Made the "getPlugin" method mandatory for all listeners.

It's pretty useful for the data collector, as well as the utility
method "removePacketListeners".

ProtocolLib/src/com/comphenix/protocol/ProtocolLibrary.java

@@ -9,8 +9,6 @@ import org.bukkit.plugin.PluginManager;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import com.comphenix.protocol.injector.PacketFilterManager;
-import com.comphenix.protocol.metrics.Metrics;
-import com.comphenix.protocol.metrics.Metrics.Plotter;
 import com.comphenix.protocol.metrics.Statistics;
 
 public class ProtocolLibrary extends JavaPlugin {

ProtocolLib/src/com/comphenix/protocol/ProtocolManager.java

@@ -40,7 +40,7 @@ public interface ProtocolManager {
 	 * Note that this only works for listeners that derive from PacketAdapter.
 	 * @param plugin - the plugin to unload.
 	 */
-	public void removePacketAdapters(Plugin plugin);
+	public void removePacketListeners(Plugin plugin);
 	
 	/**
 	 * Send a packet to the given player.

ProtocolLib/src/com/comphenix/protocol/events/PacketAdapter.java

@@ -50,10 +50,7 @@ public abstract class PacketAdapter implements PacketListener {
 		return packetsID;
 	}
 	
-	/**
-	 * Retrieves the plugin associated with this listener.
-	 * @return The associated plugin.
-	 */
+	@Override
 	public Plugin getPlugin() {
 		return plugin;
 	}
@@ -62,10 +59,17 @@ public abstract class PacketAdapter implements PacketListener {
 	 * Retrieves the name of the plugin that has been associated with the listener.
 	 * @return Name of the associated plugin.
 	 */
-	public String getPluginName() {
+	public static String getPluginName(PacketListener listener) {
+		
+		Plugin plugin = listener.getPlugin();
+		
 		// Try to get the plugin name
 		try {
-			return plugin.getName();
+			if (plugin == null)
+				return "UNKNOWN";
+			else
+				return plugin.getName();
+			
 		} catch (NoSuchMethodError e) {
 			return plugin.toString();
 		}
@@ -75,7 +79,7 @@ public abstract class PacketAdapter implements PacketListener {
 	public String toString() {		
 		// This is used by the error reporter 
 		return String.format("PacketAdapter[plugin=%s, side=%s, packets=%s]", 
-				getPluginName(), getConnectionSide().name(), 
+				getPluginName(this), getConnectionSide().name(), 
 				Joiner.on(", ").join(packetsID));
 	}
 }

ProtocolLib/src/com/comphenix/protocol/events/PacketListener.java

@@ -2,6 +2,8 @@ package com.comphenix.protocol.events;
 
 import java.util.Set;
 
+import org.bukkit.plugin.Plugin;
+
 
 public interface PacketListener {
 	
@@ -31,4 +33,10 @@ public interface PacketListener {
 	 * @return Packets IDs.
 	 */
 	public Set<Integer> getPacketsID();
+	
+	/**
+	 * Retrieve the plugin that created list packet listener.
+	 * @return The plugin, or NULL if not available.
+	 */
+	public Plugin getPlugin();
 }

ProtocolLib/src/com/comphenix/protocol/injector/PacketFilterManager.java

@@ -27,11 +27,11 @@ import org.bukkit.plugin.PluginManager;
 
 import com.comphenix.protocol.ProtocolManager;
 import com.comphenix.protocol.events.ConnectionSide;
-import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.events.PacketContainer;
 import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.events.PacketListener;
 import com.comphenix.protocol.reflect.FuzzyReflection;
+import com.google.common.base.Objects;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
 
@@ -107,17 +107,15 @@ public final class PacketFilterManager implements ProtocolManager {
 	}
 	
 	@Override
-	public void removePacketAdapters(Plugin plugin) {
+	public void removePacketListeners(Plugin plugin) {
 		
 		// Iterate through every packet listener
-		for (Object listener : packetListeners.toArray()) {
-			if (listener instanceof PacketAdapter) {
-				PacketAdapter adapter = (PacketAdapter) listener;
-				
-				// Remove the listener
-				if (adapter.getPlugin().equals(plugin)) {
-					packetListeners.remove(listener);
-				}
+		for (Object element : packetListeners.toArray()) {			
+			PacketListener listener = (PacketListener) element;
+
+			// Remove the listener
+			if (Objects.equal(listener.getPlugin(), plugin)) {
+				packetListeners.remove(listener);
 			}
 		}
 	}

ProtocolLib/src/com/comphenix/protocol/metrics/Statistics.java

@@ -49,13 +49,7 @@ public class Statistics {
 			
 		for (PacketListener listener : manager.getPacketListeners()) {
 			
-			String name = "UNKNOWN";
-			
-			if (listener instanceof PacketAdapter) {
-				PacketAdapter adapter = (PacketAdapter) listener;
-				name = adapter.getPluginName();
-			}
-			
+			String name = PacketAdapter.getPluginName(listener);
 			
 			// Increment occurence
 			if (!users.containsKey(name)) {