rendering-mewui-elementslisted

## Rendering Pipeline MewUI uses a three-pass layout system: ``` Measure (calculate DesiredSize) → Arrange (set Bounds) → Render (draw via IGraphicsContext) ``` **Key overrides in custom controls:** - `MeasureContent(Size availableSize)` → return desired size - `ArrangeContent(Rect bounds)` → position children - `OnRender(IGraphicsContext context)` → draw visuals --- ## IGraphicsContext Essentials ```csharp protected override void OnRender(IGraphicsContext context) { var bounds = new Rect(0, 0, Bounds.Width, Bounds.Height); // State management (always Save/Restore) context.Save(); context.Translate(10, 10); context.SetClip(clipRect); // ... drawing ... context.Restore(); // Drawing primitives context.FillRectangle(bounds, Colors.Blue); context.DrawRectangle(bounds, Colors.Black, thickness: 1); context.FillRoundedRectangle(bounds, radiusX: 4, radiusY: 4, Colors.White); context.DrawLine(start, end, Colors.Gray, thickness: 1); context.FillEllipse(bounds, Colors.Red); // Text - note parameter order: text, bounds, font, color, alignments, wrapping context.DrawText("Hello", bounds, font, Colors.Black, TextAlignment.Center, TextAlignment.Center, TextWrapping.NoWrap); // Images context.DrawImage(image, destRect); } ``` --- ## Text Measurement ```csharp protected override Size MeasureContent(Size availableSize) { var factory = GetGraphicsFactory(); using var ctx = factory.CreateMeasurement