Add PacketSentEvent

src/main/java/net/minecraft/server/NetServerHandler.java

···
 import org.bukkit.event.block.BlockRedstoneEvent;
 import org.bukkit.event.block.SignChangeEvent;
 import org.bukkit.event.packet.PacketReceivedEvent;
+import org.bukkit.event.packet.PacketSentEvent;
 import org.bukkit.event.player.PlayerAnimationEvent;
 import org.bukkit.event.player.PlayerChatEvent;
 import org.bukkit.event.player.PlayerCommandPreprocessEvent;
···
         }
         //Poseidon End
 
+        // UberBukkit
+        PacketSentEvent packetSentEvent = new PacketSentEvent(getPlayer(), packet);
+        Bukkit.getPluginManager().callEvent(packetSentEvent);
+        if (packetSentEvent.isCancelled()) {
+            return;
+        }
+        packet = packetSentEvent.getPacket();
 
-        // uberbukkit
         Protocol protocol = Uberbukkit.getProtocolHandler();
         if (!protocol.canReceivePacket(packet.b())) {
             this.g = this.f;

src/main/java/org/bukkit/event/Event.java

···
 
         PACKET_RECEIVED(Category.PACKET),
 
+        PACKET_SENT(Category.PACKET),
+
 
         /**
          * Called when a player first starts their connection. Called before UUID is known.

src/main/java/org/bukkit/event/packet/PacketListener.java

···
 /**
  * @author moderator_man
  */
-public class PacketListener implements Listener
-{
+public class PacketListener implements Listener {
     public void onPacketReceived(PacketReceivedEvent event) {}
+    public void onPacketSent(PacketSentEvent event) {}
 }

src/main/java/org/bukkit/event/packet/PacketSentEvent.java

···
+package org.bukkit.event.packet;
+
+import net.minecraft.server.Packet;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+public class PacketSentEvent extends Event {
+    private Player player;
+    private Packet packet;
+    private boolean cancelled;
+
+    public PacketSentEvent(Player player, Packet packet) {
+        super(Type.PACKET_SENT);
+
+        this.player = player;
+        this.packet = packet;
+    }
+
+    @Nullable
+    public Player getPlayer() {
+        return player;
+    }
+
+    public Packet getPacket() {
+        return packet;
+    }
+
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    public void setCancelled(boolean cancelled) {
+        this.cancelled = cancelled;
+    }
+}

src/main/java/org/bukkit/plugin/java/JavaPluginLoader.java

···
 import org.bukkit.event.inventory.InventoryTransactionEvent;
 import org.bukkit.event.packet.PacketListener;
 import org.bukkit.event.packet.PacketReceivedEvent;
+import org.bukkit.event.packet.PacketSentEvent;
 import org.bukkit.event.painting.PaintingBreakEvent;
 import org.bukkit.event.painting.PaintingPlaceEvent;
 import org.bukkit.event.player.*;
···
 
         switch (type)
         {
+            // UberBukkit events
+            case PACKET_SENT:
+                return new EventExecutor() {
+                    public void execute(Listener listener, Event event) {
+                        ((PacketListener) listener).onPacketSent((PacketSentEvent) event);
+                    }
+                };
+
             // Poseidon events
             case PACKET_RECEIVED:
                 return new EventExecutor()