WIP: dirty flag for UI.

Voile/Source/UI/IElement.cs

@@ -6,14 +6,31 @@ namespace Voile.UI;
 
 public interface IElement
 {
+    /// <summary>
+    /// This element's position in pixels relative to the viewport top-left edge.
+    /// </summary>
     public Vector2 Position { get; set; }
+    /// <summary>
+    /// The size of this element.
+    /// </summary>
     public Rect Size { get; set; }
 }
 
 public interface IParentableElement
 {
+    /// <summary>
+    /// This parentable element's children.
+    /// </summary>
     public IReadOnlyList<IElement> Children { get; }
+    /// <summary>
+    /// Add a child element to this element.
+    /// </summary>
+    /// <param name="child">Child <see cref="IElement"/>.</param>
     public void AddChild(IElement child);
+    /// <summary>
+    /// Remove a child element from this element.
+    /// </summary>
+    /// <param name="child">Child <see cref="IElement"/> to remove.</param>
     public void RemoveChild(IElement child);
 }
 
@@ -27,18 +44,48 @@ public interface IResizeableElement
 
 public interface IUpdatableElement
 {
+    /// <summary>
+    /// Specifies if this element's properties have changed, making it necessary to update it.
+    /// </summary>
+    public bool Dirty { get; }
+    /// <summary>
+    /// Update this element.
+    /// </summary>
     void Update();
+    /// <summary>
+    /// Marks this element as changed, requiring an update.
+    /// </summary>
+    void MarkDirty();
 }
 
 public interface IRenderableElement
 {
+    /// <summary>
+    /// Specifies if this element should be drawn.
+    /// </summary>
     public bool Visible { get; set; }
+    /// <summary>
+    /// Render this element.
+    /// </summary>
+    /// <param name="renderer">Renderer to call draw operations on.</param>
+    /// <param name="style">A style to use to draw this element.</param>
     public void Render(RenderSystem renderer, Style style);
+    /// <summary>
+    /// Draws this element's size bounds.
+    /// </summary>
+    /// <param name="renderer">Renderer to use.</param>
     public void DrawSize(RenderSystem renderer);
 }
 
 public interface IInputElement
 {
+    /// <summary>
+    /// Specifies if this element should ignore inputs.
+    /// </summary>
     public bool IgnoreInput { get; set; }
+    /// <summary>
+    /// Send an input action to this element.
+    /// </summary>
+    /// <param name="action">Input action to send.</param>
     void Input(IInputAction action);
 }