Add ItemModifierAddEvent

Author: Malfrador

papyrus-server/minecraft-patches/sources/net/minecraft/world/entity/LivingEntity.java.patch

@@ -1,17 +1,20 @@
 --- a/net/minecraft/world/entity/LivingEntity.java
 +++ b/net/minecraft/world/entity/LivingEntity.java
-@@ -11,6 +_,8 @@
+@@ -11,6 +_,9 @@
  import com.mojang.serialization.DataResult;
  import com.mojang.serialization.Dynamic;
  import com.mojang.serialization.JavaOps;
 +import de.erethon.papyrus.CraftPDamageType;
++import de.erethon.papyrus.events.ItemModifierAddEvent;
 +import io.papermc.paper.event.entity.EntityKnockbackEvent;
  import it.unimi.dsi.fastutil.doubles.DoubleDoubleImmutablePair;
  import it.unimi.dsi.fastutil.objects.Reference2ObjectArrayMap;
  import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
-@@ -138,17 +_,16 @@
+@@ -137,18 +_,18 @@
+ import net.minecraft.world.scores.Scoreboard;
  import net.minecraft.world.waypoints.Waypoint;
  import net.minecraft.world.waypoints.WaypointTransmitter;
++import org.bukkit.craftbukkit.attribute.CraftAttributeInstance;
  import org.jetbrains.annotations.Contract;
 +import org.bukkit.Bukkit;
 +import org.bukkit.craftbukkit.damage.CraftDamageSource;
@@ -216,3 +219,18 @@
 
      public float applyItemBlocking(ServerLevel level, DamageSource damageSource, float damageAmount) {
          // Paper start
+@@ -3418,7 +_,13 @@
+                         AttributeInstance instance = this.attributes.getInstance(holder);
+                         if (instance != null) {
+                             instance.removeModifier(attributeModifier.id());
+-                            instance.addTransientModifier(attributeModifier);
++                            // Papyrus start - Add modifier event
++                            ItemModifierAddEvent event = new ItemModifierAddEvent(getBukkitLivingEntity(), CraftItemStack.asCraftMirror(itemBySlot), CraftAttributeInstance.convert(attributeModifier));
++                            event.callEvent();
++                            if (!event.isCancelled()) {
++                                instance.addTransientModifier(CraftAttributeInstance.convert(event.getAttributeModifier()));
++                            }
++                            // Papyrus end
+                         }
+                     });
+                     if (this.level() instanceof ServerLevel serverLevel) {

papyrus-server/src/main/java/de/erethon/papyrus/events/ItemModifierAddEvent.java

@@ -0,0 +1,59 @@
+package de.erethon.papyrus.events;
+
+import org.bukkit.attribute.AttributeModifier;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+import org.bukkit.inventory.ItemStack;
+
+public class ItemModifierAddEvent extends Event implements Cancellable {
+
+    private static final HandlerList handlers = new HandlerList();
+
+    private LivingEntity living;
+    private ItemStack stack;
+    private AttributeModifier modifier;
+    private boolean cancelled = false;
+
+    public ItemModifierAddEvent(LivingEntity living, ItemStack stack, AttributeModifier modifier) {
+        this.living = living;
+        this.stack =  stack;
+        this.modifier = modifier;
+    }
+
+    public LivingEntity getLivingEntity() {
+        return living;
+    }
+
+    public ItemStack getItemStack() {
+        return stack;
+    }
+
+    public AttributeModifier getAttributeModifier() {
+        return modifier;
+    }
+
+    public void setAttributeModifier(AttributeModifier modifier) {
+        this.modifier = modifier;
+    }
+
+    @Override
+    public HandlerList getHandlers() {
+        return handlers;
+    }
+
+    public static HandlerList getHandlerList() {
+        return handlers;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return cancelled;
+    }
+
+    @Override
+    public void setCancelled(boolean cancel) {
+        cancelled = cancel;
+    }
+}