
+     * @param channel - the channel to inject.
+     * @return The packet interceptor.
+     */
+    private PacketInterceptor injectChannelInternal(Channel channel) {
+        try {
+            PacketInterceptor interceptor = (PacketInterceptor) channel.pipeline().get(handlerName);
+
+            // Inject our packet interceptor
+            if (interceptor == null) {
+                interceptor = new PacketInterceptor();
+                channel.pipeline().addBefore("packet_handler", handlerName, interceptor);
+                uninjectedChannels.remove(channel);
+            }
+
+            return interceptor;
+        } catch (IllegalArgumentException e) {
+            // Try again
+            return (PacketInterceptor) channel.pipeline().get(handlerName);
+        }
+    }
+
+    /**
+     * Retrieve the Netty channel associated with a player. This is cached.
+     *
+     * @param player - the player.
+     * @return The Netty channel.
+     */
+    public Channel getChannel(Player player) {
+        Channel channel = channelLookup.get(player.getName());
+
+        // Lookup channel again
+        if (channel == null) {
+            Object connection = getConnection.get(getPlayerHandle.invoke(player));
+            Object manager = getManager.get(connection);
+
+            channelLookup.put(player.getName(), channel = getChannel.get(manager));
+        }
+
+        return channel;
+    }
+
+    public int getProtocolVersion(Player player) {
+        Channel channel = channelLookup.get(player.getName());
+
+        // Lookup channel again
+        if (channel == null) {
+            Object connection = getConnection.get(getPlayerHandle.invoke(player));
+            Object manager = getManager.get(connection);
+
+            channelLookup.put(player.getName(), channel = getChannel.get(manager));
+        }
+
+        return protocolLookup.get(channel);
+    }
+
+    /**
+     * Uninject a specific player.
+     *
+     * @param player - the injected player.
+     */
+    public void uninjectPlayer(Player player) {
+        uninjectChannel(getChannel(player));
+    }
+
+    /**
+     * Uninject a specific channel.
+     * <p>
+     * This will also disable the automatic channel injection that occurs when a player has properly logged in.
+     *
+     * @param channel - the injected channel.
+     */
+    public void uninjectChannel(final Channel channel) {
+        // No need to guard against this if we're closing
+        if (!closed) {
+            uninjectedChannels.add(channel);
+        }
+
+        // See ChannelInjector in ProtocolLib, line 590
+        channel.eventLoop().execute(() -> channel.pipeline().remove(handlerName));
+    }
+
+    /**
+     * Determine if the given player has been injected by TinyProtocol.
+     *
+     * @param player - the player.
+     * @return TRUE if it is, FALSE otherwise.
+     */
+    public boolean hasInjected(Player player) {
+        return hasInjected(getChannel(player));
+    }
+
+    /**
+     * Determine if the given channel has been injected by TinyProtocol.
+     *
+     * @param channel - the channel.
+     * @return TRUE if it is, FALSE otherwise.
+     */
+    public boolean hasInjected(Channel channel) {
+        return channel.pipeline().get(handlerName) != null;
+    }
+
+    /**
+     * Cease listening for packets. This is called automatically when your plugin is disabled.
+     */
+    public final void close() {
+        if (!closed) {
+            closed = true;
+
+            // Remove our handlers
+            for (Player player : plugin.getServer().getOnlinePlayers()) {
+                uninjectPlayer(player);
+            }
+
+            // Clean up Bukkit
+            HandlerList.unregisterAll(listener);
+            unregisterChannelHandler();
+        }
+    }
+
+    /**
+     * Channel handler that is inserted into the player's channel pipeline, allowing us to intercept sent and received packets.
+     *
+     * @author Kristian
+     */
+    private final class PacketInterceptor extends ChannelDuplexHandler {
+        // Updated by the login event
+        public volatile Player player;
+
+        @Override
+        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+            // Intercept channel
+            final Channel channel = ctx.channel();
+            if (PACKET_LOGIN_IN_START.isInstance(msg)) {
+                GameProfile profile = getGameProfile.get(msg);
+                channelLookup.put(profile.getName(), channel);
+            } else if (PACKET_SET_PROTOCOL.isInstance(msg)) {
+                String protocol = protocolType.get(msg).name();
+                if (protocol.equalsIgnoreCase("LOGIN")) {
+                    protocolLookup.put(channel, protocolId.get(msg));
+                }
+            }
+
+            try {
+                msg = onPacketInAsync(player, msg);
+            } catch (Exception e) {
+                plugin.getLogger().log(Level.SEVERE, "Error in onPacketInAsync().", e);
+            }
+
+            if (msg != null) {
+                super.channelRead(ctx, msg);
+            }
+        }
+
+        @Override
+        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
+            try {
+                msg = onPacketOutAsync(player, msg);
+            } catch (Exception e) {
+                plugin.getLogger().log(Level.SEVERE, "Error in onPacketOutAsync().", e);
+            }
+
+            if (msg != null) {
+                super.write(ctx, msg, promise);
+            }
+        }
+    }
+}

commons/src/main/java/com/comphenix/tinyprotocol/TinyProtocol.java

@@ -4,7 +4,6 @@ import com.comphenix.tinyprotocol.Reflection.FieldAccessor;
 import com.comphenix.tinyprotocol.Reflection.MethodInvoker;
 import com.google.common.collect.Lists;
 import com.google.common.collect.MapMaker;
-import com.mojang.authlib.GameProfile;
 import io.netty.channel.*;
 import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
@@ -46,14 +45,15 @@ public abstract class TinyProtocol {
 
     // Packets we have to intercept
     private static final Class<?> PACKET_LOGIN_IN_START = Reflection.getMinecraftClass("PacketLoginInStart");
-    private static final FieldAccessor<GameProfile> getGameProfile = Reflection.getField(PACKET_LOGIN_IN_START, GameProfile.class, 0);
+    private static final FieldAccessor getGameProfile = Reflection.getField(PACKET_LOGIN_IN_START,
+            Reflection.getClass("com.mojang.authlib.GameProfile"), 0);
 
     // Speedup channel lookup
     private Map<String, Channel> channelLookup = new MapMaker().weakValues().makeMap();
     private Listener listener;
 
     // Channels that have already been removed
-    private Set<Channel> uninjectedChannels = Collections.newSetFromMap(new MapMaker().weakKeys().makeMap());
+    private Set<Channel> uninjectedChannels = Collections.newSetFromMap(new MapMaker().weakKeys().<Channel, Boolean>makeMap());
 
     // List of network markers
     private List<Object> networkManagers;
@@ -339,6 +339,7 @@ public abstract class TinyProtocol {
      * Add a custom channel handler to the given channel.
      *
      * @param channel - the channel to inject.
+     * @return The intercepted channel, or NULL if it has already been injected.
      */
     public void injectChannel(Channel channel) {
         injectChannelInternal(channel);
@@ -411,7 +412,14 @@ public abstract class TinyProtocol {
         }
 
         // See ChannelInjector in ProtocolLib, line 590
-        channel.eventLoop().execute(() -> channel.pipeline().remove(handlerName));
+        channel.eventLoop().execute(new Runnable() {
+
+            @Override
+            public void run() {
+                channel.pipeline().remove(handlerName);
+            }
+
+        });
     }
 
     /**
@@ -493,8 +501,8 @@ public abstract class TinyProtocol {
 
         private void handleLoginStart(Channel channel, Object packet) {
             if (PACKET_LOGIN_IN_START.isInstance(packet)) {
-                GameProfile profile = getGameProfile.get(packet);
+                Object profile = getGameProfile.get(packet);
-                channelLookup.put(profile.getName(), channel);
+                channelLookup.put((String) Reflection.getMethod(profile.getClass(), "getName").invoke(profile), channel);
             }
         }
     }

commons/src/main/java/net/jitse/npclib/NPCLib.java

@@ -6,9 +6,11 @@ package net.jitse.npclib;
 
 import net.jitse.npclib.api.NPC;
 import net.jitse.npclib.listeners.ChunkListener;
+import net.jitse.npclib.listeners.LegacyPacketListener;
 import net.jitse.npclib.listeners.PacketListener;
 import net.jitse.npclib.listeners.PlayerListener;
 import net.jitse.npclib.skin.Skin;
+import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.Server;
 import org.bukkit.plugin.PluginManager;
@@ -64,8 +66,13 @@ public class NPCLib {
         pluginManager.registerEvents(new PlayerListener(), plugin);
         pluginManager.registerEvents(new ChunkListener(), plugin);
 
+        // Boot the according packet listener.
+        if (Bukkit.getBukkitVersion().contains("1.7")) {
+            new LegacyPacketListener().start(plugin);
+        } else {
             new PacketListener().start(plugin);
         }
+    }
 
     /**
      * Create a new non-player character (NPC).

commons/src/main/java/net/jitse/npclib/api/NPC.java

@@ -4,9 +4,8 @@
 
 package net.jitse.npclib.api;
 
-import com.mojang.authlib.GameProfile;
-import com.mojang.authlib.properties.Property;
 import net.jitse.npclib.NPCManager;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.jitse.npclib.events.NPCDestroyEvent;
 import net.jitse.npclib.events.NPCSpawnEvent;
 import net.jitse.npclib.events.trigger.TriggerType;
@@ -39,7 +38,7 @@ public abstract class NPC implements PacketHandler, ActionHandler {
     protected final List<String> lines;
 
     protected JavaPlugin plugin;
-    protected GameProfile gameProfile;
+    protected GameProfileWrapper gameProfile;
     protected Location location;
 
     public NPC(JavaPlugin plugin, Skin skin, double autoHideDistance, List<String> lines) {
@@ -51,11 +50,11 @@ public abstract class NPC implements PacketHandler, ActionHandler {
         NPCManager.add(this);
     }
 
-    protected GameProfile generateGameProfile(UUID uuid, String name) {
+    protected GameProfileWrapper generateGameProfile(UUID uuid, String name) {
-        GameProfile gameProfile = new GameProfile(uuid, name);
+        GameProfileWrapper gameProfile = new GameProfileWrapper(uuid, name);
 
         if (skin != null) {
-            gameProfile.getProperties().put("textures", new Property("textures", skin.getValue(), skin.getSignature()));
+            gameProfile.addSkin(skin);
         }
 
         return gameProfile;

commons/src/main/java/net/jitse/npclib/api/wrapper/GameProfileWrapper.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018 Jitse Boonstra
+ */
+
+package net.jitse.npclib.api.wrapper;
+
+import com.comphenix.tinyprotocol.Reflection;
+import com.google.common.collect.ForwardingMultimap;
+import net.jitse.npclib.skin.Skin;
+import org.bukkit.Bukkit;
+
+import java.util.UUID;
+
+public class GameProfileWrapper {
+
+    // Written because of issue#10 (https://github.com/JitseB/NPCLib/issues/10).
+    // This class acts as an NMS reflection wrapper for the GameProfileWrapper class.
+
+    // TODO: Add this class to the v1_7_R4 module of NPCLib.
+
+    private final boolean is1_7 = Bukkit.getBukkitVersion().contains("1.7");
+    private final Class<?> gameProfileClazz = Reflection.getClass((is1_7 ? "net.minecraft.util." : "") + "com.mojang.authlib.GameProfile");
+
+    Object gameProfile;
+
+    public GameProfileWrapper(UUID uuid, String name) {
+        // Only need to check if the version is 1.7, as NPCLib doesn't support any version below this version.
+        this.gameProfile = Reflection.getConstructor(gameProfileClazz, UUID.class, String.class).invoke(uuid, name);
+    }
+
+    public void addSkin(Skin skin) {
+        // Create a new property with the skin data.
+        Class<?> propertyClazz = Reflection.getClass((is1_7 ? "net.minecraft.util." : "") + "com.mojang.authlib.properties.Property");
+        Object property = Reflection.getConstructor(propertyClazz,
+                String.class, String.class, String.class).invoke("textures", skin.getValue(), skin.getSignature());
+
+        // Get the property map from the GameProfileWrapper object.
+        Class<?> propertyMapClazz = Reflection.getClass((is1_7 ? "net.minecraft.util." : "") + "com.mojang.authlib.properties.PropertyMap");
+        Reflection.FieldAccessor propertyMapGetter = Reflection.getField(gameProfileClazz, "properties",
+                propertyMapClazz);
+        Object propertyMap = propertyMapGetter.get(gameProfile);
+
+        // Add our new property to the property map.
+        Reflection.getMethod(ForwardingMultimap.class, "put", Object.class, Object.class)
+                .invoke(propertyMap, "textures", property);
+
+        // Finally set the property map back in the GameProfileWrapper object.
+        propertyMapGetter.set(gameProfile, propertyMap);
+    }
+
+    public Object getGameProfile() {
+        return gameProfile;
+    }
+}

commons/src/main/java/net/jitse/npclib/listeners/LegacyPacketListener.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2018 Jitse Boonstra
+ */
+
+package net.jitse.npclib.listeners;
+
+import com.comphenix.tinyprotocol.LegacyTinyProtocol;
+import com.comphenix.tinyprotocol.Reflection;
+import net.jitse.npclib.NPCManager;
+import net.jitse.npclib.api.NPC;
+import net.jitse.npclib.events.NPCInteractEvent;
+import net.jitse.npclib.events.click.ClickType;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.java.JavaPlugin;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+/**
+ * @author Jitse Boonstra
+ */
+public class LegacyPacketListener {
+
+    // Classes:
+    private final Class<?> packetPlayInUseEntityClazz = Reflection.getMinecraftClass("PacketPlayInUseEntity");
+
+    // Fields:
+    private final Reflection.FieldAccessor entityIdField = Reflection.getField(packetPlayInUseEntityClazz, "a", int.class);
+    private final Reflection.FieldAccessor actionField = Reflection.getField(packetPlayInUseEntityClazz, "action", Object.class);
+
+    // Prevent players from clicking at very high speeds.
+    private final Set<UUID> delay = new HashSet<>();
+
+    public void start(JavaPlugin plugin) {
+        new LegacyTinyProtocol(plugin) {
+
+            @Override
+            public Object onPacketInAsync(Player player, Object packet) {
+
+                if (packetPlayInUseEntityClazz.isInstance(packet)) {
+                    NPC npc = NPCManager.getAllNPCs().stream().filter(
+                            check -> check.isActuallyShown(player) && check.getEntityId() == (int) entityIdField.get(packet))
+                            .findFirst().orElse(null);
+
+                    if (npc == null) {
+                        // Default player, not doing magic with the packet.
+                        return super.onPacketInAsync(player, packet);
+                    }
+
+                    if (delay.contains(player.getUniqueId())) {
+                        return null;
+                    }
+
+                    ClickType clickType = actionField.get(packet).toString()
+                            .equals("ATTACK") ? ClickType.LEFT_CLICK : ClickType.RIGHT_CLICK;
+
+                    Bukkit.getPluginManager().callEvent(new NPCInteractEvent(player, clickType, npc));
+
+                    UUID uuid = player.getUniqueId();
+                    delay.add(uuid);
+                    Bukkit.getScheduler().runTask(plugin, () -> delay.remove(uuid));
+                    return null;
+                }
+
+                return super.onPacketInAsync(player, packet);
+            }
+        };
+    }
+}

commons/src/main/java/net/jitse/npclib/listeners/PacketListener.java

@@ -5,6 +5,14 @@
 package net.jitse.npclib.listeners;
 
 import com.comphenix.tinyprotocol.Reflection;
+import com.comphenix.tinyprotocol.TinyProtocol;
+import io.netty.channel.Channel;
+import net.jitse.npclib.NPCManager;
+import net.jitse.npclib.api.NPC;
+import net.jitse.npclib.events.NPCInteractEvent;
+import net.jitse.npclib.events.click.ClickType;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.util.HashSet;
@@ -27,38 +35,38 @@ public class PacketListener {
     private final Set<UUID> delay = new HashSet<>();
 
     public void start(JavaPlugin plugin) {
-//        new TinyProtocol(plugin) {
+        new TinyProtocol(plugin) {
-//
+
-//            @Override
+            @Override
-//            public Object onPacketInAsync(Player player, Channel channel, Object packet) {
+            public Object onPacketInAsync(Player player, Channel channel, Object packet) {
-//
+
-//                if (packetPlayInUseEntityClazz.isInstance(packet)) {
+                if (packetPlayInUseEntityClazz.isInstance(packet)) {
-//                    NPC npc = NPCManager.getAllNPCs().stream().filter(
+                    NPC npc = NPCManager.getAllNPCs().stream().filter(
-//                            check -> check.isActuallyShown(player) && check.getEntityId() == (int) entityIdField.get(packet))
+                            check -> check.isActuallyShown(player) && check.getEntityId() == (int) entityIdField.get(packet))
-//                            .findFirst().orElse(null);
+                            .findFirst().orElse(null);
-//
+
-//                    if (npc == null) {
+                    if (npc == null) {
-//                        // Default player, not doing magic with the packet.
+                        // Default player, not doing magic with the packet.
-//                        return super.onPacketInAsync(player, channel, packet);
+                        return super.onPacketInAsync(player, channel, packet);
-//                    }
+                    }
-//
+
-//                    if (delay.contains(player.getUniqueId())) {
+                    if (delay.contains(player.getUniqueId())) {
-//                        return null;
+                        return null;
-//                    }
+                    }
-//
+
-//                    ClickType clickType = actionField.get(packet).toString()
+                    ClickType clickType = actionField.get(packet).toString()
-//                            .equals("ATTACK") ? ClickType.LEFT_CLICK : ClickType.RIGHT_CLICK;
+                            .equals("ATTACK") ? ClickType.LEFT_CLICK : ClickType.RIGHT_CLICK;
-//
+
-//                    Bukkit.getPluginManager().callEvent(new NPCInteractEvent(player, clickType, npc));
+                    Bukkit.getPluginManager().callEvent(new NPCInteractEvent(player, clickType, npc));
-//
+
-//                    UUID uuid = player.getUniqueId();
+                    UUID uuid = player.getUniqueId();
-//                    delay.add(uuid);
+                    delay.add(uuid);
-//                    Bukkit.getScheduler().runTask(plugin, () -> delay.remove(uuid));
+                    Bukkit.getScheduler().runTask(plugin, () -> delay.remove(uuid));
-//                    return null;
+                    return null;
-//                }
+                }
-//
+
-//                return super.onPacketInAsync(player, channel, packet);
+                return super.onPacketInAsync(player, channel, packet);
-//            }
+            }
-//        };
+        };
     }
 }

nms/v1_10_R1/src/main/java/net/jitse/npclib/nms/v1_10_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_10_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_10_R1.EnumGamemode;
 import net.minecraft.server.v1_10_R1.IChatBaseComponent;
 import net.minecraft.server.v1_10_R1.PacketPlayOutPlayerInfo;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_11_R1/src/main/java/net/jitse/npclib/nms/v1_11_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_11_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_11_R1.EnumGamemode;
 import net.minecraft.server.v1_11_R1.IChatBaseComponent;
 import net.minecraft.server.v1_11_R1.PacketPlayOutPlayerInfo;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_12_R1/src/main/java/net/jitse/npclib/nms/v1_12_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_12_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_12_R1.EnumGamemode;
 import net.minecraft.server.v1_12_R1.IChatBaseComponent;
 import net.minecraft.server.v1_12_R1.PacketPlayOutPlayerInfo;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_13_R1/src/main/java/net/jitse/npclib/nms/v1_13_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_13_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_13_R1.EnumGamemode;
 import net.minecraft.server.v1_13_R1.IChatBaseComponent;
 import net.minecraft.server.v1_13_R1.PacketPlayOutPlayerInfo;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_13_R2/src/main/java/net/jitse/npclib/nms/v1_13_R2/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_13_R2.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_13_R2.EnumGamemode;
 import net.minecraft.server.v1_13_R2.IChatBaseComponent;
 import net.minecraft.server.v1_13_R2.PacketPlayOutPlayerInfo;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_8_R1/src/main/java/net/jitse/npclib/nms/v1_8_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_8_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_8_R1.*;
 
 import java.util.List;
@@ -15,7 +16,9 @@ import java.util.List;
  */
 public class PacketPlayOutPlayerInfoWrapper {
 
-    public PacketPlayOutPlayerInfo create(EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_8_R2/src/main/java/net/jitse/npclib/nms/v1_8_R2/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_8_R2.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_8_R2.IChatBaseComponent;
 import net.minecraft.server.v1_8_R2.PacketPlayOutPlayerInfo;
 import net.minecraft.server.v1_8_R2.WorldSettings;
@@ -17,7 +18,9 @@ import java.util.List;
  */
 public class PacketPlayOutPlayerInfoWrapper {
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_8_R3/src/main/java/net/jitse/npclib/nms/v1_8_R3/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_8_R3.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_8_R3.IChatBaseComponent;
 import net.minecraft.server.v1_8_R3.PacketPlayOutPlayerInfo;
 import net.minecraft.server.v1_8_R3.WorldSettings;
@@ -17,7 +18,9 @@ import java.util.List;
  */
 public class PacketPlayOutPlayerInfoWrapper {
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_9_R1/src/main/java/net/jitse/npclib/nms/v1_9_R1/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_9_R1.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_9_R1.IChatBaseComponent;
 import net.minecraft.server.v1_9_R1.PacketPlayOutPlayerInfo;
 import net.minecraft.server.v1_9_R1.WorldSettings;
@@ -18,7 +19,9 @@ import java.util.List;
  */
 public class PacketPlayOutPlayerInfoWrapper {
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);

nms/v1_9_R2/src/main/java/net/jitse/npclib/nms/v1_9_R2/packets/PacketPlayOutPlayerInfoWrapper.java

@@ -6,6 +6,7 @@ package net.jitse.npclib.nms.v1_9_R2.packets;
 
 import com.comphenix.tinyprotocol.Reflection;
 import com.mojang.authlib.GameProfile;
+import net.jitse.npclib.api.wrapper.GameProfileWrapper;
 import net.minecraft.server.v1_9_R2.IChatBaseComponent;
 import net.minecraft.server.v1_9_R2.PacketPlayOutPlayerInfo;
 import net.minecraft.server.v1_9_R2.WorldSettings;
@@ -23,7 +24,9 @@ public class PacketPlayOutPlayerInfoWrapper {
     private final Reflection.ConstructorInvoker playerInfoDataConstructor = Reflection.getConstructor(playerInfoDataClazz,
             packetPlayOutPlayerInfoClazz, GameProfile.class, int.class, WorldSettings.EnumGamemode.class, IChatBaseComponent.class);
 
-    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfile gameProfile, String name) {
+    public PacketPlayOutPlayerInfo create(PacketPlayOutPlayerInfo.EnumPlayerInfoAction action, GameProfileWrapper gameProfileWrapper, String name) {
+        GameProfile gameProfile = (GameProfile) gameProfileWrapper.getGameProfile();
+
         PacketPlayOutPlayerInfo packetPlayOutPlayerInfo = new PacketPlayOutPlayerInfo();
         Reflection.getField(packetPlayOutPlayerInfo.getClass(), "a", PacketPlayOutPlayerInfo.EnumPlayerInfoAction.class)
                 .set(packetPlayOutPlayerInfo, action);