WIP: UI system, containers and widgets.

Voile/Source/UI/IElement.cs

@@ -0,0 +1,28 @@
+using System.Numerics;
+using Voile.Input;
+using Voile.Rendering;
+
+namespace Voile.UI;
+
+public interface IElement
+{
+    public Vector2 Position { get; set; }
+}
+
+public interface IParentableElement
+{
+    public IReadOnlyList<IElement> Children { get; }
+    public void AddChild(IElement child);
+}
+
+public interface IRenderableElement
+{
+    public bool Visible { get; set; }
+    public void Render(RenderSystem renderer, Style style);
+}
+
+public interface IInputElement
+{
+    public bool IgnoreInput { get; set; }
+    void Input(IInputAction action);
+}