Local node support (#688)

src/main/java/net/minestom/server/entity/Entity.java

@@ -15,9 +15,13 @@ import net.minestom.server.coordinate.Pos;
 import net.minestom.server.coordinate.Vec;
 import net.minestom.server.entity.metadata.EntityMeta;
 import net.minestom.server.event.EventDispatcher;
+import net.minestom.server.event.EventFilter;
+import net.minestom.server.event.EventHandler;
+import net.minestom.server.event.EventNode;
 import net.minestom.server.event.entity.*;
 import net.minestom.server.event.instance.AddEntityToInstanceEvent;
 import net.minestom.server.event.instance.RemoveEntityFromInstanceEvent;
+import net.minestom.server.event.trait.EntityEvent;
 import net.minestom.server.instance.Chunk;
 import net.minestom.server.instance.EntityTracker;
 import net.minestom.server.instance.Instance;
@@ -77,7 +81,7 @@ import java.util.function.UnaryOperator;
  * <p>
  * To create your own entity you probably want to extends {@link LivingEntity} or {@link EntityCreature} instead.
  */
-public class Entity implements Viewable, Tickable, Schedulable, Snapshotable, TagHandler, PermissionHandler, HoverEventSource<ShowEntity>, Sound.Emitter {
+public class Entity implements Viewable, Tickable, Schedulable, Snapshotable, EventHandler<EntityEvent>, TagHandler, PermissionHandler, HoverEventSource<ShowEntity>, Sound.Emitter {
 
     private static final Int2ObjectSyncMap<Entity> ENTITY_BY_ID = Int2ObjectSyncMap.hashmap();
     private static final Map<UUID, Entity> ENTITY_BY_UUID = new ConcurrentHashMap<>();
@@ -143,6 +147,7 @@ public class Entity implements Viewable, Tickable, Schedulable, Snapshotable, Ta
     protected final Set<Player> viewers = viewEngine.set;
     private final MutableNBTCompound nbtCompound = new MutableNBTCompound();
     private final Scheduler scheduler = Scheduler.newScheduler();
+    private final EventNode<EntityEvent> eventNode = EventNode.type(toString(), EventFilter.ENTITY);
     private final Set<Permission> permissions = new CopyOnWriteArraySet<>();
 
     protected UUID uuid;
@@ -1543,6 +1548,12 @@ public class Entity implements Viewable, Tickable, Schedulable, Snapshotable, Ta
                 TagReadable.fromCompound(nbtCompound.toCompound()));
     }
 
+    @Override
+    @ApiStatus.Experimental
+    public @NotNull EventNode<EntityEvent> eventNode() {
+        return eventNode;
+    }
+
     /**
      * Applies knockback to the entity
      *

src/main/java/net/minestom/server/event/EventHandler.java

@@ -0,0 +1,13 @@
+package net.minestom.server.event;
+
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Represents an element which can have {@link Event} listeners assigned to it.
+ */
+@ApiStatus.Experimental
+@ApiStatus.NonExtendable
+public interface EventHandler<T extends Event> {
+    @NotNull EventNode<T> eventNode();
+}

src/main/java/net/minestom/server/event/EventNodeImpl.java

@@ -20,11 +20,11 @@ import java.util.function.Consumer;
 non-sealed class EventNodeImpl<T extends Event> implements EventNode<T> {
     private static final Object GLOBAL_CHILD_LOCK = new Object();
 
-    private final ClassValue<Handle<T>> handleMap = new ClassValue<>() {
+    private final ClassValue<ListenerHandle<T>> handleMap = new ClassValue<>() {
         @Override
-        protected Handle<T> computeValue(Class<?> type) {
+        protected ListenerHandle<T> computeValue(Class<?> type) {
             //noinspection unchecked
-            return new Handle<>((Class<T>) type);
+            return createHandle((Class<T>) type);
         }
     };
     private final Map<Class<? extends T>, ListenerEntry<T>> listenerMap = new ConcurrentHashMap<>();
@@ -47,6 +47,10 @@ non-sealed class EventNodeImpl<T extends Event> implements EventNode<T> {
         this.eventType = filter.eventType();
     }
 
+    protected @NotNull ListenerHandle<T> createHandle(@NotNull Class<T> listenerType) {
+        return new Handle<>(listenerType);
+    }
+
     @Override
     @SuppressWarnings("unchecked")
     public <E extends T> @NotNull ListenerHandle<E> getHandle(@NotNull Class<E> handleType) {
@@ -307,7 +311,7 @@ non-sealed class EventNodeImpl<T extends Event> implements EventNode<T> {
     }
 
     @SuppressWarnings("unchecked")
-    final class Handle<E extends Event> implements ListenerHandle<E> {
+    non-sealed class Handle<E extends Event> implements ListenerHandle<E> {
         private static final VarHandle UPDATED;
 
         static {

src/main/java/net/minestom/server/event/GlobalEventHandler.java

@@ -2,7 +2,7 @@ package net.minestom.server.event;
 
 import org.jetbrains.annotations.NotNull;
 
-import java.util.function.Consumer;
+import java.util.List;
 
 /**
  * Object containing all the global event listeners.
@@ -12,12 +12,34 @@ public final class GlobalEventHandler extends EventNodeImpl<Event> {
         super("global", EventFilter.ALL, null);
     }
 
-    /**
-     * @deprecated use {@link #addListener(Class, Consumer)}
-     */
-    @Deprecated
-    public <V extends Event> boolean addEventCallback(@NotNull Class<V> eventClass, @NotNull EventCallback<V> eventCallback) {
-        addListener(eventClass, eventCallback::run);
-        return true;
+    @Override
+    protected @NotNull ListenerHandle<Event> createHandle(@NotNull Class<Event> listenerType) {
+        return new GlobalHandle<>(listenerType);
+    }
+
+    @SuppressWarnings("unchecked")
+    final class GlobalHandle<E extends Event> extends Handle<E> {
+        // Represents the filters where the handler has a node
+        private static final List<EventFilter<?, ?>> HANDLER_FILTERS = List.of(EventFilter.ENTITY);
+        // Local nodes handling
+        private final EventFilter<E, EventHandler<? super E>>[] localFilters;
+
+        GlobalHandle(Class<E> eventType) {
+            super(eventType);
+            // Filters with EventHandler support
+            this.localFilters = (EventFilter<E, EventHandler<? super E>>[]) HANDLER_FILTERS.stream()
+                    .filter(filter -> filter.eventType().isAssignableFrom(eventType)).toArray(EventFilter[]::new);
+        }
+
+        @Override
+        public void call(@NotNull E event) {
+            // Per-handler listeners
+            for (var filter : localFilters) {
+                var handle = filter.getHandler(event);
+                if (handle != null) handle.eventNode().call(event);
+            }
+            // Global listeners
+            super.call(event);
+        }
     }
 }

src/main/java/net/minestom/server/event/handler/EventHandler.java

@@ -1,27 +0,0 @@
-package net.minestom.server.event.handler;
-
-import net.minestom.server.event.Event;
-import net.minestom.server.event.EventCallback;
-import net.minestom.server.event.EventNode;
-import org.jetbrains.annotations.ApiStatus;
-import org.jetbrains.annotations.NotNull;
-
-/**
- * Represents an element which can have {@link Event} listeners assigned to it.
- * <p>
- * Use {@link EventNode} directly.
- */
-@Deprecated
-public interface EventHandler<T extends Event> {
-
-    @ApiStatus.Internal
-    @Deprecated(forRemoval = true)
-    @NotNull EventNode<T> getEventNode();
-
-    @Deprecated
-    default <V extends T> boolean addEventCallback(@NotNull Class<V> eventClass, @NotNull EventCallback<V> eventCallback) {
-        var node = getEventNode();
-        node.addListener(eventClass, eventCallback::run);
-        return true;
-    }
-}

src/test/java/net/minestom/server/event/EventNodeTest.java

@@ -1,6 +1,9 @@
 package net.minestom.server.event;
 
+import net.minestom.server.entity.Entity;
+import net.minestom.server.entity.EntityType;
 import net.minestom.server.event.trait.CancellableEvent;
+import net.minestom.server.event.trait.EntityEvent;
 import net.minestom.server.event.trait.ItemEvent;
 import net.minestom.server.event.trait.RecursiveEvent;
 import net.minestom.server.item.ItemStack;
@@ -45,6 +48,13 @@ public class EventNodeTest {
         }
     }
 
+    record EntityTestEvent(Entity entity) implements EntityEvent {
+        @Override
+        public @NotNull Entity getEntity() {
+            return entity;
+        }
+    }
+
     @Test
     public void testCall() {
         var node = EventNode.all("main");
@@ -234,4 +244,25 @@ public class EventNodeTest {
         node.call(new ItemTestEvent(item));
         assertFalse(result.get());
     }
+
+    @Test
+    public void entityLocal() {
+        var node = new GlobalEventHandler();
+        var entity = new Entity(EntityType.ZOMBIE);
+
+        AtomicBoolean result = new AtomicBoolean(false);
+        var listener = EventListener.of(EntityTestEvent.class, event -> result.set(true));
+        entity.eventNode().addListener(listener);
+
+        assertFalse(result.get());
+
+        node.call(new EntityTestEvent(entity));
+        assertTrue(result.get());
+
+        result.set(false);
+        entity.eventNode().removeListener(listener);
+
+        node.call(new EntityTestEvent(entity));
+        assertFalse(result.get());
+    }
 }