Implement triggers for the new ScoreboardTagsChangeEvent

Author: Tmpod

paper-server/patches/features/0034-Implement-calling-ScoreboardTagsChangeEvent.patch

@@ -0,0 +1,60 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: tmpod <[email protected]>
+Date: Fri, 19 Sep 2025 17:36:10 +0100
+Subject: [PATCH] Implement calling ScoreboardTagsChangeEvent
+
+This is a new event added in commit c3e62c81 of Paper's API.
+
+diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
+index 9a102b2c58446bd0aac5bd7f00e647f0270e7983..670e964d78b899f9a3ce2154106a03ac49884ab3 100644
+--- a/net/minecraft/world/entity/Entity.java
++++ b/net/minecraft/world/entity/Entity.java
+@@ -2,7 +2,6 @@ package net.minecraft.world.entity;
+ 
+ import com.google.common.collect.ImmutableList;
+ import com.google.common.collect.Lists;
+-import com.google.common.collect.Sets;
+ import com.google.common.collect.ImmutableList.Builder;
+ import com.mojang.logging.LogUtils;
+ import com.mojang.serialization.Codec;
+@@ -627,11 +626,23 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+     }
+ 
+     public boolean addTag(String tag) {
+-        return this.tags.add(tag); // Paper - fully limit tag size - replace set impl
++        // Paper start - add ScoreboardTagsChangeEvent
++        final var event = org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this, tag, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.ADD);
++        if (!event.isCancelled()) {
++            return this.tags.add(tag); // Paper - fully limit tag size - replace set impl
++        }
++        return false;
++        // Paper end - add ScoreboardTagsChangeEvent
+     }
+ 
+     public boolean removeTag(String tag) {
+-        return this.tags.remove(tag);
++        // Paper start - add ScoreboardTagsChangeEvent
++        final var event = org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this, tag, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.REMOVE);
++        if (!event.isCancelled()) {
++            return this.tags.remove(tag);
++        }
++        return false;
++        // Paper end - add ScoreboardTagsChangeEvent
+     }
+ 
+     public void kill(ServerLevel level) {
+@@ -2644,7 +2655,13 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+                 // Paper end
+                 this.customData = input.read("data", CustomData.CODEC).orElse(CustomData.EMPTY);
+                 this.tags.clear();
+-                input.read("Tags", TAG_LIST_CODEC).ifPresent(this.tags::addAll);
++                // Paper start - add ScoreboardTagsChangeEvent
++                input.read("Tags", TAG_LIST_CODEC).ifPresent( tags -> {
++                    final var event = org.bukkit.craftbukkit.event.CraftEventFactory.callScoreboardTagsChangeEvent(this, tags, io.papermc.paper.event.entity.ScoreboardTagsChangeEvent.Change.SET);
++                    if (!event.isCancelled())
++                        this.tags.addAll(tags);
++                });
++                // Paper end - add ScoreboardTagsChangeEvent
+                 this.readAdditionalSaveData(input);
+                 if (this.repositionEntityAfterLoad()) {
+                     this.reapplyPosition();