feat(skiawpf): Added support for FontWeight, FontStyle & FontStretch.…

… Works only with Font Families, not when specifying font file directly.

src/Uno.UI/UI/Xaml/Controls/TextBlock/TextVisual.Skia.cs

@@ -6,19 +6,26 @@
 using Uno.UI.Xaml;
 using Windows.Foundation;
 using Windows.Storage;
+using Windows.UI.Text;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Media;
 
 namespace Windows.UI.Composition
 {
 	internal class TextVisual : Visual
 	{
-		private SKPaint _paint;
-		private static Func<string, SKTypeface> _getTypeFace = Funcs.CreateMemoized<string, SKTypeface>(FromFamilyName);
+		private readonly SKPaint _paint;
+		private static readonly Func<string, SKFontStyleWeight, SKFontStyleWidth, SKFontStyleSlant, SKTypeface> _getTypeFace =
+			Funcs.CreateMemoized<string, SKFontStyleWeight, SKFontStyleWidth, SKFontStyleSlant, SKTypeface>(
+				(nm, wt, wh, sl) => FromFamilyName(nm, wt, wh, sl));
 
 		private readonly TextBlock _owner;
 
-		private static SKTypeface FromFamilyName(string name)
+		private static SKTypeface FromFamilyName(
+			string name,
+			SKFontStyleWeight weight,
+			SKFontStyleWidth width,
+			SKFontStyleSlant slant)
 		{
 			if (name.StartsWith(XamlFilePathHelper.AppXIdentifier))
 			{
@@ -32,27 +39,34 @@ private static SKTypeface FromFamilyName(string name)
 			}
 			else
 			{
-				return SKTypeface.FromFamilyName(name);
+				return SKTypeface.FromFamilyName(name, weight, width, slant);
 			}
 		}
 
 		public TextVisual(Compositor compositor, TextBlock owner) : base(compositor)
 		{
 			_owner = owner;
 
-			_paint = new SKPaint();
-			_paint.TextEncoding = SKTextEncoding.Utf16;
-			_paint.IsStroke = false;
-			_paint.IsAntialias = true;
-			_paint.LcdRenderText = true;
-			_paint.SubpixelText = true;
+			_paint = new SKPaint
+			{
+				TextEncoding = SKTextEncoding.Utf16,
+				IsStroke = false,
+				IsAntialias = true,
+				LcdRenderText = true,
+				SubpixelText = true
+			};
 		}
 
 		internal Size Measure(Size availableSize)
 		{
 			if (_owner.FontFamily?.Source != null)
 			{
-				_paint.Typeface = _getTypeFace(_owner.FontFamily.Source);
+				var weight = _owner.FontWeight.ToSkiaWeight();
+				//var width = _owner.FontStretch.ToSkiaWidth(); -- FontStretch not supported by Uno yet
+				var width = SKFontStyleWidth.Normal;
+				var slant = _owner.FontStyle.ToSkiaSlant();
+				var font = _getTypeFace(_owner.FontFamily.Source, weight, width, slant);
+				_paint.Typeface = font;
 			}
 
 			_paint.TextSize = (float)_owner.FontSize;

src/Uno.UWP/UI/Text/FontStyle.skia.cs

@@ -0,0 +1,16 @@
+using SkiaSharp;
+
+namespace Windows.UI.Text
+{
+	internal static class FontStyleExtensions
+	{
+		public static SKFontStyleSlant ToSkiaSlant(this FontStyle style) =>
+			style switch
+			{
+				FontStyle.Italic => SKFontStyleSlant.Italic,
+				FontStyle.Normal => SKFontStyleSlant.Upright,
+				FontStyle.Oblique => SKFontStyleSlant.Oblique,
+				_ => SKFontStyleSlant.Upright
+			};
+	}
+}

src/Uno.UWP/UI/Text/FontWeight.skia.cs

@@ -0,0 +1,15 @@
+using SkiaSharp;
+
+namespace Windows.UI.Text
+{
+	partial struct FontWeight
+	{
+		public SKFontStyleWeight ToSkiaWeight()
+		{
+			// Uno weight values are using the same system,
+			// so we can convert directly to Skia system
+			// without need for a mapping.
+			return (SKFontStyleWeight)this.Weight;
+		}
+	}
+}