Added async PreLoginEvent to change online mode per connection.

api/src/main/java/net/md_5/bungee/api/connection/PendingConnection.java

@@ -43,4 +43,18 @@ public interface PendingConnection extends Connection
      * @return the UUID
      */
     String getUUID();
+    
+    /**
+     * Get this connection's online mode.
+     *
+     * @return the online mode
+     */
+    boolean isOnlineMode();
+    
+    /**
+     * Set this connection's online mode.
+     * 
+     * @param onlineMode 
+     */
+    void setOnlineMode(boolean onlineMode);
 }

api/src/main/java/net/md_5/bungee/api/event/PreLoginEvent.java

@@ -0,0 +1,37 @@
+package net.md_5.bungee.api.event;
+
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+import net.md_5.bungee.api.Callback;
+import net.md_5.bungee.api.connection.PendingConnection;
+import net.md_5.bungee.api.plugin.Cancellable;
+
+/**
+ * Event called to represent a player first making their presence and username
+ * known.
+ */
+@Data
+@ToString(callSuper = false)
+@EqualsAndHashCode(callSuper = false)
+public class PreLoginEvent extends AsyncEvent<PreLoginEvent> implements Cancellable {
+
+    /**
+     * Cancelled state.
+     */
+    private boolean cancelled;
+    /**
+     * Message to use when kicking if this event is canceled.
+     */
+    private String cancelReason;
+    /**
+     * Connection attempting to login.
+     */
+    private final PendingConnection connection;
+
+    public PreLoginEvent(PendingConnection connection, Callback<PreLoginEvent> done)
+    {
+        super( done );
+        this.connection = connection;
+    }
+}

proxy/src/main/java/net/md_5/bungee/connection/InitialHandler.java

@@ -13,6 +13,7 @@ import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import lombok.Setter;
 import net.md_5.bungee.BungeeCord;
 import net.md_5.bungee.EncryptionUtil;
 import net.md_5.bungee.UserConnection;
@@ -44,6 +45,7 @@ import net.md_5.bungee.protocol.packet.EncryptionRequest;
 import net.md_5.bungee.protocol.packet.Kick;
 import net.md_5.bungee.api.AbstractReconnectHandler;
 import net.md_5.bungee.api.event.PlayerHandshakeEvent;
+import net.md_5.bungee.api.event.PreLoginEvent;
 import net.md_5.bungee.protocol.Protocol;
 import net.md_5.bungee.protocol.packet.LegacyPing;
 import net.md_5.bungee.protocol.packet.LoginRequest;
@@ -251,7 +253,21 @@ public class InitialHandler extends PacketHandler implements PendingConnection
         // TODO: Nuuuu Mojang why u do this
         // unsafe().sendPacket( PacketConstants.I_AM_BUNGEE );
         // unsafe().sendPacket( PacketConstants.FORGE_MOD_REQUEST );
-        if ( this.onlineMode )
+        Callback<PreLoginEvent> callback = new Callback<PreLoginEvent>()
+        {
+
+            @Override
+            public void done(PreLoginEvent result, Throwable error)
+            {
+                if ( result.isCancelled() )
+                {
+                    disconnect( result.getCancelReason() );
+                }
+                if ( ch.isClosed() )
+                {
+                    return;
+                }
+                if ( InitialHandler.this.onlineMode )
                 {
                     unsafe().sendPacket( request = EncryptionUtil.encryptRequest() );
                 } else
@@ -260,6 +276,11 @@ public class InitialHandler extends PacketHandler implements PendingConnection
                 }
                 thisState = State.ENCRYPT;
             }
+        };
+        
+        // fire pre login event
+        bungee.getPluginManager().callEvent( new PreLoginEvent( InitialHandler.this, callback ) );
+    }
 
     @Override
     public void handle(final EncryptionResponse encryptResponse) throws Exception
@@ -417,9 +438,10 @@ public class InitialHandler extends PacketHandler implements PendingConnection
         return unsafe;
     }
 
+    @Override
     public void setOnlineMode(boolean onlineMode)
     {
-        Preconditions.checkState( thisState == State.HANDSHAKE, "Can only set online mode status whilst handshaking" );
+        Preconditions.checkState( thisState == State.USERNAME, "Can only set online mode status whilst state is username" );
         this.onlineMode = onlineMode;
     }