Trying to fix main hand on bungee, handle left handed on 1.8 using 0x80

bukkit/src/main/java/us/myles/ViaVersion/bukkit/platform/BukkitViaConfig.java

@@ -249,4 +249,9 @@ public class BukkitViaConfig extends Config implements ViaVersionConfig {
     public int get1_13TabCompleteDelay() {
         return getInt("1_13-tab-complete-delay", 0);
     }
+
+    @Override
+    public boolean isLeftHandedHandling() {
+        return getBoolean("left-handed-handling", true);
+    }
 }

bungee/src/main/java/us/myles/ViaVersion/bungee/listeners/MainHandPatch.java

@@ -1,51 +0,0 @@
-package us.myles.ViaVersion.bungee.listeners;
-
-import net.md_5.bungee.api.event.ServerConnectEvent;
-import net.md_5.bungee.api.plugin.Listener;
-import net.md_5.bungee.event.EventHandler;
-import us.myles.ViaVersion.api.Via;
-import us.myles.ViaVersion.api.data.UserConnection;
-import us.myles.ViaVersion.protocols.base.ProtocolInfo;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.EntityTracker;
-
-import java.lang.reflect.Method;
-
-/*
-    This solves the wrong mainhand issue when you join with BungeeCord on a 1.8 server, and switch to a 1.9 or higher.
- */
-public class MainHandPatch implements Listener {
-    private static Method getSettings = null;
-    private static Method setMainHand = null;
-
-    static {
-        try {
-            getSettings = Class.forName("net.md_5.bungee.UserConnection").getDeclaredMethod("getSettings");
-            setMainHand = Class.forName("net.md_5.bungee.protocol.packet.ClientSettings").getDeclaredMethod("setMainHand", int.class);
-        } catch (Exception ignored) {
-        }
-    }
-
-    @EventHandler
-    public void onServerConnect(ServerConnectEvent event) {
-        // Ignore if it doesn't exist (Like BungeeCord 1.8)
-        if (setMainHand == null || getSettings == null)
-            return;
-
-        UserConnection user = Via.getManager().getConnection(event.getPlayer().getUniqueId());
-        if (user == null) return;
-
-        try {
-            if (user.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {
-                Object settings = getSettings.invoke(event.getPlayer());
-                if (settings != null) {
-                    if (user.has(EntityTracker.class)) {
-                        setMainHand.invoke(settings, user.get(EntityTracker.class).getMainHand());
-                    }
-                }
-            }
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-}

bungee/src/main/java/us/myles/ViaVersion/bungee/platform/BungeeViaConfig.java

@@ -302,4 +302,9 @@ public class BungeeViaConfig extends Config implements ViaVersionConfig {
     public int get1_13TabCompleteDelay() {
         return getInt("1_13-tab-complete-delay", 0);
     }
+
+    @Override
+    public boolean isLeftHandedHandling() {
+        return getBoolean("left-handed-handling", true);
+    }
 }

bungee/src/main/java/us/myles/ViaVersion/bungee/platform/BungeeViaLoader.java

@@ -8,16 +8,13 @@ import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.platform.ViaPlatformLoader;
 import us.myles.ViaVersion.bungee.handlers.BungeeServerHandler;
 import us.myles.ViaVersion.bungee.listeners.ElytraPatch;
-import us.myles.ViaVersion.bungee.listeners.MainHandPatch;
 import us.myles.ViaVersion.bungee.listeners.UpdateListener;
-import us.myles.ViaVersion.bungee.providers.BungeeBossBarProvider;
-import us.myles.ViaVersion.bungee.providers.BungeeEntityIdProvider;
-import us.myles.ViaVersion.bungee.providers.BungeeMovementTransmitter;
-import us.myles.ViaVersion.bungee.providers.BungeeVersionProvider;
+import us.myles.ViaVersion.bungee.providers.*;
 import us.myles.ViaVersion.bungee.service.ProtocolDetectorService;
 import us.myles.ViaVersion.protocols.base.VersionProvider;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.BossBarProvider;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.EntityIdProvider;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.MainHandProvider;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.MovementTransmitterProvider;
 
 import java.util.HashSet;
@@ -45,7 +42,6 @@ public class BungeeViaLoader implements ViaPlatformLoader {
         registerListener(plugin);
         registerListener(new UpdateListener());
         registerListener(new BungeeServerHandler());
-        registerListener(new MainHandPatch());
         registerListener(new ElytraPatch());
 
         // Providers
@@ -53,6 +49,7 @@ public class BungeeViaLoader implements ViaPlatformLoader {
         Via.getManager().getProviders().use(VersionProvider.class, new BungeeVersionProvider());
         Via.getManager().getProviders().use(EntityIdProvider.class, new BungeeEntityIdProvider());
         Via.getManager().getProviders().use(BossBarProvider.class, new BungeeBossBarProvider());
+        Via.getManager().getProviders().use(MainHandProvider.class, new BungeeMainHandProvider());
 
         if (plugin.getConf().getBungeePingInterval() > 0) {
             tasks.add(plugin.getProxy().getScheduler().schedule(

bungee/src/main/java/us/myles/ViaVersion/bungee/providers/BungeeMainHandProvider.java

@@ -0,0 +1,42 @@
+package us.myles.ViaVersion.bungee.providers;
+
+import net.md_5.bungee.api.ProxyServer;
+import net.md_5.bungee.api.connection.ProxiedPlayer;
+import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.protocols.base.ProtocolInfo;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.MainHandProvider;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/*
+    This solves the wrong mainhand issue when you join with BungeeCord on a 1.8 server, and switch to a 1.9 or higher.
+ */
+public class BungeeMainHandProvider extends MainHandProvider {
+    private static Method getSettings = null;
+    private static Method setMainHand = null;
+
+    static {
+        try {
+            getSettings = Class.forName("net.md_5.bungee.UserConnection").getDeclaredMethod("getSettings");
+            setMainHand = Class.forName("net.md_5.bungee.protocol.packet.ClientSettings").getDeclaredMethod("setMainHand", int.class);
+        } catch (Exception ignored) {
+        }
+    }
+
+    @Override
+    public void setMainHand(UserConnection user, int hand) {
+        ProtocolInfo info = user.get(ProtocolInfo.class);
+        if (info == null || info.getUuid() == null) return;
+        ProxiedPlayer player = ProxyServer.getInstance().getPlayer(info.getUuid());
+        if (player == null) return;
+        try {
+            Object settings = getSettings.invoke(player);
+            if (settings != null) {
+                setMainHand.invoke(settings, hand);
+            }
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            e.printStackTrace();
+        }
+    }
+}

common/src/main/java/us/myles/ViaVersion/api/ViaVersionConfig.java

@@ -308,4 +308,9 @@ public interface ViaVersionConfig {
      * @return the delay in ticks
      */
     int get1_13TabCompleteDelay();
+
+    /**
+     * Handles left handed info by using unused bit 7 on Client Settings packet
+     */
+    boolean isLeftHandedHandling();
 }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/Protocol1_9TO1_8.java

@@ -95,6 +95,7 @@ public class Protocol1_9TO1_8 extends Protocol {
         providers.register(CommandBlockProvider.class, new CommandBlockProvider());
         providers.register(EntityIdProvider.class, new EntityIdProvider());
         providers.register(BossBarProvider.class, new BossBarProvider());
+        providers.register(MainHandProvider.class, new MainHandProvider());
         providers.require(MovementTransmitterProvider.class);
         if (Via.getConfig().isStimulatePlayerTick()) {
             Via.getPlatform().runRepeatingSync(new ViaIdleThread(), 1L);

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/EntityPackets.java

@@ -283,7 +283,7 @@ public class EntityPackets {
                     @Override
                     public void handle(PacketWrapper wrapper) throws Exception {
                         if (!Via.getConfig().isMinimizeCooldown()) return;
-                        if (wrapper.get(Type.VAR_INT, 0) != wrapper.user().get(EntityTracker.class).getEntityID()) {
+                        if (wrapper.get(Type.VAR_INT, 0) != wrapper.user().get(EntityTracker.class).getProvidedEntityId()) {
                             return;
                         }
                         int propertiesToRead = wrapper.read(Type.INT);

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/packets/PlayerPackets.java

@@ -19,6 +19,7 @@ import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.chat.ChatRewriter;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.chat.GameMode;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.CommandBlockProvider;
+import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.MainHandProvider;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.ClientChunks;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.EntityTracker;
 
@@ -458,8 +459,15 @@ public class PlayerPackets {
                     public void handle(PacketWrapper wrapper) throws Exception {
                         int hand = wrapper.read(Type.VAR_INT);
 
-                        EntityTracker tracker = wrapper.user().get(EntityTracker.class);
-                        tracker.setMainHand(hand);
+                        if (Via.getConfig().isLeftHandedHandling()) {
+                            // Add 0x80 if left handed
+                            if (hand == 0) wrapper.set(Type.UNSIGNED_BYTE, 0,
+                                    (short) (wrapper.get(Type.UNSIGNED_BYTE, 0).intValue() | 0x80)
+                            );
+                        }
+                        wrapper.sendToServer(Protocol1_9TO1_8.class, true, true);
+                        wrapper.cancel();
+                        Via.getManager().getProviders().get(MainHandProvider.class).setMainHand(wrapper.user(), hand);
                     }
                 });
             }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/providers/MainHandProvider.java

@@ -0,0 +1,9 @@
+package us.myles.ViaVersion.protocols.protocol1_9to1_8.providers;
+
+import us.myles.ViaVersion.api.data.UserConnection;
+import us.myles.ViaVersion.api.platform.providers.Provider;
+
+public class MainHandProvider implements Provider {
+    public void setMainHand(UserConnection user, int hand) {
+    }
+}

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_9to1_8/storage/EntityTracker.java

@@ -52,8 +52,6 @@ public class EntityTracker extends StoredObject {
     @Setter
     private GameMode gameMode;
     @Setter
-    private int mainHand;
-    @Setter
     private String currentTeam;
 
     public EntityTracker(UserConnection user) {
@@ -170,6 +168,13 @@ public class EntityTracker extends StoredObject {
                         }
                     }
                 }
+                if (metadata.getId() == 12 && Via.getConfig().isLeftHandedHandling()) { // Player model
+                    metadataList.add(new Metadata(
+                            13, // Main hand
+                            MetaType1_9.Byte,
+                            (byte) (((((byte) metadata.getValue()) & 0x80) != 0) ? 0 : 1)
+                    ));
+                }
             }
             if (type == Entity1_10Types.EntityType.ARMOR_STAND && Via.getConfig().isHologramPatch()) {
                 if (metadata.getId() == 0 && getMetaByIndex(metadataList, 10) != null) {

common/src/main/resources/assets/viaversion/config.yml

@@ -166,3 +166,5 @@ replacement-piston-id: 0
 force-json-transform: false
 # Minimize the cooldown animation in 1.8 servers
 minimize-cooldown: true
+# Left handed handling on 1.8 servers
+left-handed-handling: true

sponge/src/main/java/us/myles/ViaVersion/sponge/platform/SpongeViaConfig.java

@@ -255,4 +255,9 @@ public class SpongeViaConfig extends Config implements ViaVersionConfig {
     public int get1_13TabCompleteDelay() {
         return getInt("1_13-tab-complete-delay", 0);
     }
+
+    @Override
+    public boolean isLeftHandedHandling() {
+        return getBoolean("left-handed-handling", true);
+    }
 }

velocity/src/main/java/us/myles/ViaVersion/velocity/listeners/MainHandPatch.java

@@ -1,49 +0,0 @@
-package us.myles.ViaVersion.velocity.listeners;
-
-import com.velocitypowered.api.event.Subscribe;
-import com.velocitypowered.api.event.player.ServerConnectedEvent;
-import com.velocitypowered.api.proxy.player.PlayerSettings;
-import us.myles.ViaVersion.api.Via;
-import us.myles.ViaVersion.api.data.UserConnection;
-import us.myles.ViaVersion.protocols.base.ProtocolInfo;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9TO1_8;
-import us.myles.ViaVersion.protocols.protocol1_9to1_8.storage.EntityTracker;
-import us.myles.ViaVersion.util.ReflectionUtil;
-
-import java.lang.reflect.Method;
-
-/*
-    This solves the wrong mainhand issue when you join with BungeeCord on a 1.8 server, and switch to a 1.9 or higher.
- */
-public class MainHandPatch {
-    private static Method setSettings;
-
-    static {
-        try {
-            Class clientSettings = Class.forName("com.velocitypowered.proxy.protocol.packet.ClientSettings");
-            setSettings = Class.forName("com.velocitypowered.proxy.connection.client.ConnectedPlayer").getDeclaredMethod("setPlayerSettings", clientSettings);
-            setSettings.setAccessible(true);
-        } catch (ClassNotFoundException | NoSuchMethodException e) {
-            e.printStackTrace();
-        }
-    }
-
-    @Subscribe
-    public void onServerConnect(ServerConnectedEvent event) {
-        UserConnection user = Via.getManager().getConnection(event.getPlayer().getUniqueId());
-        if (user == null || setSettings == null) return;
-
-        try {
-            if (user.get(ProtocolInfo.class).getPipeline().contains(Protocol1_9TO1_8.class)) {
-                PlayerSettings settings = event.getPlayer().getPlayerSettings();
-                if (user.has(EntityTracker.class)) {
-                    Object clientSettings = ReflectionUtil.get(settings, "settings", Object.class);
-                    ReflectionUtil.set(clientSettings, "mainHand", user.get(EntityTracker.class).getMainHand());
-                    setSettings.invoke(event.getPlayer(), clientSettings);
-                }
-            }
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-}

velocity/src/main/java/us/myles/ViaVersion/velocity/platform/VelocityViaConfig.java

@@ -307,4 +307,9 @@ public class VelocityViaConfig extends Config implements ViaVersionConfig {
     public int get1_13TabCompleteDelay() {
         return getInt("1_13-tab-complete-delay", 0);
     }
+
+    @Override
+    public boolean isLeftHandedHandling() {
+        return getBoolean("left-handed-handling", true);
+    }
 }

velocity/src/main/java/us/myles/ViaVersion/velocity/platform/VelocityViaLoader.java

@@ -9,7 +9,6 @@ import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.BossBarProvider;
 import us.myles.ViaVersion.protocols.protocol1_9to1_8.providers.MovementTransmitterProvider;
 import us.myles.ViaVersion.velocity.handlers.VelocityServerHandler;
 import us.myles.ViaVersion.velocity.listeners.ElytraPatch;
-import us.myles.ViaVersion.velocity.listeners.MainHandPatch;
 import us.myles.ViaVersion.velocity.listeners.UpdateListener;
 import us.myles.ViaVersion.velocity.providers.VelocityBossBarProvider;
 import us.myles.ViaVersion.velocity.providers.VelocityMovementTransmitter;
@@ -26,10 +25,10 @@ public class VelocityViaLoader implements ViaPlatformLoader {
         Via.getManager().getProviders().use(BossBarProvider.class, new VelocityBossBarProvider());
         Via.getManager().getProviders().use(VersionProvider.class, new VelocityVersionProvider());
         // We probably don't need a EntityIdProvider because velocity sends a Join packet on server change
+        // We don't need main hand patch because Join Game packet makes client send hand data again
 
         VelocityPlugin.PROXY.getEventManager().register(plugin, new UpdateListener());
         VelocityPlugin.PROXY.getEventManager().register(plugin, new VelocityServerHandler());
-        VelocityPlugin.PROXY.getEventManager().register(plugin, new MainHandPatch());
         VelocityPlugin.PROXY.getEventManager().register(plugin, new ElytraPatch());
 
         int pingInterval = ((VelocityViaConfig) Via.getPlatform().getConf()).getVelocityPingInterval();