Add MarginContainer, mark parent elements dirty when child gets marked dirty too.

TestGame/TestGame.cs

@@ -56,7 +56,8 @@ public class TestGame : Game
         Input.AddInputMapping("reload", new IInputAction[] { new KeyInputAction(KeyboardKey.R) });
         _emitterId = _particleSystem.CreateEmitter(Renderer.WindowSize / 2, _fireEffect);
 
-        _fillContainer.AddChild(_container);
+        _fillContainer.AddChild(_marginContainer);
+        _marginContainer.AddChild(_container);
 
         _uiSystem.AddElement(_fillContainer);
     }
@@ -129,21 +130,20 @@ public class TestGame : Game
 
     private FlexContainer _container = new(minimumSize: new Rect(64.0f, 64.0f), new())
     {
-        ConfineToContents = true,
         Anchor = Anchor.Center,
-        Size = new Rect(500, 300),
         Direction = FlexDirection.Column,
         Justify = JustifyContent.Start,
         Align = AlignItems.Center,
         Wrap = true,
-        Gap = 10f
+        Gap = 8.0f
     };
 
     private FillContainer _fillContainer = new();
+    private MarginContainer _marginContainer = new(new Margin(32.0f))
+    {
+    };
     // private HorizontalContainer _container = new(new Rect(128.0f, 64.0f), new(), 16)
     // {
     //     ConfineToContents = true,
-    //     Anchor = Anchor.CenterRight,
-    //     AnchorOffset = new Vector2(0.5f, 0.0f)
     // };
 }