Add boss bar implementations

src/main/java/net/minestom/server/MinecraftServer.java

@@ -1,6 +1,7 @@
 package net.minestom.server;
 
 import net.minestom.server.advancements.AdvancementManager;
+import net.minestom.server.adventure.BossBarManager;
 import net.minestom.server.benchmark.BenchmarkManager;
 import net.minestom.server.command.CommandManager;
 import net.minestom.server.data.DataManager;
@@ -115,6 +116,7 @@ public final class MinecraftServer {
     private static DimensionTypeManager dimensionTypeManager;
     private static BiomeManager biomeManager;
     private static AdvancementManager advancementManager;
+    private static BossBarManager bossBarManager;
 
     private static ExtensionManager extensionManager;
 
@@ -180,6 +182,7 @@ public final class MinecraftServer {
         dimensionTypeManager = new DimensionTypeManager();
         biomeManager = new BiomeManager();
         advancementManager = new AdvancementManager();
+        bossBarManager = new BossBarManager();
 
         updateManager = new UpdateManager();
 
@@ -427,6 +430,16 @@ public final class MinecraftServer {
         return connectionManager;
     }
 
+    /**
+     * Gets the boss bar manager.
+     *
+     * @return the boss bar manager
+     */
+    public static BossBarManager getBossBarManager() {
+        checkInitStatus(bossBarManager);
+        return bossBarManager;
+    }
+
     /**
      * Gets the object handling the client packets processing.
      * <p>

src/main/java/net/minestom/server/adventure/BossBarManager.java

@@ -0,0 +1,223 @@
+package net.minestom.server.adventure;
+
+import com.google.common.collect.MapMaker;
+import net.kyori.adventure.bossbar.BossBar;
+import net.kyori.adventure.bossbar.BossBar.*;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.serializer.gson.GsonComponentSerializer;
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.entity.Player;
+import net.minestom.server.event.GlobalEventHandler;
+import net.minestom.server.event.player.PlayerDisconnectEvent;
+import net.minestom.server.network.packet.server.play.BossBarPacket;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.jetbrains.annotations.NotNull;
+
+import javax.swing.*;
+import java.util.*;
+import java.util.function.Consumer;
+import java.util.logging.Handler;
+
+import static net.minestom.server.network.packet.server.play.BossBarPacket.Action.*;
+
+/**
+ * Manages all boss bars known to this Minestom instance. This implementation is heavily
+ * based on <a href="https://github.com/VelocityPowered/Velocity">Velocity</a>'s
+ * boss bar management system.
+ */
+public class BossBarManager implements BossBar.Listener {
+    private final Map<BossBar, Holder> bars;
+
+    /**
+     * Creates a new boss bar manager.
+     */
+    public BossBarManager() {
+        this.bars = new MapMaker().weakKeys().makeMap();
+
+        MinecraftServer.getGlobalEventHandler().addEventCallback(PlayerDisconnectEvent.class, this::onDisconnect);
+    }
+
+    /**
+     * Adds the specified player to the boss bar's viewers and spawns the boss bar, registering the
+     * boss bar if needed.
+     *
+     * @param player the intended viewer
+     * @param bar the boss bar to show
+     */
+    public void addBossBar(@NotNull Player player, @NotNull BossBar bar) {
+        Holder holder = this.getOrCreateHandler(bar);
+
+        if (holder.players.add(player.getUuid())) {
+            player.getPlayerConnection().sendPacket(holder.createAddPacket());
+        }
+    }
+    /**
+     * Removes the specified player from the boss bar's viewers and despawns the boss bar.
+     *
+     * @param player the intended viewer
+     * @param bar the boss bar to hide
+     */
+
+    public void removeBossBar(@NotNull Player player, @NotNull BossBar bar) {
+        Holder holder = this.getOrCreateHandler(bar);
+
+        if (holder.players.remove(player.getUuid())) {
+            player.getPlayerConnection().sendPacket(holder.createRemovePacket());
+        }
+    }
+
+    @Override
+    public void bossBarNameChanged(@NonNull BossBar bar, @NonNull Component oldName, @NonNull Component newName) {
+        Holder holder = this.bars.get(bar);
+        this.updatePlayers(holder.createTitleUpdate(newName), holder.players);
+    }
+
+    @Override
+    public void bossBarProgressChanged(@NonNull BossBar bar, float oldProgress, float newProgress) {
+        Holder holder = this.bars.get(bar);
+        this.updatePlayers(holder.createPercentUpdate(newProgress), holder.players);
+    }
+
+    @Override
+    public void bossBarColorChanged(@NonNull BossBar bar, @NonNull Color oldColor, @NonNull Color newColor) {
+        Holder holder = this.bars.get(bar);
+        this.updatePlayers(holder.createColorUpdate(newColor), holder.players);
+    }
+
+    @Override
+    public void bossBarOverlayChanged(@NonNull BossBar bar, BossBar.@NonNull Overlay oldOverlay, BossBar.@NonNull Overlay newOverlay) {
+        Holder holder = this.bars.get(bar);
+        this.updatePlayers(holder.createOverlayUpdate(newOverlay), holder.players);
+    }
+
+    @Override
+    public void bossBarFlagsChanged(@NonNull BossBar bar, @NonNull Set<BossBar.Flag> flagsAdded, @NonNull Set<BossBar.Flag> flagsRemoved) {
+        Holder holder = this.bars.get(bar);
+        this.updatePlayers(holder.createFlagsUpdate(), holder.players);
+    }
+
+    /**
+     * Sends the packet to all players in the set, removing them if they no longer exist
+     * in the connection manager.
+     *
+     * @param packet the packet
+     * @param players the players
+     */
+    private void updatePlayers(BossBarPacket packet, Set<UUID> players) {
+        Iterator<UUID> iterator = players.iterator();
+
+        while (iterator.hasNext()) {
+            Player player = MinecraftServer.getConnectionManager().getPlayer(iterator.next());
+
+            if (player == null) {
+                iterator.remove();
+            } else {
+                player.getPlayerConnection().sendPacket(packet);
+            }
+        }
+    }
+
+    /**
+     * Gets or creates a handler for this bar.
+     *
+     * @param bar the bar
+     *
+     * @return the handler
+     */
+    private @NotNull Holder getOrCreateHandler(@NotNull BossBar bar) {
+        Holder holder = this.bars.computeIfAbsent(bar, Holder::new);
+
+        if (!holder.registered) {
+            bar.addListener(this);
+            holder.registered = true;
+        }
+
+        return holder;
+    }
+
+    /**
+     * Called when a player disconnects. This removes the player from any boss bars they
+     * may be subscribed to.
+     *
+     * @param event the event
+     */
+    private void onDisconnect(@NotNull PlayerDisconnectEvent event) {
+        for (Holder holder : this.bars.values()) {
+            holder.players.remove(event.getPlayer().getUuid());
+        }
+    }
+
+    private static class Holder {
+        protected final UUID uuid;
+        protected final BossBar bar;
+        protected final Set<UUID> players;
+        protected boolean registered;
+
+        Holder(@NotNull BossBar bar) {
+            this.uuid = UUID.randomUUID();
+            this.bar = bar;
+            this.players = Collections.newSetFromMap(new MapMaker().weakKeys().makeMap());
+            this.registered = false;
+        }
+
+        BossBarPacket createRemovePacket() {
+            return this.createGenericPacket(REMOVE, packet -> {});
+        }
+
+        BossBarPacket createAddPacket() {
+            return this.createGenericPacket(ADD, packet -> {
+                packet.title = GsonComponentSerializer.gson().serialize(bar.name());
+                packet.color = bar.color().ordinal();
+                packet.division = bar.overlay().ordinal();
+                packet.health = bar.progress();
+                packet.flags = serializeFlags(bar.flags());
+            });
+        }
+
+        BossBarPacket createPercentUpdate(float newPercent) {
+            return this.createGenericPacket(UPDATE_HEALTH, packet -> packet.health = newPercent);
+        }
+
+        BossBarPacket createColorUpdate(@NotNull Color color) {
+            return this.createGenericPacket(UPDATE_STYLE, packet -> {
+                packet.color = color.ordinal();
+                packet.division = bar.overlay().ordinal();
+            });
+        }
+
+        BossBarPacket createTitleUpdate(@NotNull Component title) {
+            return this.createGenericPacket(UPDATE_TITLE, packet -> packet.title = GsonComponentSerializer.gson().serialize(title));
+        }
+
+        BossBarPacket createFlagsUpdate() {
+            return createFlagsUpdate(bar.flags());
+        }
+
+        BossBarPacket createFlagsUpdate(@NotNull Set<Flag> newFlags) {
+            return this.createGenericPacket(UPDATE_FLAGS, packet -> packet.flags = serializeFlags(bar.flags()));
+        }
+
+        BossBarPacket createOverlayUpdate(@NotNull Overlay overlay) {
+            return this.createGenericPacket(UPDATE_STYLE, packet -> {
+                packet.division = overlay.ordinal();
+                packet.color = bar.color().ordinal();
+            });
+        }
+
+        BossBarPacket createGenericPacket(@NotNull BossBarPacket.Action action, @NotNull Consumer<BossBarPacket> consumer) {
+            BossBarPacket packet = new BossBarPacket();
+            packet.uuid = this.uuid;
+            packet.action = action;
+            consumer.accept(packet);
+            return packet;
+        }
+
+        private static byte serializeFlags(@NotNull Set<Flag> flags) {
+            byte val = 0x0;
+            for (Flag flag : flags) {
+                val |= flag.ordinal();
+            }
+            return val;
+        }
+    }
+}

src/main/java/net/minestom/server/bossbar/BarColor.java

@@ -2,7 +2,9 @@ package net.minestom.server.bossbar;
 
 /**
  * Represents the displayed color of a {@link BossBar}.
+ * @deprecated Use {@link net.kyori.adventure.bossbar.BossBar}
  */
+@Deprecated
 public enum BarColor {
     PINK,
     BLUE,

src/main/java/net/minestom/server/bossbar/BarDivision.java

@@ -2,7 +2,10 @@ package net.minestom.server.bossbar;
 
 /**
  * Used to define the number of segments on a {@link BossBar}.
+ *
+ * @deprecated Use {@link net.kyori.adventure.bossbar.BossBar}
  */
+@Deprecated
 public enum BarDivision {
     SOLID,
     SEGMENT_6,

src/main/java/net/minestom/server/bossbar/BossBar.java

@@ -19,7 +19,10 @@ import java.util.concurrent.CopyOnWriteArraySet;
  * and add the {@link Player} you want using {@link #addViewer(Player)} and remove them using {@link #removeViewer(Player)}.
  * <p>
  * You can retrieve all the boss bars of a {@link Player} with {@link #getBossBars(Player)}.
+ *
+ * @deprecated Use {@link net.kyori.adventure.audience.Audience#showBossBar(net.kyori.adventure.bossbar.BossBar)}
  */
+@Deprecated
 public class BossBar implements Viewable {
 
     private static final int MAX_BOSSBAR = 7;
@@ -249,10 +252,10 @@ public class BossBar implements Viewable {
         BossBarPacket bossBarPacket = new BossBarPacket();
         bossBarPacket.uuid = uuid;
         bossBarPacket.action = BossBarPacket.Action.ADD;
-        bossBarPacket.title = title;
+        bossBarPacket.title = title.toString();
         bossBarPacket.health = progress;
-        bossBarPacket.color = color;
+        bossBarPacket.color = color.ordinal();
-        bossBarPacket.division = division;
+        bossBarPacket.division = division.ordinal();
         bossBarPacket.flags = flags;
         player.getPlayerConnection().sendPacket(bossBarPacket);
     }
@@ -275,7 +278,7 @@ public class BossBar implements Viewable {
         BossBarPacket bossBarPacket = new BossBarPacket();
         bossBarPacket.uuid = uuid;
         bossBarPacket.action = BossBarPacket.Action.UPDATE_TITLE;
-        bossBarPacket.title = title;
+        bossBarPacket.title = title.toString();
         sendPacketToViewers(bossBarPacket);
     }
 
@@ -291,7 +294,7 @@ public class BossBar implements Viewable {
         BossBarPacket bossBarPacket = new BossBarPacket();
         bossBarPacket.uuid = uuid;
         bossBarPacket.action = BossBarPacket.Action.UPDATE_STYLE;
-        bossBarPacket.color = color;
+        bossBarPacket.color = color.ordinal();
         sendPacketToViewers(bossBarPacket);
     }
 }

src/main/java/net/minestom/server/entity/Player.java

@@ -2,6 +2,7 @@ package net.minestom.server.entity;
 
 import com.google.common.collect.Queues;
 import net.kyori.adventure.audience.MessageType;
+import net.kyori.adventure.bossbar.BossBar;
 import net.kyori.adventure.identity.Identity;
 import net.kyori.adventure.inventory.Book;
 import net.kyori.adventure.text.Component;
@@ -12,8 +13,10 @@ import net.kyori.adventure.title.Title;
 import net.minestom.server.MinecraftServer;
 import net.minestom.server.advancements.AdvancementTab;
 import net.minestom.server.attribute.Attribute;
+import net.minestom.server.attribute.AttributeInstance;
 import net.minestom.server.bossbar.BossBar;
 import net.minestom.server.chat.ChatParser;
+import net.minestom.server.attribute.Attributes;
 import net.minestom.server.chat.ColoredText;
 import net.minestom.server.chat.JsonMessage;
 import net.minestom.server.chat.RichMessage;
@@ -561,9 +564,9 @@ public class Player extends LivingEntity implements CommandSender {
 
         // Boss bars cache
         {
-            Set<BossBar> bossBars = BossBar.getBossBars(this);
+            Set<net.minestom.server.bossbar.BossBar> bossBars = net.minestom.server.bossbar.BossBar.getBossBars(this);
             if (bossBars != null) {
-                for (BossBar bossBar : bossBars) {
+                for (net.minestom.server.bossbar.BossBar bossBar : bossBars) {
                     bossBar.removeViewer(this);
                 }
             }
@@ -1091,6 +1094,16 @@ public class Player extends LivingEntity implements CommandSender {
         playerConnection.sendPacket(titlePacket);
     }
 
+    @Override
+    public void showBossBar(@NonNull BossBar bar) {
+        MinecraftServer.getBossBarManager().addBossBar(this, bar);
+    }
+
+    @Override
+    public void hideBossBar(@NonNull BossBar bar) {
+        MinecraftServer.getBossBarManager().removeBossBar(this, bar);
+    }
+
     /**
      * Opens a book ui for the player with the given book metadata.
      *

src/main/java/net/minestom/server/network/packet/server/play/BossBarPacket.java

@@ -15,10 +15,10 @@ public class BossBarPacket implements ServerPacket {
     public UUID uuid;
     public Action action;
 
-    public JsonMessage title; // Only text
+    public String title;
     public float health;
-    public BarColor color;
+    public int color;
-    public BarDivision division;
+    public int division;
     public byte flags;
 
 
@@ -29,10 +29,10 @@ public class BossBarPacket implements ServerPacket {
 
         switch (action) {
             case ADD:
-                writer.writeSizedString(title.toString());
+                writer.writeSizedString(title);
                 writer.writeFloat(health);
-                writer.writeVarInt(color.ordinal());
+                writer.writeVarInt(color);
-                writer.writeVarInt(division.ordinal());
+                writer.writeVarInt(division);
                 writer.writeByte(flags);
                 break;
             case REMOVE:
@@ -42,11 +42,11 @@ public class BossBarPacket implements ServerPacket {
                 writer.writeFloat(health);
                 break;
             case UPDATE_TITLE:
-                writer.writeSizedString(title.toString());
+                writer.writeSizedString(title);
                 break;
             case UPDATE_STYLE:
-                writer.writeVarInt(color.ordinal());
+                writer.writeVarInt(color);
-                writer.writeVarInt(division.ordinal());
+                writer.writeVarInt(division);
                 break;
             case UPDATE_FLAGS:
                 writer.writeByte(flags);