Engine.Core/Abstract/IUniverseObject.cs

@@ -47,7 +47,7 @@ public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourCon
     /// <summary>
     /// The parent <see cref="IUniverseObject"/> of the <see cref="IUniverseObject"/>.
     /// </summary>
-    IUniverseObject? Parent { get; }
+    IUniverseObject? Parent { get; set; }
 
     /// <summary>
     /// The <see cref="IUniverseObject"/>s that have this <see cref="IUniverseObject"/> as their <see cref="Parent"/>.
@@ -75,12 +75,6 @@ public interface IUniverseObject : IEntity, IActive, INameable, IHasBehaviourCon
     /// </returns>
     internal bool ExitUniverse();
 
-    /// <summary>
-    /// Sets the parent <see cref="IUniverseObject"/> of this <see cref="IUniverseObject"/>.
-    /// </summary>
-    /// <param name="universeObject">The parent <see cref="IUniverseObject"/> to set.</param>
-    void SetParent(IUniverseObject? universeObject);
-
     /// <summary>
     /// Adds a child <see cref="IUniverseObject"/> to this <see cref="IUniverseObject"/>.
     /// </summary>

Engine.Core/Extensions/UniverseObjectExtensions.cs

@@ -12,7 +12,7 @@ public static class UniverseObjectExtensions
         if (!string.IsNullOrWhiteSpace(name))
             universeObject.Name = name;
         if (parent is not null)
-            universeObject.SetParent(parent);
+            universeObject.Parent = parent;
         return universeObject;
     }
 

Engine.Core/Universe.cs

@@ -83,7 +83,7 @@ public class Universe : BaseEntity, IUniverse
 
     public void Remove(IUniverseObject universeObject)
     {
-        universeObject.SetParent(null);
+        universeObject.Parent = null;
         RemoveIncursive(universeObject);
     }
 

Engine.Core/UniverseObject.cs

@@ -1,4 +1,3 @@
-using System.Collections;
 using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
@@ -21,8 +20,8 @@ public class UniverseObject : BaseEntity, IUniverseObject
     private IBehaviourController _behaviourController = null!;
     private bool _isActive = false;
     private readonly List<IUniverseObject> _children = [];
+    private IUniverseObject? _parent = null;
 
-    public IUniverseObject? Parent { get; private set; } = null;
     public IReadOnlyList<IUniverseObject> Children => _children;
     public IBehaviourController BehaviourController => _behaviourController;
     public IUniverse Universe => _universe;
@@ -42,6 +41,40 @@ public class UniverseObject : BaseEntity, IUniverseObject
         }
     }
 
+    public IUniverseObject? Parent
+    {
+        get => _parent;
+        set
+        {
+            if (value == this)
+                throw new Exceptions.AssignFailedException($"{Name} can not parent itself");
+
+            if (_parent == value)
+                return;
+
+            IUniverseObject? previousParent = Parent;
+            if (previousParent is not null)
+            {
+                previousParent.RemoveChild(this);
+                previousParent.OnActiveChanged.RemoveListener(OnParentActiveChanged);
+            }
+
+            _parent = value;
+
+            if (value is not null)
+            {
+                if (value.IsInUniverse && !IsInUniverse)
+                    value.Universe.Register(this);
+
+                value.AddChild(this);
+                value.OnActiveChanged.AddListener(OnParentActiveChanged);
+            }
+
+            UpdateActive();
+            OnParentChanged?.Invoke(this, new(previousParent, value));
+        }
+    }
+
     protected virtual void OnEnteringUniverse(IUniverse universe) { }
     bool IUniverseObject.EnterUniverse(IUniverse universe)
     {
@@ -67,43 +100,13 @@ public class UniverseObject : BaseEntity, IUniverseObject
         return true;
     }
 
-    public void SetParent(IUniverseObject? parent)
-    {
-        if (parent == this)
-            throw new Exceptions.AssignFailedException($"{Name} can not parent itself");
-
-        if (Parent == parent)
-            return;
-
-        IUniverseObject? previousParent = Parent;
-        if (previousParent is not null)
-        {
-            previousParent.RemoveChild(this);
-            previousParent.OnActiveChanged.RemoveListener(OnParentActiveChanged);
-        }
-
-        Parent = parent;
-
-        if (parent is not null)
-        {
-            if (parent.IsInUniverse && !IsInUniverse)
-                parent.Universe.Register(this);
-
-            parent.AddChild(this);
-            parent.OnActiveChanged.AddListener(OnParentActiveChanged);
-        }
-
-        UpdateActive();
-        OnParentChanged?.Invoke(this, new(previousParent, parent));
-    }
-
     public void AddChild(IUniverseObject parent)
     {
         if (_children.Contains(parent))
             return;
 
         _children.Add(parent);
-        parent.SetParent(this);
+        parent.Parent = this;
         OnChildrenAdded?.Invoke(this, new(parent));
     }
 
@@ -112,7 +115,7 @@ public class UniverseObject : BaseEntity, IUniverseObject
         if (!_children.Remove(child))
             return;
 
-        child.SetParent(null);
+        child.Parent = null;
         OnChildrenRemoved?.Invoke(this, new(child));
     }