1 files changed, 69 insertions, 0 deletions
diff --git a/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentMapper.cs b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentMapper.cs
new file mode 100644
index 0000000..35b196c
--- /dev/null
+++ b/Plugins/MonoGame.Extended/source/MonoGame.Extended.Entities/ComponentMapper.cs
@@ -0,0 +1,69 @@
+using System;
+using MonoGame.Extended.Collections;
+
+namespace MonoGame.Extended.Entities
+{
+    public abstract class ComponentMapper
+    {
+        protected ComponentMapper(int id, Type componentType)
+        {
+            Id = id;
+            ComponentType = componentType;
+        }
+
+        public int Id { get; }
+        public Type ComponentType { get; }
+        public abstract bool Has(int entityId);
+        public abstract void Delete(int entityId);
+    }
+
+    public class ComponentMapper<T> : ComponentMapper
+        where T : class
+    {
+        public event Action<int> OnPut;
+        public event Action<int> OnDelete;
+
+        private readonly Action<int> _onCompositionChanged;
+
+        public ComponentMapper(int id, Action<int> onCompositionChanged)
+            : base(id, typeof(T))
+        {
+            _onCompositionChanged = onCompositionChanged;
+            Components = new Bag<T>();
+        }
+
+        public Bag<T> Components { get; }
+
+        public void Put(int entityId, T component)
+        {
+            Components[entityId] = component;
+            _onCompositionChanged(entityId);
+            OnPut?.Invoke(entityId);
+        }
+
+        public T Get(Entity entity)
+        {
+            return Get(entity.Id);
+        }
+
+        public T Get(int entityId)
+        {
+            return Components[entityId];
+        }
+
+        public override bool Has(int entityId)
+        {
+            if (entityId >= Components.Count)
+                return false;
+
+            return Components[entityId] != null;
+        }
+
+        public override void Delete(int entityId)
+        {
+            Components[entityId] = null;
+            _onCompositionChanged(entityId);
+            OnDelete?.Invoke(entityId);
+        }
+    }
+}