title packet

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ClientPlaySessionHandler.java

@@ -368,7 +368,7 @@ public class ClientPlaySessionHandler implements MinecraftSessionHandler {
     // Clear any title from the previous server.
     if (player.getProtocolVersion().gte(MINECRAFT_1_8)) {
       player.getConnection()
-          .delayedWrite(TitlePacket.resetForProtocolVersion(player.getProtocolVersion()));
+          .delayedWrite(TitlePacket.reset(player.getProtocolVersion()));
     }
 
     // Flush everything

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -50,7 +50,6 @@ import com.velocitypowered.proxy.protocol.util.PluginMessageUtil;
 import com.velocitypowered.proxy.server.VelocityRegisteredServer;
 import com.velocitypowered.proxy.tablist.VelocityTabList;
 import com.velocitypowered.proxy.tablist.VelocityTabListLegacy;
-import com.velocitypowered.proxy.util.DurationUtils;
 import com.velocitypowered.proxy.util.collect.CappedSet;
 import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
@@ -247,11 +246,10 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     ProtocolVersion playerVersion = getProtocolVersion();
     if (playerVersion.gte(ProtocolVersion.MINECRAFT_1_11)) {
       // Use the title packet instead.
-      TitlePacket pkt = new TitlePacket();
-      pkt.setAction(TitlePacket.SET_ACTION_BAR);
-      pkt.setComponent(ProtocolUtils.getJsonChatSerializer(playerVersion)
-          .serialize(message));
-      connection.write(pkt);
+      connection.write(new TitlePacket(
+          TitlePacket.SET_ACTION_BAR,
+          ProtocolUtils.getJsonChatSerializer(playerVersion).serialize(message)
+      ));
     } else {
       // Due to issues with action bar packets, we'll need to convert the text message into a
       // legacy message and then inject the legacy text into a component... yuck!
@@ -270,36 +268,32 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     GsonComponentSerializer serializer = ProtocolUtils.getJsonChatSerializer(this
         .getProtocolVersion());
 
-    TitlePacket titlePkt = new TitlePacket();
-    titlePkt.setAction(TitlePacket.SET_TITLE);
-    titlePkt.setComponent(serializer.serialize(title.title()));
-    connection.delayedWrite(titlePkt);
+    connection.delayedWrite(new TitlePacket(
+        TitlePacket.SET_TITLE,
+        serializer.serialize(title.title())
+    ));
 
-    TitlePacket subtitlePkt = new TitlePacket();
-    subtitlePkt.setAction(TitlePacket.SET_SUBTITLE);
-    subtitlePkt.setComponent(serializer.serialize(title.subtitle()));
-    connection.delayedWrite(subtitlePkt);
+    connection.delayedWrite(new TitlePacket(
+        TitlePacket.SET_SUBTITLE,
+        serializer.serialize(title.subtitle())
+    ));
 
-    TitlePacket timesPkt = TitlePacket.timesForProtocolVersion(this.getProtocolVersion());
     net.kyori.adventure.title.Title.Times times = title.times();
     if (times != null) {
-      timesPkt.setFadeIn((int) DurationUtils.toTicks(times.fadeIn()));
-      timesPkt.setStay((int) DurationUtils.toTicks(times.stay()));
-      timesPkt.setFadeOut((int) DurationUtils.toTicks(times.fadeOut()));
+      connection.delayedWrite(TitlePacket.times(this.getProtocolVersion(), times));
     }
-    connection.delayedWrite(timesPkt);
 
     connection.flush();
   }
 
   @Override
   public void clearTitle() {
-    connection.write(TitlePacket.hideForProtocolVersion(this.getProtocolVersion()));
+    connection.write(TitlePacket.hide(this.getProtocolVersion()));
   }
 
   @Override
   public void resetTitle() {
-    connection.write(TitlePacket.resetForProtocolVersion(this.getProtocolVersion()));
+    connection.write(TitlePacket.reset(this.getProtocolVersion()));
   }
 
   @Override

proxy/src/main/java/com/velocitypowered/proxy/protocol/StateRegistry.java

@@ -210,7 +210,7 @@ public enum StateRegistry {
           map(0x53, MINECRAFT_1_14, true),
           map(0x54, MINECRAFT_1_15, true),
           map(0x53, MINECRAFT_1_16, true));
-      clientbound.register(TitlePacket.class, TitlePacket::new,
+      clientbound.registerNew(TitlePacket.class, TitlePacket.DECODER,
           map(0x45, MINECRAFT_1_8, true),
           map(0x45, MINECRAFT_1_9, true),
           map(0x47, MINECRAFT_1_12, true),
@@ -416,7 +416,8 @@ public enum StateRegistry {
         return supplier.get();
       }
 
-      public @Nullable Packet decodePacket(final int id, ByteBuf buf, ProtocolDirection direction, ProtocolVersion protocolVersion) {
+      public @Nullable Packet decodePacket(final int id, ByteBuf buf, ProtocolDirection direction,
+                                           ProtocolVersion protocolVersion) {
         final Packet.Decoder<? extends Packet> decoder = this.packetIdToDecoder.get(id);
         if (decoder == null) {
           return null;

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/TitlePacket.java

@@ -1,34 +1,95 @@
 package com.velocitypowered.proxy.protocol.packet;
 
+import com.google.common.primitives.Ints;
 import com.velocitypowered.api.network.ProtocolVersion;
 import com.velocitypowered.proxy.connection.MinecraftSessionHandler;
 import com.velocitypowered.proxy.protocol.Packet;
 import com.velocitypowered.proxy.protocol.ProtocolDirection;
 import com.velocitypowered.proxy.protocol.ProtocolUtils;
+import com.velocitypowered.proxy.util.DurationUtils;
 import io.netty.buffer.ByteBuf;
+import java.util.Arrays;
+import net.kyori.adventure.title.Title;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 public class TitlePacket implements Packet {
 
+  public static final Decoder<TitlePacket> DECODER = (buf, direction, version) -> {
+    throw new UnsupportedOperationException();
+  };
+
+  public static TitlePacket hide(final ProtocolVersion version) {
+    return version.gte(ProtocolVersion.MINECRAFT_1_11)
+      ? Instances.HIDE
+      : Instances.HIDE_OLD;
+  }
+
+  public static TitlePacket reset(final ProtocolVersion version) {
+    return version.gte(ProtocolVersion.MINECRAFT_1_11)
+      ? Instances.RESET
+      : Instances.RESET_OLD;
+  }
+
+  public static TitlePacket times(final ProtocolVersion version, final Title.Times times) {
+    final int action = version.gte(ProtocolVersion.MINECRAFT_1_11)
+      ? SET_TIMES
+      : SET_TIMES_OLD;
+    return new TitlePacket(
+      action,
+      (int) DurationUtils.toTicks(times.fadeIn()),
+      (int) DurationUtils.toTicks(times.stay()),
+      (int) DurationUtils.toTicks(times.fadeOut())
+    );
+  }
+
   public static final int SET_TITLE = 0;
   public static final int SET_SUBTITLE = 1;
   public static final int SET_ACTION_BAR = 2;
   public static final int SET_TIMES = 3;
-  public static final int SET_TIMES_OLD = 2;
   public static final int HIDE = 4;
-  public static final int HIDE_OLD = 3;
   public static final int RESET = 5;
+
+  public static final int SET_TIMES_OLD = 2;
+  public static final int HIDE_OLD = 3;
   public static final int RESET_OLD = 4;
 
-  private int action;
-  private @Nullable String component;
-  private int fadeIn;
-  private int stay;
-  private int fadeOut;
+  private final int action;
+  private final @Nullable String component;
+  private final int fadeIn;
+  private final int stay;
+  private final int fadeOut;
 
-  @Override
-  public void decode(ByteBuf buf, ProtocolDirection direction, ProtocolVersion version) {
-    throw new UnsupportedOperationException(); // encode only
+  private TitlePacket(final int action) {
+    checkAction(action, HIDE, RESET, HIDE_OLD, RESET_OLD);
+    this.action = action;
+    this.component = null;
+    this.fadeIn = -1;
+    this.stay = -1;
+    this.fadeOut = -1;
+  }
+
+  public TitlePacket(final int action, final String component) {
+    checkAction(action, SET_TITLE, SET_SUBTITLE, SET_ACTION_BAR);
+    this.action = action;
+    this.component = component;
+    this.fadeIn = -1;
+    this.stay = -1;
+    this.fadeOut = -1;
+  }
+
+  public TitlePacket(final int action, final int fadeIn, final int stay, final int fadeOut) {
+    checkAction(action, SET_TIMES, SET_TIMES_OLD);
+    this.action = action;
+    this.component = null;
+    this.fadeIn = fadeIn;
+    this.stay = stay;
+    this.fadeOut = fadeOut;
+  }
+
+  private static void checkAction(final int action, final int... validActions) {
+    if (!Ints.contains(validActions, action)) {
+      throw new IllegalArgumentException("Invalid action " + action + ", expected one of: " + Arrays.toString(validActions));
+    }
   }
 
   @Override
@@ -79,67 +140,31 @@ public class TitlePacket implements Packet {
     }
   }
 
-  public int getAction() {
-    return action;
+  @Override
+  public boolean handle(MinecraftSessionHandler handler) {
+    return handler.handle(this);
   }
 
-  public void setAction(int action) {
-    this.action = action;
+  public int getAction() {
+    return action;
   }
 
   public @Nullable String getComponent() {
     return component;
   }
 
-  public void setComponent(@Nullable String component) {
-    this.component = component;
-  }
-
   public int getFadeIn() {
     return fadeIn;
   }
 
-  public void setFadeIn(int fadeIn) {
-    this.fadeIn = fadeIn;
-  }
-
   public int getStay() {
     return stay;
   }
 
-  public void setStay(int stay) {
-    this.stay = stay;
-  }
-
   public int getFadeOut() {
     return fadeOut;
   }
 
-  public void setFadeOut(int fadeOut) {
-    this.fadeOut = fadeOut;
-  }
-
-  public static TitlePacket hideForProtocolVersion(ProtocolVersion version) {
-    TitlePacket packet = new TitlePacket();
-    packet.setAction(version.gte(ProtocolVersion.MINECRAFT_1_11) ? TitlePacket.HIDE
-        : TitlePacket.HIDE_OLD);
-    return packet;
-  }
-
-  public static TitlePacket resetForProtocolVersion(ProtocolVersion version) {
-    TitlePacket packet = new TitlePacket();
-    packet.setAction(version.gte(ProtocolVersion.MINECRAFT_1_11) ? TitlePacket.RESET
-        : TitlePacket.RESET_OLD);
-    return packet;
-  }
-
-  public static TitlePacket timesForProtocolVersion(ProtocolVersion version) {
-    TitlePacket packet = new TitlePacket();
-    packet.setAction(version.gte(ProtocolVersion.MINECRAFT_1_11) ? TitlePacket.SET_TIMES
-        : TitlePacket.SET_TIMES_OLD);
-    return packet;
-  }
-
   @Override
   public String toString() {
     return "TitlePacket{"
@@ -151,8 +176,14 @@ public class TitlePacket implements Packet {
       + '}';
   }
 
-  @Override
-  public boolean handle(MinecraftSessionHandler handler) {
-    return handler.handle(this);
+  public static final class Instances {
+    public static final TitlePacket HIDE = new TitlePacket(TitlePacket.HIDE);
+    public static final TitlePacket RESET = new TitlePacket(TitlePacket.RESET);
+
+    public static final TitlePacket HIDE_OLD = new TitlePacket(TitlePacket.HIDE_OLD);
+    public static final TitlePacket RESET_OLD = new TitlePacket(TitlePacket.RESET_OLD);
+
+    private Instances() {
+    }
   }
 }