From 4856800f5f06616770c04953ed143147d57372fa Mon Sep 17 00:00:00 2001
From: Syntriax <syntriax@gmail.com>
Date: Sun, 3 Nov 2024 20:13:25 +0300
Subject: [PATCH] feat: Improved Entering & Exiting of Hierarchy Objects

---
 .../Abstract/Assignable/IHierarchyObject.cs        | 10 ++++++----
 Engine.Core/Behaviour.cs                           | 14 +++++++++-----
 Engine.Core/GameManager.cs                         |  2 +-
 Engine.Core/GameObject.cs                          |  6 +++---
 Engine.Core/HierarchyObjectBase.cs                 | 10 ++++------
 5 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/Engine.Core/Abstract/Assignable/IHierarchyObject.cs b/Engine.Core/Abstract/Assignable/IHierarchyObject.cs
index 61fe5b3..be67532 100644
--- a/Engine.Core/Abstract/Assignable/IHierarchyObject.cs
+++ b/Engine.Core/Abstract/Assignable/IHierarchyObject.cs
@@ -49,14 +49,16 @@ public interface IHierarchyObject : IEntity, INameable
     internal bool ExitHierarchy();
 
     /// <summary>
-    /// Delegate type for the event triggered when the <see cref="IEntity"/> enters the hierarchy.
+    /// Delegate type for the event triggered when the <see cref="IEntity"/> enters the hierarchy of a <see cref="IGameManager">.
     /// </summary>
     /// <param name="sender">The <see cref="IEntity"/> that entered the hierarchy.</param>
-    delegate void OnEnteredHierarchyDelegate(IHierarchyObject sender);
+    /// <param name="gameManager">The <see cref="IGameManager"/> that the <see cref="IEntity"/> has entered it's hierarchy.</param>
+    delegate void OnEnteredHierarchyDelegate(IHierarchyObject sender, IGameManager gameManager);
 
     /// <summary>
-    /// Delegate type for the event triggered when the <see cref="IEntity"/> exits the hierarchy.
+    /// Delegate type for the event triggered when the <see cref="IEntity"/> exits the hierarchy of a <see cref="IGameManager">.
     /// </summary>
     /// <param name="sender">The <see cref="IEntity"/> that exited the hierarchy.</param>
-    delegate void OnExitedHierarchyDelegate(IHierarchyObject sender);
+    /// <param name="gameManager">The <see cref="IGameManager"/> that the <see cref="IEntity"/> has exited it's hierarchy.</param>
+    delegate void OnExitedHierarchyDelegate(IHierarchyObject sender, IGameManager gameManager);
 }
diff --git a/Engine.Core/Behaviour.cs b/Engine.Core/Behaviour.cs
index 4b20863..a16cea0 100644
--- a/Engine.Core/Behaviour.cs
+++ b/Engine.Core/Behaviour.cs
@@ -33,7 +33,7 @@ public abstract class Behaviour : BehaviourBase
         OnInitialize();
 
         if (GameObject.IsInHierarchy)
-            EnteredHierarchy(GameObject);
+            EnteredHierarchy(GameObject, GameObject.GameManager ?? throw new System.Exception("Unexpected Error"));
     }
 
     protected virtual void OnFinalize() { }
@@ -44,7 +44,11 @@ public abstract class Behaviour : BehaviourBase
         BehaviourController.OnUpdate -= Update;
         BehaviourController.GameObject.OnEnteredHierarchy -= EnteredHierarchy;
         BehaviourController.GameObject.OnExitedHierarchy -= ExitedHierarchy;
+
         OnFinalize();
+
+        if (GameObject.IsInHierarchy)
+            ExitedHierarchy(GameObject, GameObject.GameManager ?? throw new System.Exception("Unexpected Error"));
     }
 
     protected virtual void OnPreUpdatePreActiveCheck() { }
@@ -93,9 +97,9 @@ public abstract class Behaviour : BehaviourBase
         OnPreDraw();
     }
 
-    protected virtual void OnEnteredHierarchy() { }
-    private void EnteredHierarchy(IHierarchyObject sender) => OnEnteredHierarchy();
+    protected virtual void OnEnteredHierarchy(IGameManager gameManager) { }
+    private void EnteredHierarchy(IHierarchyObject sender, IGameManager gameManager) => OnEnteredHierarchy(gameManager);
 
-    protected virtual void OnExitedHierarchy() { }
-    private void ExitedHierarchy(IHierarchyObject sender) => OnExitedHierarchy();
+    protected virtual void OnExitedHierarchy(IGameManager gameManager) { }
+    private void ExitedHierarchy(IHierarchyObject sender, IGameManager gameManager) => OnExitedHierarchy(gameManager);
 }
diff --git a/Engine.Core/GameManager.cs b/Engine.Core/GameManager.cs
index 73e25a7..af7c6bd 100644
--- a/Engine.Core/GameManager.cs
+++ b/Engine.Core/GameManager.cs
@@ -180,7 +180,7 @@ public class GameManager : BaseEntity, IGameManager
             Unregister(gameObject);
     }
 
-    private void OnGameObjectExitedHierarchy(IHierarchyObject sender)
+    private void OnGameObjectExitedHierarchy(IHierarchyObject sender, IGameManager gameManager)
     {
         if (sender is IGameObject gameObject)
             Unregister(gameObject);
diff --git a/Engine.Core/GameObject.cs b/Engine.Core/GameObject.cs
index a82e692..794db4d 100644
--- a/Engine.Core/GameObject.cs
+++ b/Engine.Core/GameObject.cs
@@ -109,17 +109,17 @@ public class GameObject : BaseEntity, IGameObject
             return false;
 
         _gameManager = gameManager;
-        OnEnteredHierarchy?.Invoke(this);
+        OnEnteredHierarchy?.Invoke(this, gameManager);
         return true;
     }
 
     bool IHierarchyObject.ExitHierarchy()
     {
-        if (!IsInHierarchy)
+        if (!IsInHierarchy || _gameManager is not IGameManager gameManager)
             return false;
 
         _gameManager = null;
-        OnExitedHierarchy?.Invoke(this);
+        OnExitedHierarchy?.Invoke(this, gameManager);
         return true;
     }
 }
diff --git a/Engine.Core/HierarchyObjectBase.cs b/Engine.Core/HierarchyObjectBase.cs
index ea855f2..9400f43 100644
--- a/Engine.Core/HierarchyObjectBase.cs
+++ b/Engine.Core/HierarchyObjectBase.cs
@@ -124,21 +124,19 @@ public abstract class HierarchyObjectBase : IHierarchyObject
 
         _gameManager = gameManager;
         OnEnteringHierarchy(gameManager);
-        OnEnteredHierarchy?.Invoke(this);
+        OnEnteredHierarchy?.Invoke(this, gameManager);
         return true;
     }
 
     protected virtual void OnExitingHierarchy(IGameManager gameManager) { }
     bool IHierarchyObject.ExitHierarchy()
     {
-        if (!IsInHierarchy)
+        if (!IsInHierarchy || _gameManager is not IGameManager gameManager)
             return false;
 
-        IGameManager? previousGameManager = _gameManager;
         _gameManager = null;
-        if (previousGameManager is not null)
-            OnExitingHierarchy(previousGameManager);
-        OnExitedHierarchy?.Invoke(this);
+        OnExitingHierarchy(gameManager);
+        OnExitedHierarchy?.Invoke(this, gameManager);
         return true;
     }
 }