EntityAIGroupBuilder

src/main/java/net/minestom/server/entity/ai/EntityAI.java

@@ -44,6 +44,15 @@ public interface EntityAI {
         addAIGroup(group);
     }
 
+    /**
+     * Creates new {@link EntityAIGroup} builder.
+     *
+     * @return a builder to create and add an {@link EntityAIGroup}.
+     */
+    default EntityAIGroupBuilder newAIGroupBuilder() {
+        return new EntityAIGroupBuilder(this);
+    }
+
     default void aiTick(long time) {
         getAIGroups().forEach(group -> group.tick(time));
     }

src/main/java/net/minestom/server/entity/ai/EntityAIGroupBuilder.java

@@ -0,0 +1,47 @@
+package net.minestom.server.entity.ai;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class EntityAIGroupBuilder {
+
+    private final EntityAI ai;
+    private final List<GoalSelector> goalSelectors = new ArrayList<>();
+    private final List<TargetSelector> targetSelectors = new ArrayList<>();
+
+    EntityAIGroupBuilder(EntityAI ai) {
+        this.ai = ai;
+    }
+
+    /**
+     * Adds {@link GoalSelector} to the list of goal selectors of the building {@link EntityAIGroup}.
+     * Addition order is also a priority: priority the higher the earlier selector was added.
+     *
+     * @param goalSelector goal selector to be added.
+     * @return this builder.
+     */
+    public EntityAIGroupBuilder addGoalSelector(GoalSelector goalSelector) {
+        this.goalSelectors.add(goalSelector);
+        return this;
+    }
+
+    /**
+     * Adds {@link TargetSelector} to the list of target selectors of the building {@link EntityAIGroup}.
+     * Addition order is also a priority: priority the higher the earlier selector was added.
+     *
+     * @param targetSelector target selector to be added.
+     * @return this builder.
+     */
+    public EntityAIGroupBuilder addTargetSelector(TargetSelector targetSelector) {
+        this.targetSelectors.add(targetSelector);
+        return this;
+    }
+
+    /**
+     * Creates new {@link EntityAIGroup} and adds it to the owning {@link EntityAI} of this builder.
+     */
+    public void build() {
+        this.ai.addAIGroup(this.goalSelectors, this.targetSelectors);
+    }
+
+}

src/test/java/demo/entity/ChickenCreature.java

@@ -3,12 +3,17 @@ package demo.entity;
 import com.google.common.collect.ImmutableList;
 import net.minestom.server.attribute.Attributes;
 import net.minestom.server.entity.LivingEntity;
+import net.minestom.server.entity.ai.goal.DoNothingGoal;
+import net.minestom.server.entity.ai.goal.MeleeAttackGoal;
 import net.minestom.server.entity.ai.goal.RandomStrollGoal;
+import net.minestom.server.entity.ai.target.ClosestEntityTarget;
+import net.minestom.server.entity.ai.target.LastEntityDamagerTarget;
 import net.minestom.server.entity.damage.DamageType;
 import net.minestom.server.entity.type.animal.EntityChicken;
 import net.minestom.server.event.entity.EntityAttackEvent;
 import net.minestom.server.utils.Position;
 import net.minestom.server.utils.Vector;
+import net.minestom.server.utils.time.TimeUnit;
 
 public class ChickenCreature extends EntityChicken {
 
@@ -27,6 +32,15 @@ public class ChickenCreature extends EntityChicken {
                 )
         );
 
+        // Another way to register previously added EntityAIGroup, using specialized builder:
+//        newAIGroupBuilder()
+//                .addGoalSelector(new DoNothingGoal(this, 500, .1F))
+//                .addGoalSelector(new MeleeAttackGoal(this, 500, 2, TimeUnit.MILLISECOND))
+//                .addGoalSelector(new RandomStrollGoal(this, 2))
+//                .addTargetSelector(new LastEntityDamagerTarget(this, 15))
+//                .addTargetSelector(new ClosestEntityTarget(this, 15, LivingEntity.class))
+//                .build();
+
         getAttribute(Attributes.MOVEMENT_SPEED).setBaseValue(0.1f);
 
         addEventCallback(EntityAttackEvent.class, event -> {

src/test/java/demo/entity/ZombieCreature.java

@@ -11,11 +11,8 @@ public class ZombieCreature extends EntityZombie {
 
     public ZombieCreature(Position spawnPosition) {
         super(spawnPosition);
-        addAIGroup(
-                ImmutableList.of(
-                        new RandomLookAroundGoal(this, 20)
-                ),
-                Collections.emptyList()
-        );
+        newAIGroupBuilder()
+                .addGoalSelector(new RandomLookAroundGoal(this, 20))
+                .build();
     }
 }