Implement event system scaffolding

api/src/main/java/com/bartlomiejpluta/base/api/entity/Entity.java

@@ -1,6 +1,7 @@
 package com.bartlomiejpluta.base.api.entity;
 
 import com.bartlomiejpluta.base.api.animation.Animated;
+import com.bartlomiejpluta.base.api.event.Reactive;
 import com.bartlomiejpluta.base.api.map.layer.object.ObjectLayer;
 import com.bartlomiejpluta.base.api.move.Direction;
 import com.bartlomiejpluta.base.api.move.Movable;
@@ -9,7 +10,7 @@ import com.bartlomiejpluta.base.internal.render.Renderable;
 
 import java.util.concurrent.CompletableFuture;
 
-public interface Entity extends Movable, Animated, Renderable, Updatable {
+public interface Entity extends Reactive, Movable, Animated, Renderable, Updatable {
 
    Direction getFaceDirection();
 

api/src/main/java/com/bartlomiejpluta/base/api/entity/EntityStepInListener.java

@@ -1,7 +0,0 @@
-package com.bartlomiejpluta.base.api.entity;
-
-import com.bartlomiejpluta.base.api.move.Movement;
-
-public interface EntityStepInListener extends Entity {
-   void onEntityStepIn(Movement movement, Entity entity);
-}

api/src/main/java/com/bartlomiejpluta/base/api/entity/EntityStepOutListener.java

@@ -1,7 +0,0 @@
-package com.bartlomiejpluta.base.api.entity;
-
-import com.bartlomiejpluta.base.api.move.Movement;
-
-public interface EntityStepOutListener extends Entity {
-   void onEntityStepOut(Movement movement, Entity entity);
-}

api/src/main/java/com/bartlomiejpluta/base/api/event/Event.java

@@ -0,0 +1,5 @@
+package com.bartlomiejpluta.base.api.event;
+
+public interface Event {
+   EventType<? extends Event> getType();
+}

api/src/main/java/com/bartlomiejpluta/base/api/event/EventType.java

@@ -0,0 +1,10 @@
+package com.bartlomiejpluta.base.api.event;
+
+import lombok.EqualsAndHashCode;
+import lombok.RequiredArgsConstructor;
+
+@EqualsAndHashCode
+@RequiredArgsConstructor
+public final class EventType<E extends Event> {
+   private final String type;
+}

api/src/main/java/com/bartlomiejpluta/base/api/event/Reactive.java

@@ -0,0 +1,11 @@
+package com.bartlomiejpluta.base.api.event;
+
+import java.util.function.Consumer;
+
+public interface Reactive {
+   <E extends Event> void handleEvent(E event);
+
+   <E extends Event> void addEventListener(EventType<E> type, Consumer<E> listener);
+
+   <E extends Event> void removeEventListener(EventType<E> type, Consumer<E> listener);
+}

api/src/main/java/com/bartlomiejpluta/base/api/map/layer/object/ObjectLayer.java

@@ -1,6 +1,7 @@
 package com.bartlomiejpluta.base.api.map.layer.object;
 
 import com.bartlomiejpluta.base.api.entity.Entity;
+import com.bartlomiejpluta.base.api.event.Event;
 import com.bartlomiejpluta.base.api.map.layer.base.Layer;
 import com.bartlomiejpluta.base.api.move.Movement;
 import org.joml.Vector2ic;
@@ -24,8 +25,5 @@ public interface ObjectLayer extends Layer {
 
    void pushMovement(Movement movement);
 
-   // Notifiers
-   void notifyEntityStepIn(Movement movement, Entity entity);
-
-   void notifyEntityStepOut(Movement movement, Entity entity);
+   void fireEvent(Event event);
 }

api/src/main/java/com/bartlomiejpluta/base/api/move/EntityMovement.java

@@ -27,7 +27,7 @@ public final class EntityMovement implements Movement {
    public boolean perform() {
       var result = object.move(this);
       if (result) {
-         object.getLayer().notifyEntityStepOut(this, object);
+         object.getLayer().fireEvent(new MoveEvent(MoveEvent.Action.BEGIN, object, this));
       }
 
       return result;
@@ -40,6 +40,6 @@ public final class EntityMovement implements Movement {
 
    @Override
    public void onFinish() {
-      object.getLayer().notifyEntityStepIn(this, object);
+      object.getLayer().fireEvent(new MoveEvent(MoveEvent.Action.END, object, this));
    }
 }

api/src/main/java/com/bartlomiejpluta/base/api/move/MoveEvent.java

@@ -0,0 +1,23 @@
+package com.bartlomiejpluta.base.api.move;
+
+import com.bartlomiejpluta.base.api.event.Event;
+import com.bartlomiejpluta.base.api.event.EventType;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public final class MoveEvent implements Event {
+   public enum Action {BEGIN, END}
+
+   private final Action action;
+   private final Movable movable;
+   private final Movement movement;
+
+   @Override
+   public EventType<? extends Event> getType() {
+      return TYPE;
+   }
+
+   public static EventType<MoveEvent> TYPE = new EventType<>("MOVE_EVENT");
+}

api/src/main/java/com/bartlomiejpluta/base/lib/entity/EntityDelegate.java

@@ -2,6 +2,8 @@ package com.bartlomiejpluta.base.lib.entity;
 
 import com.bartlomiejpluta.base.api.camera.Camera;
 import com.bartlomiejpluta.base.api.entity.Entity;
+import com.bartlomiejpluta.base.api.event.Event;
+import com.bartlomiejpluta.base.api.event.EventType;
 import com.bartlomiejpluta.base.api.map.layer.object.ObjectLayer;
 import com.bartlomiejpluta.base.api.move.Direction;
 import com.bartlomiejpluta.base.api.move.EntityMovement;
@@ -14,6 +16,7 @@ import org.joml.Vector2fc;
 import org.joml.Vector2ic;
 
 import java.util.concurrent.CompletableFuture;
+import java.util.function.Consumer;
 
 public abstract class EntityDelegate implements Entity {
    protected final Entity entity;
@@ -267,6 +270,21 @@ public abstract class EntityDelegate implements Entity {
       entity.setZIndex(zIndex);
    }
 
+   @Override
+   public <E extends Event> void handleEvent(E event) {
+      entity.handleEvent(event);
+   }
+
+   @Override
+   public <E extends Event> void addEventListener(EventType<E> type, Consumer<E> listener) {
+      entity.addEventListener(type, listener);
+   }
+
+   @Override
+   public <E extends Event> void removeEventListener(EventType<E> type, Consumer<E> listener) {
+      entity.removeEventListener(type, listener);
+   }
+
    @Override
    public CompletableFuture<Void> performInstantAnimation() {
       return entity.performInstantAnimation();