SpigotMC#2447: Add API for fluent server connect requests

API allows for more control over callback to see why the callback was performed whilst maintaining backwards compatibility

api/src/main/java/net/md_5/bungee/api/ServerConnectRequest.java

@@ -0,0 +1,78 @@
+package net.md_5.bungee.api;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NonNull;
+import net.md_5.bungee.api.config.ServerInfo;
+import net.md_5.bungee.api.event.ServerConnectEvent;
+
+/**
+ * A request to connect a server.
+ */
+@Getter
+@Builder(builderClassName = "Builder")
+public class ServerConnectRequest
+{
+
+    /**
+     * The result from this callback after request has been executed by proxy.
+     */
+    public enum Result
+    {
+
+        /**
+         * ServerConnectEvent to the new server was canceled.
+         */
+        EVENT_CANCEL,
+        /**
+         * Already connected to target server.
+         */
+        ALREADY_CONNECTED,
+        /**
+         * Already connecting to target server.
+         */
+        ALREADY_CONNECTING,
+        /**
+         * Successfully connected to server.
+         */
+        SUCCESS,
+        /**
+         * Connection failed, error can be accessed from callback method handle.
+         */
+        FAIL
+    }
+
+    /**
+     * Target server to connect to.
+     */
+    @NonNull
+    private final ServerInfo target;
+    /**
+     * Reason for connecting to server.
+     */
+    @NonNull
+    private final ServerConnectEvent.Reason reason;
+    /**
+     * Callback to execute post request.
+     */
+    private final Callback<Result> callback;
+    /**
+     * Timeout in milliseconds for request.
+     */
+    private final int connectTimeout;
+    /**
+     * Should the player be attempted to connect to the next server in their
+     * queue if the initial request fails.
+     */
+    private final boolean retry;
+
+    /**
+     * Class that sets default properties/adds methods to the lombok builder
+     * generated class.
+     */
+    public static class ServerConnectRequestBuilder
+    {
+
+        private int connectTimeout = 5000; // TODO: Configurable
+    }
+}

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

@@ -6,6 +6,7 @@
 import net.md_5.bungee.api.Callback;
 import net.md_5.bungee.api.ChatMessageType;
 import net.md_5.bungee.api.CommandSender;
+import net.md_5.bungee.api.ServerConnectRequest;
 import net.md_5.bungee.api.SkinConfiguration;
 import net.md_5.bungee.api.Title;
 import net.md_5.bungee.api.chat.BaseComponent;
@@ -123,6 +124,15 @@ public enum MainHand
      */
     void connect(ServerInfo target, Callback<Boolean> callback, ServerConnectEvent.Reason reason);
 
+    /**
+     * Connects / transfers this user to the specified connection, gracefully
+     * closing the current one. Depending on the implementation, this method
+     * might return before the user has been connected.
+     *
+     * @param request request to connect with
+     */
+    void connect(ServerConnectRequest request);
+
     /**
      * Gets the server this player is connected to.
      *

proxy/src/main/java/net/md_5/bungee/UserConnection.java

@@ -27,6 +27,7 @@
 import net.md_5.bungee.api.Callback;
 import net.md_5.bungee.api.ChatMessageType;
 import net.md_5.bungee.api.ProxyServer;
+import net.md_5.bungee.api.ServerConnectRequest;
 import net.md_5.bungee.api.SkinConfiguration;
 import net.md_5.bungee.api.Title;
 import net.md_5.bungee.api.chat.BaseComponent;
@@ -253,12 +254,35 @@ public void connect(ServerInfo info, final Callback<Boolean> callback, final boo
     {
         Preconditions.checkNotNull( info, "info" );
 
-        ServerConnectEvent event = new ServerConnectEvent( this, info, reason );
+        ServerConnectRequest.Builder builder = ServerConnectRequest.builder().retry( retry ).reason( reason ).target( info );
+        if ( callback != null )
+        {
+            // Convert the Callback<Boolean> to be compatible with Callback<Result> from ServerConnectRequest.
+            builder.callback( new Callback<ServerConnectRequest.Result>()
+            {
+                @Override
+                public void done(ServerConnectRequest.Result result, Throwable error)
+                {
+                    callback.done( ( result == ServerConnectRequest.Result.SUCCESS ) ? Boolean.TRUE : Boolean.FALSE, error );
+                }
+            } );
+        }
+
+        connect( builder.build() );
+    }
+
+    @Override
+    public void connect(final ServerConnectRequest request)
+    {
+        Preconditions.checkNotNull( request, "request" );
+
+        final Callback<ServerConnectRequest.Result> callback = request.getCallback();
+        ServerConnectEvent event = new ServerConnectEvent( this, request.getTarget(), request.getReason() );
         if ( bungee.getPluginManager().callEvent( event ).isCancelled() )
         {
             if ( callback != null )
             {
-                callback.done( false, null );
+                callback.done( ServerConnectRequest.Result.EVENT_CANCEL, null );
             }
 
             if ( getServer() == null && !ch.isClosing() )
@@ -274,7 +298,7 @@ public void connect(ServerInfo info, final Callback<Boolean> callback, final boo
         {
             if ( callback != null )
             {
-                callback.done( false, null );
+                callback.done( ServerConnectRequest.Result.ALREADY_CONNECTED, null );
             }
 
             sendMessage( bungee.getTranslation( "already_connected" ) );
@@ -284,7 +308,7 @@ public void connect(ServerInfo info, final Callback<Boolean> callback, final boo
         {
             if ( callback != null )
             {
-                callback.done( false, null );
+                callback.done( ServerConnectRequest.Result.ALREADY_CONNECTING, null );
             }
 
             sendMessage( bungee.getTranslation( "already_connecting" ) );
@@ -312,7 +336,7 @@ public void operationComplete(ChannelFuture future) throws Exception
             {
                 if ( callback != null )
                 {
-                    callback.done( future.isSuccess(), future.cause() );
+                    callback.done( ( future.isSuccess() ) ? ServerConnectRequest.Result.SUCCESS : ServerConnectRequest.Result.FAIL, future.cause() );
                 }
 
                 if ( !future.isSuccess() )
@@ -321,7 +345,7 @@ public void operationComplete(ChannelFuture future) throws Exception
                     pendingConnects.remove( target );
 
                     ServerInfo def = updateAndGetNextServer( target );
-                    if ( retry && def != null && ( getServer() == null || def != getServer().getInfo() ) )
+                    if ( request.isRetry() && def != null && ( getServer() == null || def != getServer().getInfo() ) )
                     {
                         sendMessage( bungee.getTranslation( "fallback_lobby" ) );
                         connect( def, null, true, ServerConnectEvent.Reason.LOBBY_FALLBACK );
@@ -339,7 +363,7 @@ public void operationComplete(ChannelFuture future) throws Exception
                 .channel( PipelineUtils.getChannel() )
                 .group( ch.getHandle().eventLoop() )
                 .handler( initializer )
-                .option( ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000 ) // TODO: Configurable
+                .option( ChannelOption.CONNECT_TIMEOUT_MILLIS, request.getConnectTimeout() )
                 .remoteAddress( target.getAddress() );
         // Windows is bugged, multi homed users will just have to live with random connecting IPs
         if ( getPendingConnection().getListener().isSetLocalAddress() && !PlatformDependent.isWindows() )