Allow to change despawnInPeaceful (#12880)

paper-api/src/main/java/org/bukkit/entity/Mob.java

@@ -1,25 +1,63 @@
 package org.bukkit.entity;
 
+import com.destroystokyo.paper.entity.Pathfinder;
+import io.papermc.paper.entity.Leashable;
+import net.kyori.adventure.util.TriState;
+import org.bukkit.Location;
 import org.bukkit.Sound;
+import org.bukkit.inventory.EntityEquipment;
+import org.bukkit.loot.LootTable;
 import org.bukkit.loot.Lootable;
-import org.jetbrains.annotations.NotNull;
+import org.jspecify.annotations.NullMarked;
-import org.jetbrains.annotations.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Represents a Mob. Mobs are living entities with simple AI.
  */
-public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Leashable { // Paper - Leashable API
+@NullMarked
+public interface Mob extends LivingEntity, Lootable, Leashable {
+
+    /**
+     * Check if a mob should be despawned when the world is set to peaceful difficulty.
+     * This also takes the {@link Mob#getDespawnInPeacefulOverride()} into account.
+     *
+     * @return True if the entity should be removed in peaceful
+     */
+    boolean shouldDespawnInPeaceful();
+
+    /**
+     * Sets if the entity should be despawned when the game is set to peaceful difficulty.
+     * <ul>
+     *     <li>{@link TriState#NOT_SET} – Use the default behavior for the entity</li>
+     *     <li>{@link TriState#TRUE} – The entity will be removed in Peaceful difficulty</li>
+     *     <li>{@link TriState#FALSE} – The entity will not automatically be removed in Peaceful difficulty</li>
+     * </ul>
+     *
+     * @param state a TriState representing the state of the override
+     */
+    void setDespawnInPeacefulOverride(TriState state);
+
+    /**
+     * Gets the current override value for whether this entity should despawn in peaceful difficulty.
+     * <ul>
+     *     <li>{@link TriState#NOT_SET} – Use the default behavior for the entity</li>
+     *     <li>{@link TriState#TRUE} – The entity will be removed in Peaceful difficulty</li>
+     *     <li>{@link TriState#FALSE} – The entity will not automatically be removed in Peaceful difficulty</li>
+     * </ul>
+     *
+     * @return a TriState representing the state of the override
+     * @see Mob#setDespawnInPeacefulOverride(TriState)
+     */
+    TriState getDespawnInPeacefulOverride();
 
-    // Paper start
     @Override
-    org.bukkit.inventory.@org.jetbrains.annotations.NotNull EntityEquipment getEquipment();
+    EntityEquipment getEquipment();
 
     /**
      * Enables access to control the pathing of an Entity
      * @return Pathfinding Manager for this entity
      */
-    @NotNull
+    Pathfinder getPathfinder();
-    com.destroystokyo.paper.entity.Pathfinder getPathfinder();
 
     /**
      * Check if this mob is exposed to daylight
@@ -35,7 +73,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      *
      * @param location location to look at
      */
-    void lookAt(@NotNull org.bukkit.Location location);
+    void lookAt(Location location);
 
     /**
      * Instruct this Mob to look at a specific Location
@@ -46,7 +84,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      * @param headRotationSpeed head rotation speed
      * @param maxHeadPitch max head pitch rotation
      */
-    void lookAt(@NotNull org.bukkit.Location location, float headRotationSpeed, float maxHeadPitch);
+    void lookAt(Location location, float headRotationSpeed, float maxHeadPitch);
 
     /**
      * Instruct this Mob to look at a specific Entity
@@ -57,7 +95,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      *
      * @param entity entity to look at
      */
-    void lookAt(@NotNull Entity entity);
+    void lookAt(Entity entity);
 
     /**
      * Instruct this Mob to look at a specific Entity
@@ -70,7 +108,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      * @param headRotationSpeed head rotation speed
      * @param maxHeadPitch max head pitch rotation
      */
-    void lookAt(@NotNull Entity entity, float headRotationSpeed, float maxHeadPitch);
+    void lookAt(Entity entity, float headRotationSpeed, float maxHeadPitch);
 
     /**
      * Instruct this Mob to look at a specific position
@@ -109,7 +147,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      * @return the max head pitch rotation
      */
     int getMaxHeadPitch();
-    // Paper end
+
     /**
      * Instructs this Mob to set the specified LivingEntity as its target.
      * <p>
@@ -118,26 +156,25 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      *
      * @param target New LivingEntity to target, or null to clear the target
      */
-    public void setTarget(@Nullable LivingEntity target);
+    void setTarget(@Nullable LivingEntity target);
 
     /**
      * Gets the current target of this Mob
      *
      * @return Current target of this creature, or null if none exists
      */
-    @Nullable
+    @Nullable LivingEntity getTarget();
-    public LivingEntity getTarget();
 
     /**
      * Sets whether this mob is aware of its surroundings.
-     *
+     * <p>
      * Unaware mobs will still move if pushed, attacked, etc. but will not move
      * or perform any actions on their own. Unaware mobs may also have other
      * unspecified behaviours disabled, such as drowning.
      *
      * @param aware whether the mob is aware
      */
-    public void setAware(boolean aware);
+    void setAware(boolean aware);
 
     /**
      * Gets whether this mob is aware of its surroundings.
@@ -148,7 +185,7 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      *
      * @return whether the mob is aware
      */
-    public boolean isAware();
+    boolean isAware();
 
     /**
      * Get the {@link Sound} this mob makes while ambiently existing. This sound
@@ -160,18 +197,14 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      *
      * @return the ambient sound, or null if this entity is ambiently quiet
      */
-    @Nullable
+    @Nullable Sound getAmbientSound();
-    public Sound getAmbientSound();
 
-    // Paper start - LootTable API
     @Override
-    default void setLootTable(final @Nullable org.bukkit.loot.LootTable table, final long seed) {
+    default void setLootTable(final @Nullable LootTable table, final long seed) {
         this.setLootTable(table);
         this.setSeed(seed);
     }
-    // Paper end - LootTable API
 
-    // Paper start - Missing Entity API
     /**
      * Some mobs will raise their arm(s) when aggressive:
      * <ul>
@@ -203,30 +236,25 @@ public interface Mob extends LivingEntity, Lootable, io.papermc.paper.entity.Lea
      * @see #isAggressive()
      */
     void setAggressive(boolean aggressive);
-    // Paper end - Missing Entity API
 
-    // Paper start - left-handed API
     /**
      * Check if Mob is left-handed
      *
      * @return True if left-handed
      */
-    public boolean isLeftHanded();
+    boolean isLeftHanded();
 
     /**
       * Set if Mob is left-handed
       *
       * @param leftHanded True if left-handed
       */
-    public void setLeftHanded(boolean leftHanded);
+    void setLeftHanded(boolean leftHanded);
-    // Paper end - left-handed API
 
-    // Paper start - mob xp reward API
     /**
      * Gets the amount of experience the mob will possibly drop. This value is randomized and it can give different results
      *
      * @return the amount of experience the mob will possibly drop
      */
-    public int getPossibleExperienceReward();
+    int getPossibleExperienceReward();
-    // Paper end - mob xp reward API
 }

paper-server/patches/features/0003-Entity-Activation-Range-2.0.patch

@@ -484,7 +484,7 @@ index c70a58f5f633fa8e255f74c42f5e87c96b7b013a..ec20a5a6d7c8f65abda528fec36bec7b
      public void tick() {
          super.tick();
 diff --git a/net/minecraft/world/entity/Entity.java b/net/minecraft/world/entity/Entity.java
-index 75f81a6bc156a6455a616b8de0d7701fd2255a2d..b3d951670b3a097d04cfe347d7df496b1d0a0e09 100644
+index b9f0745cdc42a093b69f46e353b99adf0c5aac56..a5d65e1b31e2e43cf039b8a19286a5324a739bbe 100644
 --- a/net/minecraft/world/entity/Entity.java
 +++ b/net/minecraft/world/entity/Entity.java
 @@ -409,6 +409,15 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
@@ -543,7 +543,7 @@ index 75f81a6bc156a6455a616b8de0d7701fd2255a2d..b3d951670b3a097d04cfe347d7df496b
              movement = this.maybeBackOffFromEdge(movement, type);
              Vec3 vec3 = this.collide(movement);
 diff --git a/net/minecraft/world/entity/LivingEntity.java b/net/minecraft/world/entity/LivingEntity.java
-index 13cf40918ead3e2cb2699398ac659a3e1806294b..1ba342a1a60951f828034d3ed535b577b3990bf6 100644
+index 8dd8a3d2a862998a920f226b2a6d9a877aac70a8..0c52e315557e1dae6a852694786e72241fff1e29 100644
 --- a/net/minecraft/world/entity/LivingEntity.java
 +++ b/net/minecraft/world/entity/LivingEntity.java
 @@ -3215,6 +3215,14 @@ public abstract class LivingEntity extends Entity implements Attackable, Waypoin
@@ -562,10 +562,10 @@ index 13cf40918ead3e2cb2699398ac659a3e1806294b..1ba342a1a60951f828034d3ed535b577
      public void tick() {
          super.tick();
 diff --git a/net/minecraft/world/entity/Mob.java b/net/minecraft/world/entity/Mob.java
-index 3047763580fabd069db5e90a9a854396c6243763..0470c4bbf8be7e48ce8dfa4910c3b9f5ebb23360 100644
+index c737fd87e804129fac95be7d19b4aafab38d8b94..21c6d4746c6a905ec312dc1e35535cbd13868322 100644
 --- a/net/minecraft/world/entity/Mob.java
 +++ b/net/minecraft/world/entity/Mob.java
-@@ -206,6 +206,19 @@ public abstract class Mob extends LivingEntity implements EquipmentUser, Leashab
+@@ -207,6 +207,19 @@ public abstract class Mob extends LivingEntity implements EquipmentUser, Leashab
          return this.lookControl;
      }
  

paper-server/patches/sources/net/minecraft/world/entity/Mob.java.patch

@@ -23,11 +23,12 @@
      public GoalSelector targetSelector;
      @Nullable
      private LivingEntity target;
-@@ -129,6 +_,7 @@
+@@ -129,6 +_,8 @@
      private Leashable.LeashData leashData;
      private BlockPos homePosition = BlockPos.ZERO;
      private int homeRadius = -1;
 +    public boolean aware = true; // CraftBukkit
++    public net.kyori.adventure.util.TriState despawnInPeacefulOverride = net.kyori.adventure.util.TriState.NOT_SET; // Paper - allow changing despawnInPeaceful
  
      protected Mob(EntityType<? extends Mob> entityType, Level level) {
          super(entityType, level);
@@ -84,11 +85,16 @@
      }
  
      @Override
-@@ -365,13 +_,22 @@
+@@ -365,13 +_,27 @@
          if (this.isNoAi()) {
              output.putBoolean("NoAI", this.isNoAi());
          }
 +        output.putBoolean("Bukkit.Aware", this.aware); // CraftBukkit
++        // Paper start - allow changing despawnInPeaceful
++        if (this.despawnInPeacefulOverride != net.kyori.adventure.util.TriState.NOT_SET) {
++            output.putString("Paper.DespawnInPeacefulOverride", this.despawnInPeacefulOverride.name());
++        }
++        // Paper end - allow changing despawnInPeaceful
      }
  
      @Override
@@ -109,11 +115,12 @@
          this.dropChances = input.read("drop_chances", DropChances.CODEC).orElse(DropChances.DEFAULT);
          this.readLeashData(input);
          this.homeRadius = input.getIntOr("home_radius", -1);
-@@ -383,6 +_,7 @@
+@@ -383,6 +_,8 @@
          this.lootTable = input.read("DeathLootTable", LootTable.KEY_CODEC);
          this.lootTableSeed = input.getLongOr("DeathLootTableSeed", 0L);
          this.setNoAi(input.getBooleanOr("NoAI", false));
 +        this.aware = input.getBooleanOr("Bukkit.Aware", true); // CraftBukkit
++        this.despawnInPeacefulOverride = input.read("Paper.DespawnInPeacefulOverride", io.papermc.paper.util.PaperCodecs.TRI_STATE_CODEC).orElse(net.kyori.adventure.util.TriState.NOT_SET); // Paper - allow changing despawnInPeaceful
      }
  
      @Override
@@ -176,11 +183,25 @@
                  }
  
                  ItemStack itemStack = equipmentSlotForItem.limit(stack);
-@@ -608,22 +_,29 @@
+@@ -601,29 +_,42 @@
+         return this.isPassenger();
+     }
+ 
++    // Paper start - allow changing despawnInPeaceful
++    public final boolean shouldActuallyDespawnInPeaceful() {
++        return this.despawnInPeacefulOverride.toBooleanOrElse(this.shouldDespawnInPeaceful());
++    }
++    // Paper end - allow changing despawnInPeaceful
++
+     protected boolean shouldDespawnInPeaceful() {
+         return false;
+     }
+ 
      @Override
      public void checkDespawn() {
-         if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldDespawnInPeaceful()) {
+-        if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldDespawnInPeaceful()) {
 -            this.discard();
++        if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldActuallyDespawnInPeaceful()) { //Paper - allow changing despawnInPeaceful
 +            this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
          } else if (!this.isPersistenceRequired() && !this.requiresCustomPersistence()) {
 -            Entity nearestPlayer = this.level().getNearestPlayer(this, -1.0);

paper-server/patches/sources/net/minecraft/world/entity/boss/wither/WitherBoss.java.patch

@@ -95,8 +95,9 @@
  
      @Override
      public void checkDespawn() {
-         if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldDespawnInPeaceful()) {
+-        if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldDespawnInPeaceful()) {
 -            this.discard();
++        if (this.level().getDifficulty() == Difficulty.PEACEFUL && this.shouldActuallyDespawnInPeaceful()) { //Paper - allow changing despawnInPeaceful
 +            this.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
          } else {
              this.noActionTime = 0;

paper-server/src/main/java/io/papermc/paper/util/PaperCodecs.java

@@ -15,6 +15,7 @@ import io.papermc.paper.registry.TypedKey;
 import java.util.Optional;
 import java.util.function.Function;
 import net.kyori.adventure.key.Key;
+import net.kyori.adventure.util.TriState;
 import net.minecraft.core.Holder;
 import net.minecraft.resources.RegistryOps;
 import org.bukkit.Keyed;
@@ -24,6 +25,14 @@ import org.jspecify.annotations.NullMarked;
 @NullMarked
 public final class PaperCodecs {
 
+    public static final Codec<TriState> TRI_STATE_CODEC = Codec.STRING.comapFlatMap(s -> {
+        try {
+            return DataResult.success(TriState.valueOf(s));
+        } catch (Exception e) {
+            return DataResult.error(() -> "Unknown TriState value: " + s);
+        }
+    }, TriState::name);
+
     /**
      * This codec is lenient on decoding and encoding compared to native OptionalFieldCodec
      * which only has options to be lenient on decoding.

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftMob.java

@@ -2,6 +2,7 @@ package org.bukkit.craftbukkit.entity;
 
 import com.google.common.base.Preconditions;
 import java.util.Optional;
+import net.kyori.adventure.util.TriState;
 import net.minecraft.sounds.SoundEvent;
 import org.bukkit.Sound;
 import org.bukkit.craftbukkit.CraftLootTable;
@@ -20,6 +21,22 @@ public abstract class CraftMob extends CraftLivingEntity implements Mob, io.pape
         this.paperPathfinder = new com.destroystokyo.paper.entity.PaperPathfinder(entity); // Paper - Mob Pathfinding API
     }
 
+    @Override
+    public boolean shouldDespawnInPeaceful() {
+        return this.getHandle().shouldActuallyDespawnInPeaceful();
+    }
+
+    @Override
+    public void setDespawnInPeacefulOverride(final TriState state) {
+        Preconditions.checkArgument(state != null, "TriState cannot be null");
+        this.getHandle().despawnInPeacefulOverride = state;
+    }
+
+    @Override
+    public TriState getDespawnInPeacefulOverride() {
+        return this.getHandle().despawnInPeacefulOverride;
+    }
+
     @Override
     public net.minecraft.world.entity.Mob getHandle() {
         return (net.minecraft.world.entity.Mob) this.entity;