additional package setup

Packages/com.boxfriend.utils@58cc9986a36b/Runtime/Utils/SingletonBehaviour.cs

@@ -0,0 +1,40 @@
+using UnityEngine;
+
+namespace Boxfriend.Utils
+{
+	public abstract class SingletonBehaviour<T> : MonoBehaviour where T : SingletonBehaviour<T>
+	{
+		private static T _instance;
+		[SerializeField] protected bool _dontDestroy;
+
+		public static T Instance
+		{
+			get
+			{
+				if( _instance == null )
+				{
+					var go = new GameObject(typeof(T).Name);
+					go.AddComponent<T>();
+				}
+
+				return _instance;
+			}
+
+			private set
+			{
+				if (_instance == null)
+					_instance = value;
+				else if (value != _instance)
+					Destroy(value.gameObject);
+			}
+		}
+
+		protected virtual void __internalAwake ()
+		{
+			Instance = (T)this;
+            
+			if(_dontDestroy)
+				DontDestroyOnLoad(gameObject);
+		}
+	}
+}