Nullability for text related types

src/Avalonia.Visuals/ApiCompatBaseline.txt

@@ -5,6 +5,8 @@ InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Task
 MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean, System.Threading.CancellationToken)' is present in the implementation but not in the contract.
 MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.PageSlide.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Media.GlyphRun..ctor()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Media.GlyphRun.GlyphTypeface.set(Avalonia.Media.GlyphTypeface)' does not exist in the implementation but it does exist in the contract.
 TypeCannotChangeClassification : Type 'Avalonia.Media.Immutable.ImmutableSolidColorBrush' is a 'class' in the implementation but is a 'struct' in the contract.
 MembersMustExist : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext)' does not exist in the implementation but it does exist in the contract.
 CannotAddAbstractMembers : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext, Avalonia.Point)' is abstract in the implementation but is missing in the contract.
@@ -77,4 +79,4 @@ InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWr
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmap(System.String)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToHeight(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToWidth(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
-Total Issues: 78
+Total Issues: 79

src/Avalonia.Visuals/Media/FontFallback.cs

@@ -8,7 +8,7 @@
         /// <summary>
         /// Get or set the fallback <see cref="FontFamily"/>
         /// </summary>
-        public FontFamily FontFamily { get; set; }
+        public FontFamily FontFamily { get; set; } = FontFamily.Default;
 
         /// <summary>
         /// Get or set the <see cref="UnicodeRange"/> that is covered by the fallback.

src/Avalonia.Visuals/Media/FontManager.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Media
         private readonly ConcurrentDictionary<Typeface, GlyphTypeface> _glyphTypefaceCache =
             new ConcurrentDictionary<Typeface, GlyphTypeface>();
         private readonly FontFamily _defaultFontFamily;
-        private readonly IReadOnlyList<FontFallback> _fontFallbacks;
+        private readonly IReadOnlyList<FontFallback>? _fontFallbacks;
 
         public FontManager(IFontManagerImpl platformImpl)
         {
@@ -87,7 +87,7 @@ namespace Avalonia.Media
         /// <returns>
         ///     The <see cref="GlyphTypeface"/>.
         /// </returns>
-        public GlyphTypeface? GetOrAddGlyphTypeface(Typeface typeface)
+        public GlyphTypeface GetOrAddGlyphTypeface(Typeface typeface)
         {
             while (true)
             {
@@ -105,7 +105,7 @@ namespace Avalonia.Media
 
                 if (typeface.FontFamily == _defaultFontFamily)
                 {
-                    return null;
+                   throw new InvalidOperationException($"Could not create glyph typeface for: {typeface.FontFamily.Name}.");
                 }
 
                 typeface = new Typeface(_defaultFontFamily, typeface.Style, typeface.Weight);
@@ -126,7 +126,7 @@ namespace Avalonia.Media
         /// </returns>
         public bool TryMatchCharacter(int codepoint, FontStyle fontStyle,
             FontWeight fontWeight,
-            FontFamily fontFamily, CultureInfo culture, out Typeface typeface)
+            FontFamily? fontFamily, CultureInfo? culture, out Typeface typeface)
         {
             if(_fontFallbacks != null)
             {

src/Avalonia.Visuals/Media/FontManagerOptions.cs

@@ -4,8 +4,8 @@ namespace Avalonia.Media
 {
     public class FontManagerOptions
     {
-        public string DefaultFamilyName { get; set; }
+        public string? DefaultFamilyName { get; set; }
 
-        public IReadOnlyList<FontFallback> FontFallbacks { get; set; }
+        public IReadOnlyList<FontFallback>? FontFallbacks { get; set; }
     }
 }

src/Avalonia.Visuals/Media/Fonts/FontFamilyLoader.cs

@@ -89,7 +89,7 @@ namespace Avalonia.Media.Fonts
             {
                 fileExtension = "." + fontFamilyKey.Source.AbsolutePath.Split('.').LastOrDefault();
 
-                var fileName = fontFamilyKey.Source.LocalPath.Replace(fileExtension, string.Empty).Split('.').LastOrDefault();
+                var fileName = fontFamilyKey.Source.LocalPath.Replace(fileExtension, string.Empty).Split('.').Last();
 
                 location = new Uri(fontFamilyKey.Source.AbsoluteUri.Replace("." + fileName + fileExtension, string.Empty), UriKind.RelativeOrAbsolute);
 

src/Avalonia.Visuals/Media/GlyphRun.cs

@@ -27,14 +27,6 @@ namespace Avalonia.Media
         private ReadOnlySlice<ushort> _glyphClusters;
         private ReadOnlySlice<char> _characters;
 
-        /// <summary>
-        ///     Initializes a new instance of the <see cref="GlyphRun"/> class.
-        /// </summary>
-        public GlyphRun()
-        {
-
-        }
-
         /// <summary>
         ///     Initializes a new instance of the <see cref="GlyphRun"/> class by specifying properties of the class.
         /// </summary>
@@ -56,7 +48,7 @@ namespace Avalonia.Media
             ReadOnlySlice<ushort> glyphClusters = default,
             int biDiLevel = 0)
         {
-            GlyphTypeface = glyphTypeface;
+            _glyphTypeface = glyphTypeface;
 
             FontRenderingEmSize = fontRenderingEmSize;
 
@@ -74,13 +66,9 @@ namespace Avalonia.Media
         }
 
         /// <summary>
-        ///     Gets or sets the <see cref="Media.GlyphTypeface"/> for the <see cref="GlyphRun"/>.
+        ///     Gets the <see cref="Media.GlyphTypeface"/> for the <see cref="GlyphRun"/>.
         /// </summary>
-        public GlyphTypeface GlyphTypeface
-        {
-            get => _glyphTypeface;
-            set => Set(ref _glyphTypeface, value);
-        }
+        public GlyphTypeface GlyphTypeface => _glyphTypeface;
 
         /// <summary>
         ///     Gets or sets the em size used for rendering the <see cref="GlyphRun"/>.

src/Avalonia.Visuals/Media/GlyphTypeface.cs

@@ -8,8 +8,8 @@ namespace Avalonia.Media
         public const int InvisibleGlyph = 3;
 
         public GlyphTypeface(Typeface typeface) 
-            : this(FontManager.Current?.PlatformImpl.CreateGlyphTypeface(typeface))
-        { 
+            : this(FontManager.Current.PlatformImpl.CreateGlyphTypeface(typeface)) 
+        {
         }
 
         public GlyphTypeface(IGlyphTypefaceImpl platformImpl)

src/Avalonia.Visuals/Media/TextFormatting/TextFormatterImpl.cs

@@ -277,7 +277,7 @@ namespace Avalonia.Media.TextFormatting
 
             var textRuns = new List<ShapedTextCharacters>();
 
-            if (previousLineBreak != null)
+            if (previousLineBreak?.RemainingCharacters != null)
             {
                 for (var index = 0; index < previousLineBreak.RemainingCharacters.Count; index++)
                 {
@@ -317,7 +317,7 @@ namespace Avalonia.Media.TextFormatting
 
             while (textRunEnumerator.MoveNext())
             {
-                var textRun = textRunEnumerator.Current;
+                var textRun = textRunEnumerator.Current!;
 
                 switch (textRun)
                 {
@@ -398,7 +398,7 @@ namespace Avalonia.Media.TextFormatting
         /// <param name="currentLineBreak">The current line break if the line was explicitly broken.</param>
         /// <returns>The wrapped text line.</returns>
         private static TextLine PerformTextWrapping(List<ShapedTextCharacters> textRuns, TextRange textRange,
-            double paragraphWidth, TextParagraphProperties paragraphProperties, TextLineBreak currentLineBreak)
+            double paragraphWidth, TextParagraphProperties paragraphProperties, TextLineBreak? currentLineBreak)
         {
             var availableWidth = paragraphWidth;
             var currentWidth = 0.0;
@@ -517,7 +517,7 @@ namespace Avalonia.Media.TextFormatting
 
             var lineBreak = remainingCharacters?.Count > 0 ? new TextLineBreak(remainingCharacters) : null;
 
-            if (lineBreak is null && currentLineBreak.TextEndOfLine != null)
+            if (lineBreak is null && currentLineBreak?.TextEndOfLine != null)
             {
                 lineBreak = new TextLineBreak(currentLineBreak.TextEndOfLine);
             }
@@ -586,11 +586,11 @@ namespace Avalonia.Media.TextFormatting
             {
                 _textSource = textSource;
                 _pos = firstTextSourceIndex;
-                Current = null!;
+                Current = null;
             }
 
             // ReSharper disable once MemberHidesStaticFromOuterClass
-            public TextRun Current { get; private set; }
+            public TextRun? Current { get; private set; }
 
             public bool MoveNext()
             {

src/Avalonia.Visuals/Media/TextFormatting/TextLineImpl.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using Avalonia.Media.TextFormatting.Unicode;
 using Avalonia.Platform;
 using Avalonia.Utilities;
@@ -479,12 +480,13 @@ namespace Avalonia.Media.TextFormatting
         /// </returns>
         internal static ShapedTextCharacters CreateShapedSymbol(TextRun textRun)
         {
-            var formatterImpl = AvaloniaLocator.Current.GetService<ITextShaperImpl>();
+            var properties = textRun.Properties;
 
-            var glyphRun = formatterImpl.ShapeText(textRun.Text, textRun.Properties.Typeface, textRun.Properties.FontRenderingEmSize,
-                textRun.Properties.CultureInfo);
+            _ = properties ?? throw new InvalidOperationException($"{nameof(TextRun.Properties)} should not be null.");
 
-            return new ShapedTextCharacters(glyphRun, textRun.Properties);
+            var glyphRun = TextShaper.Current.ShapeText(textRun.Text, properties.Typeface, properties.FontRenderingEmSize, properties.CultureInfo);
+
+            return new ShapedTextCharacters(glyphRun, properties);
         }
     }
 }

src/Avalonia.Visuals/Media/Typeface.cs

@@ -66,7 +66,7 @@ namespace Avalonia.Media
         /// <value>
         /// The glyph typeface.
         /// </value>
-        public GlyphTypeface? GlyphTypeface => FontManager.Current.GetOrAddGlyphTypeface(this);
+        public GlyphTypeface GlyphTypeface => FontManager.Current.GetOrAddGlyphTypeface(this);
 
         public static bool operator !=(Typeface a, Typeface b)
         {

src/Avalonia.Visuals/Media/UnicodeRange.cs

@@ -37,7 +37,7 @@ namespace Avalonia.Media
 
         internal UnicodeRangeSegment Single => _single;
 
-        internal IReadOnlyList<UnicodeRangeSegment> Segments => _segments;
+        internal IReadOnlyList<UnicodeRangeSegment>? Segments => _segments;
 
         /// <summary>
         /// Determines if given value is inside the range.