Code/net/minecraft/server/level/ServerBossEvent.java

package net.minecraft.server.level;

import com.google.common.base.Objects;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import java.util.function.Function;
import net.minecraft.network.chat.Component;
import net.minecraft.network.protocol.game.ClientboundBossEventPacket;
import net.minecraft.util.Mth;
import net.minecraft.world.BossEvent;

public class ServerBossEvent extends BossEvent {
    private final Set<ServerPlayer> players = Sets.newHashSet();
    private final Set<ServerPlayer> unmodifiablePlayers = Collections.unmodifiableSet(this.players);
    private boolean visible = true;

    public ServerBossEvent(Component p_8300_, BossEvent.BossBarColor p_8301_, BossEvent.BossBarOverlay p_8302_) {
        super(Mth.createInsecureUUID(), p_8300_, p_8301_, p_8302_);
    }

    @Override
    public void setProgress(float p_143223_) {
        if (p_143223_ != this.progress) {
            super.setProgress(p_143223_);
            this.broadcast(ClientboundBossEventPacket::createUpdateProgressPacket);
        }
    }

    @Override
    public void setColor(BossEvent.BossBarColor p_8307_) {
        if (p_8307_ != this.color) {
            super.setColor(p_8307_);
            this.broadcast(ClientboundBossEventPacket::createUpdateStylePacket);
        }
    }

    @Override
    public void setOverlay(BossEvent.BossBarOverlay p_8309_) {
        if (p_8309_ != this.overlay) {
            super.setOverlay(p_8309_);
            this.broadcast(ClientboundBossEventPacket::createUpdateStylePacket);
        }
    }

    @Override
    public BossEvent setDarkenScreen(boolean p_8315_) {
        if (p_8315_ != this.darkenScreen) {
            super.setDarkenScreen(p_8315_);
            this.broadcast(ClientboundBossEventPacket::createUpdatePropertiesPacket);
        }

        return this;
    }

    @Override
    public BossEvent setPlayBossMusic(boolean p_8318_) {
        if (p_8318_ != this.playBossMusic) {
            super.setPlayBossMusic(p_8318_);
            this.broadcast(ClientboundBossEventPacket::createUpdatePropertiesPacket);
        }

        return this;
    }

    @Override
    public BossEvent setCreateWorldFog(boolean p_8320_) {
        if (p_8320_ != this.createWorldFog) {
            super.setCreateWorldFog(p_8320_);
            this.broadcast(ClientboundBossEventPacket::createUpdatePropertiesPacket);
        }

        return this;
    }

    @Override
    public void setName(Component p_8311_) {
        if (!Objects.equal(p_8311_, this.name)) {
            super.setName(p_8311_);
            this.broadcast(ClientboundBossEventPacket::createUpdateNamePacket);
        }
    }

    private void broadcast(Function<BossEvent, ClientboundBossEventPacket> p_143225_) {
        if (this.visible) {
            ClientboundBossEventPacket clientboundbosseventpacket = p_143225_.apply(this);

            for (ServerPlayer serverplayer : this.players) {
                serverplayer.connection.send(clientboundbosseventpacket);
            }
        }
    }

    public void addPlayer(ServerPlayer p_8305_) {
        if (this.players.add(p_8305_) && this.visible) {
            p_8305_.connection.send(ClientboundBossEventPacket.createAddPacket(this));
        }
    }

    public void removePlayer(ServerPlayer p_8316_) {
        if (this.players.remove(p_8316_) && this.visible) {
            p_8316_.connection.send(ClientboundBossEventPacket.createRemovePacket(this.getId()));
        }
    }

    public void removeAllPlayers() {
        if (!this.players.isEmpty()) {
            for (ServerPlayer serverplayer : Lists.newArrayList(this.players)) {
                this.removePlayer(serverplayer);
            }
        }
    }

    public boolean isVisible() {
        return this.visible;
    }

    public void setVisible(boolean p_8322_) {
        if (p_8322_ != this.visible) {
            this.visible = p_8322_;

            for (ServerPlayer serverplayer : this.players) {
                serverplayer.connection.send(p_8322_ ? ClientboundBossEventPacket.createAddPacket(this) : ClientboundBossEventPacket.createRemovePacket(this.getId()));
            }
        }
    }

    public Collection<ServerPlayer> getPlayers() {
        return this.unmodifiablePlayers;
    }
}