Prevent PacketPlayOutPlayerInfo from being sent.

IgnoreTabList.java

package com.comphenix.example;

import java.util.Set;

import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;

import com.comphenix.protocol.PacketType;
import com.comphenix.protocol.ProtocolLibrary;
import com.comphenix.protocol.events.PacketAdapter;
import com.comphenix.protocol.events.PacketEvent;
import com.google.common.collect.Sets;

public class IgnoreTabList extends JavaPlugin {
    private Set<String> ignoreTabList = Sets.newHashSet();
    
    @Override
    public void onEnable() {
        ProtocolLibrary.getProtocolManager().addPacketListener(
          new PacketAdapter(this, PacketType.Play.Server.PLAYER_INFO) {
            @Override
            public void onPacketSending(PacketEvent event) {
                String name = event.getPacket().getStrings().read(0);
                
                if (ignoreTabList.contains(name)) {
                    event.setCancelled(true);
                }
            }
        });
    }
    
    private void ignore(Player player) {
        ignoreTabList.add(player.getPlayerListName());
    }
    
    public void unignore(Player player) {
        ignoreTabList.remove(player.getPlayerListName());
    }
    
    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if (args.length != 1) {
            sender.sendMessage(ChatColor.RED + "Must have one argument.");
        } else if (sender instanceof Player) {
            Player observer = (Player) sender;
            Player player = getServer().getPlayer(args[0]);
            
            // Stop sending tab list packets about this player
            ignore(player);
            
            if (observer.canSee(player)) {
                observer.hidePlayer(player);
            } else {
                observer.showPlayer(player);
            }
            
            unignore(player);
        }
        return true;
    }
}