WIP: UI system, containers and widgets.

Voile/Source/UI/Widgets/Widget.cs

@@ -0,0 +1,41 @@
+using System.Numerics;
+using Voile.Input;
+using Voile.Rendering;
+
+namespace Voile.UI.Widgets;
+
+/// <summary>
+/// A base class for all UI widgets.
+/// </summary>
+public abstract class Widget : IElement, IRenderableElement, IInputElement
+{
+    public bool Visible { get; set; } = true;
+    public bool IgnoreInput { get; set; }
+    public Vector2 Position { get; set; } = Vector2.Zero;
+
+    public Widget()
+    {
+
+    }
+
+    public Widget(Vector2 position)
+    {
+        Position = position;
+    }
+
+    /// <summary>
+    /// Get a minimum rectangle size for this widget.
+    /// </summary>
+    public abstract Rect MinimumRect { get; }
+
+    /// <summary>
+    /// Called when its time to draw this widget.
+    /// </summary>
+    /// <param name="renderer"></param>
+    public abstract void Render(RenderSystem renderer, Style style);
+    /// <summary>
+    /// Called when this widget receives input.
+    /// </summary>
+    /// <param name="action">An input action this widget received.</param>
+    public abstract void Input(IInputAction action);
+}