Merge branch 'master' into consistent-LangVersion

3 years ago · 629b1cad1b
71 changed files with 173 additions and 213 deletions
--- a/samples/ControlCatalog.Desktop/Program.cs
+++ b/samples/ControlCatalog.Desktop/Program.cs
@ -23,7 +23,7 @@ namespace ControlCatalog
        private static void ConfigureAssetAssembly(AppBuilder builder)
        {
            AvaloniaLocator.CurrentMutable
-                .GetService<IAssetLoader>()
+                .GetRequiredService<IAssetLoader>()
                .SetDefaultAssembly(typeof(App).Assembly);
        }
    }
--- a/samples/ControlCatalog/Pages/TabControlPage.xaml.cs
+++ b/samples/ControlCatalog/Pages/TabControlPage.xaml.cs
@ -51,7 +51,7 @@ namespace ControlCatalog.Pages

        private static IBitmap LoadBitmap(string uri)
        {
-            var assets = AvaloniaLocator.Current!.GetService<IAssetLoader>()!;
+            var assets = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
            return new Bitmap(assets.Open(new Uri(uri)));
        }
    }
--- a/samples/ControlCatalog/Pages/TextBoxPage.xaml
+++ b/samples/ControlCatalog/Pages/TextBoxPage.xaml
@ -38,7 +38,7 @@
                 UseFloatingWatermark="True"
                 PasswordChar="*"
                 Text="Password" />
-        <TextBox Width="200" Text="Left aligned text" TextAlignment="Left" />
+        <TextBox Width="200" Text="Left aligned text" TextAlignment="Left" AcceptsTab="True" />
        <TextBox Width="200" Text="Center aligned text" TextAlignment="Center" />
        <TextBox Width="200" Text="Right aligned text" TextAlignment="Right" />
        <TextBox Width="200" Text="Custom selection brush"
--- a/samples/ControlCatalog/ViewModels/CursorPageViewModel.cs
+++ b/samples/ControlCatalog/ViewModels/CursorPageViewModel.cs
@ -18,7 +18,7 @@ namespace ControlCatalog.ViewModels
                .Select(x => new StandardCursorModel(x))
                .ToList();

-            var loader = AvaloniaLocator.Current!.GetService<IAssetLoader>()!;
+            var loader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
            var s = loader.Open(new Uri("avares://ControlCatalog/Assets/avalonia-32.png"));
            var bitmap = new Bitmap(s);
            CustomCursor = new Cursor(bitmap, new PixelPoint(16, 16));
--- a/samples/ControlCatalog/ViewModels/TransitioningContentControlPageViewModel.cs
+++ b/samples/ControlCatalog/ViewModels/TransitioningContentControlPageViewModel.cs
@ -19,7 +19,7 @@ namespace ControlCatalog.ViewModels
    {
        public TransitioningContentControlPageViewModel()
        {
-            var assetLoader = AvaloniaLocator.Current?.GetService<IAssetLoader>()!;
+            var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();

            var images = new string[] 
            { 
--- a/src/Avalonia.Base/Data/Converters/FuncMultiValueConverter.cs
+++ b/src/Avalonia.Base/Data/Converters/FuncMultiValueConverter.cs
@ -38,7 +38,7 @@ namespace Avalonia.Data.Converters
                    }
                    else if (Equals(obj, default(TIn)))
                    {
-                        yield return default(TIn);
+                        yield return default;
                    }
                }
            }
--- a/src/Avalonia.Base/Input/Cursor.cs
+++ b/src/Avalonia.Base/Input/Cursor.cs
@ -71,8 +71,7 @@ namespace Avalonia.Input

        private static ICursorFactory GetCursorFactory()
        {
-            return AvaloniaLocator.Current.GetService<ICursorFactory>() ??
-                throw new Exception("Could not create Cursor: ICursorFactory not registered.");
+            return AvaloniaLocator.Current.GetRequiredService<ICursorFactory>();
        }
    }
 }
--- a/src/Avalonia.Base/Layout/WrapLayout/UvMeasure.cs
+++ b/src/Avalonia.Base/Layout/WrapLayout/UvMeasure.cs
@ -7,7 +7,7 @@ namespace Avalonia.Layout
 {    
    internal struct UvMeasure
    {
-        internal static readonly UvMeasure Zero = default(UvMeasure);
+        internal static readonly UvMeasure Zero = default;

        internal double U { get; set; }

--- a/src/Avalonia.Base/Media/DrawingContext.cs
+++ b/src/Avalonia.Base/Media/DrawingContext.cs
@ -279,7 +279,7 @@ namespace Avalonia.Media
                OpacityMask,
            }

-            public PushedState(DrawingContext context, PushedStateType type, Matrix matrix = default(Matrix))
+            public PushedState(DrawingContext context, PushedStateType type, Matrix matrix = default)
            {
                if (context._states is null)
                    throw new ObjectDisposedException(nameof(DrawingContext));
--- a/src/Avalonia.Base/Media/DrawingGroup.cs
+++ b/src/Avalonia.Base/Media/DrawingGroup.cs
@ -76,8 +76,8 @@ namespace Avalonia.Media
        {
            using (context.PushPreTransform(Transform?.Value ?? Matrix.Identity))
            using (context.PushOpacity(Opacity))
-            using (ClipGeometry != null ? context.PushGeometryClip(ClipGeometry) : default(DrawingContext.PushedState))
-            using (OpacityMask != null ? context.PushOpacityMask(OpacityMask, GetBounds()) : default(DrawingContext.PushedState))
+            using (ClipGeometry != null ? context.PushGeometryClip(ClipGeometry) : default)
+            using (OpacityMask != null ? context.PushOpacityMask(OpacityMask, GetBounds()) : default)
            {
                foreach (var drawing in Children)
                {
--- a/src/Avalonia.Base/Media/FontManager.cs
+++ b/src/Avalonia.Base/Media/FontManager.cs
@ -47,10 +47,7 @@ namespace Avalonia.Media
                    return current;
                }

-                var fontManagerImpl = AvaloniaLocator.Current.GetService<IFontManagerImpl>();
-
-                if (fontManagerImpl == null)
-                    throw new InvalidOperationException("No font manager implementation was registered.");
+                var fontManagerImpl = AvaloniaLocator.Current.GetRequiredService<IFontManagerImpl>();

                current = new FontManager(fontManagerImpl);

--- a/src/Avalonia.Base/Media/ImmediateDrawingContext.cs
+++ b/src/Avalonia.Base/Media/ImmediateDrawingContext.cs
@ -218,7 +218,7 @@ namespace Avalonia.Media
                OpacityMask,
            }

-            internal PushedState(ImmediateDrawingContext context, PushedStateType type, Matrix matrix = default(Matrix))
+            internal PushedState(ImmediateDrawingContext context, PushedStateType type, Matrix matrix = default)
            {
                if (context._states is null)
                    throw new ObjectDisposedException(nameof(ImmediateDrawingContext));
--- a/src/Avalonia.Base/Media/TextFormatting/InterWordJustification.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/InterWordJustification.cs
@ -91,7 +91,7 @@ namespace Avalonia.Media.TextFormatting
                    continue;
                }

-                if (textRun is ShapedTextCharacters shapedText)
+                if (textRun is ShapedTextRun shapedText)
                {
                    var glyphRun = shapedText.GlyphRun;
                    var shapedBuffer = shapedText.ShapedBuffer;
--- a/src/Avalonia.Base/Media/TextFormatting/ShapedTextCharacters.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/ShapedTextCharacters.cs
@ -6,11 +6,11 @@ namespace Avalonia.Media.TextFormatting
    /// <summary>
    /// A text run that holds shaped characters.
    /// </summary>
-    public sealed class ShapedTextCharacters : DrawableTextRun
+    public sealed class ShapedTextRun : DrawableTextRun
    {
        private GlyphRun? _glyphRun;

-        public ShapedTextCharacters(ShapedBuffer shapedBuffer, TextRunProperties properties)
+        public ShapedTextRun(ShapedBuffer shapedBuffer, TextRunProperties properties)
        {
            ShapedBuffer = shapedBuffer;
            CharacterBufferReference = shapedBuffer.CharacterBufferRange.CharacterBufferReference;
@ -155,7 +155,7 @@ namespace Avalonia.Media.TextFormatting
            return length > 0;
        }

-        internal SplitResult<ShapedTextCharacters> Split(int length)
+        internal SplitResult<ShapedTextRun> Split(int length)
        {
            if (IsReversed)
            {
@ -171,7 +171,7 @@ namespace Avalonia.Media.TextFormatting
            
            var splitBuffer = ShapedBuffer.Split(length);

-            var first = new ShapedTextCharacters(splitBuffer.First, Properties);
+            var first = new ShapedTextRun(splitBuffer.First, Properties);

            #if DEBUG

@ -182,9 +182,9 @@ namespace Avalonia.Media.TextFormatting

 #endif

-            var second = new ShapedTextCharacters(splitBuffer.Second!, Properties);
+            var second = new ShapedTextRun(splitBuffer.Second!, Properties);

-            return new SplitResult<ShapedTextCharacters>(first, second);
+            return new SplitResult<ShapedTextRun>(first, second);
        }

        internal GlyphRun CreateGlyphRun()
--- a/src/Avalonia.Base/Media/TextFormatting/TextCharacters.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextCharacters.cs
@ -91,12 +91,12 @@ namespace Avalonia.Media.TextFormatting
        public override TextRunProperties Properties { get; }

        /// <summary>
-        /// Gets a list of <see cref="ShapeableTextCharacters"/>.
+        /// Gets a list of <see cref="UnshapedTextRun"/>.
        /// </summary>
        /// <returns>The shapeable text characters.</returns>
-        internal IReadOnlyList<ShapeableTextCharacters> GetShapeableCharacters(CharacterBufferRange characterBufferRange, sbyte biDiLevel, ref TextRunProperties? previousProperties)
+        internal IReadOnlyList<UnshapedTextRun> GetShapeableCharacters(CharacterBufferRange characterBufferRange, sbyte biDiLevel, ref TextRunProperties? previousProperties)
        {
-            var shapeableCharacters = new List<ShapeableTextCharacters>(2);
+            var shapeableCharacters = new List<UnshapedTextRun>(2);

            while (characterBufferRange.Length > 0)
            {
@ -120,7 +120,7 @@ namespace Avalonia.Media.TextFormatting
        /// <param name="biDiLevel">The bidi level of the run.</param>
        /// <param name="previousProperties"></param>
        /// <returns>A list of shapeable text runs.</returns>
-        private static ShapeableTextCharacters CreateShapeableRun(CharacterBufferRange characterBufferRange,
+        private static UnshapedTextRun CreateShapeableRun(CharacterBufferRange characterBufferRange,
            TextRunProperties defaultProperties, sbyte biDiLevel, ref TextRunProperties? previousProperties)
        {
            var defaultTypeface = defaultProperties.Typeface;
@ -133,12 +133,12 @@ namespace Avalonia.Media.TextFormatting
                {
                    if (TryGetShapeableLength(characterBufferRange, previousTypeface.Value, null, out var fallbackCount, out _))
                    {
-                        return new ShapeableTextCharacters(characterBufferRange.CharacterBufferReference, fallbackCount,
+                        return new UnshapedTextRun(characterBufferRange.CharacterBufferReference, fallbackCount,
                            defaultProperties.WithTypeface(previousTypeface.Value), biDiLevel);
                    }
                }

-                return new ShapeableTextCharacters(characterBufferRange.CharacterBufferReference, count, defaultProperties.WithTypeface(currentTypeface),
+                return new UnshapedTextRun(characterBufferRange.CharacterBufferReference, count, defaultProperties.WithTypeface(currentTypeface),
                    biDiLevel);
            }

@ -146,7 +146,7 @@ namespace Avalonia.Media.TextFormatting
            {
                if (TryGetShapeableLength(characterBufferRange, previousTypeface.Value, defaultTypeface, out count, out _))
                {
-                    return new ShapeableTextCharacters(characterBufferRange.CharacterBufferReference, count,
+                    return new UnshapedTextRun(characterBufferRange.CharacterBufferReference, count,
                        defaultProperties.WithTypeface(previousTypeface.Value), biDiLevel);
                }
            }
@ -176,7 +176,7 @@ namespace Avalonia.Media.TextFormatting
            if (matchFound && TryGetShapeableLength(characterBufferRange, currentTypeface, defaultTypeface, out count, out _))
            {
                //Fallback found
-                return new ShapeableTextCharacters(characterBufferRange.CharacterBufferReference, count, defaultProperties.WithTypeface(currentTypeface),
+                return new UnshapedTextRun(characterBufferRange.CharacterBufferReference, count, defaultProperties.WithTypeface(currentTypeface),
                    biDiLevel);
            }

@ -199,7 +199,7 @@ namespace Avalonia.Media.TextFormatting
                count += grapheme.Text.Length;
            }

-            return new ShapeableTextCharacters(characterBufferRange.CharacterBufferReference, count, defaultProperties, biDiLevel);
+            return new UnshapedTextRun(characterBufferRange.CharacterBufferReference, count, defaultProperties, biDiLevel);
        }

        /// <summary>
--- a/src/Avalonia.Base/Media/TextFormatting/TextEllipsisHelper.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextEllipsisHelper.cs
@ -31,7 +31,7 @@ namespace Avalonia.Media.TextFormatting

                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedRun:
+                    case ShapedTextRun shapedRun:
                        {
                            currentWidth += shapedRun.Size.Width;

--- a/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextFormatterImpl.cs
@ -124,7 +124,7 @@ namespace Avalonia.Media.TextFormatting

                    var second = new List<DrawableTextRun>(secondCount);

-                    if (currentRun is ShapedTextCharacters shapedTextCharacters)
+                    if (currentRun is ShapedTextRun shapedTextCharacters)
                    {
                        var split = shapedTextCharacters.Split(length - currentLength);

@ -206,16 +206,16 @@ namespace Avalonia.Media.TextFormatting
                            break;
                        }

-                    case ShapeableTextCharacters shapeableRun:
+                    case UnshapedTextRun shapeableRun:
                        {
-                            var groupedRuns = new List<ShapeableTextCharacters>(2) { shapeableRun };
+                            var groupedRuns = new List<UnshapedTextRun>(2) { shapeableRun };
                            var characterBufferReference = currentRun.CharacterBufferReference;
                            var length = currentRun.Length;
                            var offsetToFirstCharacter = characterBufferReference.OffsetToFirstChar;

                            while (index + 1 < processedRuns.Count)
                            {
-                                if (processedRuns[index + 1] is not ShapeableTextCharacters nextRun)
+                                if (processedRuns[index + 1] is not UnshapedTextRun nextRun)
                                {
                                    break;
                                }
@ -258,10 +258,10 @@ namespace Avalonia.Media.TextFormatting
            return drawableTextRuns;
        }

-        private static IReadOnlyList<ShapedTextCharacters> ShapeTogether(
-            IReadOnlyList<ShapeableTextCharacters> textRuns, CharacterBufferReference text, int length, TextShaperOptions options)
+        private static IReadOnlyList<ShapedTextRun> ShapeTogether(
+            IReadOnlyList<UnshapedTextRun> textRuns, CharacterBufferReference text, int length, TextShaperOptions options)
        {
-            var shapedRuns = new List<ShapedTextCharacters>(textRuns.Count);
+            var shapedRuns = new List<ShapedTextRun>(textRuns.Count);

            var shapedBuffer = TextShaper.Current.ShapeText(text, length, options);

@ -271,7 +271,7 @@ namespace Avalonia.Media.TextFormatting

                var splitResult = shapedBuffer.Split(currentRun.Length);

-                shapedRuns.Add(new ShapedTextCharacters(splitResult.First, currentRun.Properties));
+                shapedRuns.Add(new ShapedTextRun(splitResult.First, currentRun.Properties));

                shapedBuffer = splitResult.Second!;
            }
@ -280,9 +280,9 @@ namespace Avalonia.Media.TextFormatting
        }

        /// <summary>
-        /// Coalesces ranges of the same bidi level to form <see cref="ShapeableTextCharacters"/>
+        /// Coalesces ranges of the same bidi level to form <see cref="UnshapedTextRun"/>
        /// </summary>
-        /// <param name="textCharacters">The text characters to form <see cref="ShapeableTextCharacters"/> from.</param>
+        /// <param name="textCharacters">The text characters to form <see cref="UnshapedTextRun"/> from.</param>
        /// <param name="levels">The bidi levels.</param>
        /// <returns></returns>
        private static IEnumerable<IReadOnlyList<TextRun>> CoalesceLevels(IReadOnlyList<TextRun> textCharacters, ArraySlice<sbyte> levels)
@ -474,7 +474,7 @@ namespace Avalonia.Media.TextFormatting
            {
                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedTextCharacters:
+                    case ShapedTextRun shapedTextCharacters:
                        {
                            if(shapedTextCharacters.ShapedBuffer.Length > 0)
                            {
@ -538,7 +538,7 @@ namespace Avalonia.Media.TextFormatting
            var shapedBuffer = new ShapedBuffer(characterBufferRange, glyphInfos, glyphTypeface, properties.FontRenderingEmSize,
                (sbyte)flowDirection);

-            var textRuns = new List<DrawableTextRun> { new ShapedTextCharacters(shapedBuffer, properties) };
+            var textRuns = new List<DrawableTextRun> { new ShapedTextRun(shapedBuffer, properties) };

            return new TextLineImpl(textRuns, firstTextSourceIndex, 0, paragraphWidth, paragraphProperties, flowDirection).FinalizeLine();
        }
@ -744,7 +744,7 @@ namespace Avalonia.Media.TextFormatting
        /// <returns>
        /// The shaped symbol.
        /// </returns>
-        internal static ShapedTextCharacters CreateSymbol(TextRun textRun, FlowDirection flowDirection)
+        internal static ShapedTextRun CreateSymbol(TextRun textRun, FlowDirection flowDirection)
        {
            var textShaper = TextShaper.Current;

@ -760,7 +760,7 @@ namespace Avalonia.Media.TextFormatting

            var shapedBuffer = textShaper.ShapeText(characterBuffer, textRun.Length, shaperOptions);

-            return new ShapedTextCharacters(shapedBuffer, textRun.Properties);
+            return new ShapedTextRun(shapedBuffer, textRun.Properties);
        }
    }
 }
--- a/src/Avalonia.Base/Media/TextFormatting/TextLeadingPrefixCharacterEllipsis.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextLeadingPrefixCharacterEllipsis.cs
@ -65,7 +65,7 @@ namespace Avalonia.Media.TextFormatting

                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedRun:
+                    case ShapedTextRun shapedRun:
                    {
                        currentWidth += currentRun.Size.Width;

@ -118,7 +118,7 @@ namespace Avalonia.Media.TextFormatting

                                    switch (run)
                                    {
-                                        case ShapedTextCharacters endShapedRun:
+                                        case ShapedTextRun endShapedRun:
                                        {
                                            if (endShapedRun.TryMeasureCharactersBackwards(availableSuffixWidth,
                                                    out var suffixCount, out var suffixWidth))
--- a/src/Avalonia.Base/Media/TextFormatting/TextLineImpl.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextLineImpl.cs
@ -192,14 +192,14 @@ namespace Avalonia.Media.TextFormatting
            {
                var currentRun = _textRuns[i];

-                if (currentRun is ShapedTextCharacters shapedRun && !shapedRun.ShapedBuffer.IsLeftToRight)
+                if (currentRun is ShapedTextRun shapedRun && !shapedRun.ShapedBuffer.IsLeftToRight)
                {
                    var rightToLeftIndex = i;
                    currentPosition += currentRun.Length;

                    while (rightToLeftIndex + 1 <= _textRuns.Count - 1)
                    {
-                        var nextShaped = _textRuns[++rightToLeftIndex] as ShapedTextCharacters;
+                        var nextShaped = _textRuns[++rightToLeftIndex] as ShapedTextRun;

                        if (nextShaped == null || nextShaped.ShapedBuffer.IsLeftToRight)
                        {
@ -255,7 +255,7 @@ namespace Avalonia.Media.TextFormatting

            switch (run)
            {
-                case ShapedTextCharacters shapedRun:
+                case ShapedTextRun shapedRun:
                    {
                        characterHit = shapedRun.GlyphRun.GetCharacterHitFromDistance(distance, out _);

@ -303,7 +303,7 @@ namespace Avalonia.Media.TextFormatting
                {
                    var currentRun = _textRuns[index];

-                    if (currentRun is ShapedTextCharacters shapedRun && !shapedRun.ShapedBuffer.IsLeftToRight)
+                    if (currentRun is ShapedTextRun shapedRun && !shapedRun.ShapedBuffer.IsLeftToRight)
                    {
                        var i = index;

@ -313,7 +313,7 @@ namespace Avalonia.Media.TextFormatting
                        {
                            var nextRun = _textRuns[i + 1];

-                            if (nextRun is ShapedTextCharacters nextShapedRun && !nextShapedRun.ShapedBuffer.IsLeftToRight)
+                            if (nextRun is ShapedTextRun nextShapedRun && !nextShapedRun.ShapedBuffer.IsLeftToRight)
                            {
                                i++;

@ -407,7 +407,7 @@ namespace Avalonia.Media.TextFormatting

            switch (currentRun)
            {
-                case ShapedTextCharacters shapedTextCharacters:
+                case ShapedTextRun shapedTextCharacters:
                    {
                        currentGlyphRun = shapedTextCharacters.GlyphRun;

@ -476,7 +476,7 @@ namespace Avalonia.Media.TextFormatting

            switch (currentRun)
            {
-                case ShapedTextCharacters shapedRun:
+                case ShapedTextRun shapedRun:
                    {
                        nextCharacterHit = shapedRun.GlyphRun.GetNextCaretCharacterHit(characterHit);
                        break;
@ -550,7 +550,7 @@ namespace Avalonia.Media.TextFormatting

                double combinedWidth;

-                if (currentRun is ShapedTextCharacters currentShapedRun)
+                if (currentRun is ShapedTextRun currentShapedRun)
                {
                    var firstCluster = currentShapedRun.GlyphRun.Metrics.FirstCluster;

@ -592,7 +592,7 @@ namespace Avalonia.Media.TextFormatting
                        var rightToLeftIndex = index;
                        var rightToLeftWidth = currentShapedRun.Size.Width;

-                        while (rightToLeftIndex + 1 <= _textRuns.Count - 1 && _textRuns[rightToLeftIndex + 1] is ShapedTextCharacters nextShapedRun)
+                        while (rightToLeftIndex + 1 <= _textRuns.Count - 1 && _textRuns[rightToLeftIndex + 1] is ShapedTextRun nextShapedRun)
                        {
                            if (nextShapedRun == null || nextShapedRun.ShapedBuffer.IsLeftToRight)
                            {
@ -624,12 +624,12 @@ namespace Avalonia.Media.TextFormatting

                        for (int i = rightToLeftIndex - 1; i >= index; i--)
                        {
-                            if (TextRuns[i] is not ShapedTextCharacters)
+                            if (TextRuns[i] is not ShapedTextRun)
                            {
                                continue;
                            }

-                            currentShapedRun = (ShapedTextCharacters)TextRuns[i];
+                            currentShapedRun = (ShapedTextRun)TextRuns[i];

                            currentRunBounds = GetRightToLeftTextRunBounds(currentShapedRun, startX, firstTextSourceIndex, characterIndex, currentPosition, remainingLength);

@ -769,7 +769,7 @@ namespace Avalonia.Media.TextFormatting
                var characterLength = 0;
                var endX = startX;

-                if (currentRun is ShapedTextCharacters currentShapedRun)
+                if (currentRun is ShapedTextRun currentShapedRun)
                {
                    var offset = Math.Max(0, firstTextSourceIndex - currentPosition);

@ -883,7 +883,7 @@ namespace Avalonia.Media.TextFormatting
            return result;
        }

-        private TextRunBounds GetRightToLeftTextRunBounds(ShapedTextCharacters currentRun, double endX, int firstTextSourceIndex, int characterIndex, int currentPosition, int remainingLength)
+        private TextRunBounds GetRightToLeftTextRunBounds(ShapedTextRun currentRun, double endX, int firstTextSourceIndex, int characterIndex, int currentPosition, int remainingLength)
        {
            var startX = endX;

@ -945,7 +945,7 @@ namespace Avalonia.Media.TextFormatting

        private static sbyte GetRunBidiLevel(DrawableTextRun run, FlowDirection flowDirection)
        {
-            if (run is ShapedTextCharacters shapedTextCharacters)
+            if (run is ShapedTextRun shapedTextCharacters)
            {
                return shapedTextCharacters.BidiLevel;
            }
@ -1027,7 +1027,7 @@ namespace Avalonia.Media.TextFormatting
                {
                    if (current.Level >= minLevelToReverse && current.Level % 2 != 0)
                    {
-                        if (current.Run is ShapedTextCharacters { IsReversed: false } shapedTextCharacters)
+                        if (current.Run is ShapedTextRun { IsReversed: false } shapedTextCharacters)
                        {
                            shapedTextCharacters.Reverse();
                        }
@ -1145,7 +1145,7 @@ namespace Avalonia.Media.TextFormatting

                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedRun:
+                    case ShapedTextRun shapedRun:
                        {
                            var foundCharacterHit = shapedRun.GlyphRun.FindNearestCharacterHit(characterHit.FirstCharacterIndex + characterHit.TrailingLength, out _);

@ -1230,7 +1230,7 @@ namespace Avalonia.Media.TextFormatting

                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedRun:
+                    case ShapedTextRun shapedRun:
                        {
                            var foundCharacterHit = shapedRun.GlyphRun.FindNearestCharacterHit(characterHit.FirstCharacterIndex - 1, out _);

@ -1294,7 +1294,7 @@ namespace Avalonia.Media.TextFormatting

                switch (currentRun)
                {
-                    case ShapedTextCharacters shapedRun:
+                    case ShapedTextRun shapedRun:
                        {
                            var firstCluster = shapedRun.GlyphRun.Metrics.FirstCluster;

@ -1303,7 +1303,7 @@ namespace Avalonia.Media.TextFormatting
                                break;
                            }

-                            if (previousRun is ShapedTextCharacters previousShaped && !previousShaped.ShapedBuffer.IsLeftToRight)
+                            if (previousRun is ShapedTextRun previousShaped && !previousShaped.ShapedBuffer.IsLeftToRight)
                            {
                                if (shapedRun.ShapedBuffer.IsLeftToRight)
                                {
@ -1394,7 +1394,7 @@ namespace Avalonia.Media.TextFormatting
            {
                switch (_textRuns[index])
                {
-                    case ShapedTextCharacters textRun:
+                    case ShapedTextRun textRun:
                        {
                            var textMetrics =
                                new TextMetrics(textRun.Properties.Typeface.GlyphTypeface, textRun.Properties.FontRenderingEmSize);
--- a/src/Avalonia.Base/Media/TextFormatting/TextParagraphProperties.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextParagraphProperties.cs
@ -63,14 +63,11 @@
        {
            get { return 0; }
        }
-        
+
        /// <summary>
        /// Gets the default incremental tab width.
        /// </summary>
-        public virtual double DefaultIncrementalTab
-        {
-            get { return 4 * DefaultTextRunProperties.FontRenderingEmSize; }
-        }
+        public virtual double DefaultIncrementalTab => 0;

        /// <summary>
        /// Gets the letter spacing.
--- a/src/Avalonia.Base/Media/TextFormatting/TextRun.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextRun.cs
@ -44,7 +44,7 @@ namespace Avalonia.Media.TextFormatting

                        fixed (char* charsPtr = characterBuffer.Span)
                        {
-                            return new string(charsPtr, 0, characterBuffer.Span.Length);
+                            return new string(charsPtr, _textRun.CharacterBufferReference.OffsetToFirstChar, _textRun.Length);
                        }
                    }
                }
--- a/src/Avalonia.Base/Media/TextFormatting/TextShaper.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/TextShaper.cs
@ -29,10 +29,7 @@ namespace Avalonia.Media.TextFormatting
                    return current;
                }

-                var textShaperImpl = AvaloniaLocator.Current.GetService<ITextShaperImpl>();
-
-                if (textShaperImpl == null)
-                    throw new InvalidOperationException("No text shaper implementation was registered.");
+                var textShaperImpl = AvaloniaLocator.Current.GetRequiredService<ITextShaperImpl>();

                current = new TextShaper(textShaperImpl);

--- a/src/Avalonia.Base/Media/TextFormatting/ShapeableTextCharacters.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/ShapeableTextCharacters.cs
@ -5,9 +5,9 @@ namespace Avalonia.Media.TextFormatting
    /// <summary>
    /// A group of characters that can be shaped.
    /// </summary>
-    public sealed class ShapeableTextCharacters : TextRun
+    public sealed class UnshapedTextRun : TextRun
    {
-        public ShapeableTextCharacters(CharacterBufferReference characterBufferReference, int length,
+        public UnshapedTextRun(CharacterBufferReference characterBufferReference, int length,
            TextRunProperties properties, sbyte biDiLevel)
        {
            CharacterBufferReference = characterBufferReference;
@ -24,30 +24,30 @@ namespace Avalonia.Media.TextFormatting

        public sbyte BidiLevel { get; }

-        public bool CanShapeTogether(ShapeableTextCharacters shapeableTextCharacters)
+        public bool CanShapeTogether(UnshapedTextRun unshapedTextRun)
        {
-            if (!CharacterBufferReference.Equals(shapeableTextCharacters.CharacterBufferReference))
+            if (!CharacterBufferReference.Equals(unshapedTextRun.CharacterBufferReference))
            {
                return false;
            }

-            if (BidiLevel != shapeableTextCharacters.BidiLevel)
+            if (BidiLevel != unshapedTextRun.BidiLevel)
            {
                return false;
            }

            if (!MathUtilities.AreClose(Properties.FontRenderingEmSize,
-                    shapeableTextCharacters.Properties.FontRenderingEmSize))
+                    unshapedTextRun.Properties.FontRenderingEmSize))
            {
                return false;
            }

-            if (Properties.Typeface != shapeableTextCharacters.Properties.Typeface)
+            if (Properties.Typeface != unshapedTextRun.Properties.Typeface)
            {
                return false;
            }

-            if (Properties.BaselineAlignment != shapeableTextCharacters.Properties.BaselineAlignment)
+            if (Properties.BaselineAlignment != unshapedTextRun.Properties.BaselineAlignment)
            {
                return false;
            }
--- a/src/Avalonia.Base/Rendering/Composition/Expressions/ExpressionVariant.cs
+++ b/src/Avalonia.Base/Rendering/Composition/Expressions/ExpressionVariant.cs
@ -654,7 +654,7 @@ namespace Avalonia.Rendering.Composition.Expressions
                }
            }

-            res = default(T);
+            res = default;
            return false;
        }

--- a/src/Avalonia.Base/Rendering/ImmediateRenderer.cs
+++ b/src/Avalonia.Base/Rendering/ImmediateRenderer.cs
@ -330,11 +330,11 @@ namespace Avalonia.Rendering
                    ? visual is IVisualWithRoundRectClip roundClipVisual
                        ? context.PushClip(new RoundedRect(bounds, roundClipVisual.ClipToBoundsRadius))
                        : context.PushClip(bounds) 
-                    : default(DrawingContext.PushedState))
+                    : default)
 #pragma warning restore CS0618 // Type or member is obsolete

-                using (visual.Clip != null ? context.PushGeometryClip(visual.Clip) : default(DrawingContext.PushedState))
-                using (visual.OpacityMask != null ? context.PushOpacityMask(visual.OpacityMask, bounds) : default(DrawingContext.PushedState))
+                using (visual.Clip != null ? context.PushGeometryClip(visual.Clip) : default)
+                using (visual.OpacityMask != null ? context.PushOpacityMask(visual.OpacityMask, bounds) : default)
                using (context.PushTransformContainer())
                {
                    visual.Render(context);
--- a/src/Avalonia.Base/Rendering/RenderLoop.cs
+++ b/src/Avalonia.Base/Rendering/RenderLoop.cs
@ -50,8 +50,7 @@ namespace Avalonia.Rendering
        {
            get
            {
-                return _timer ??= AvaloniaLocator.Current.GetService<IRenderTimer>() ??
-                    throw new InvalidOperationException("Cannot locate IRenderTimer.");
+                return _timer ??= AvaloniaLocator.Current.GetRequiredService<IRenderTimer>();
            }
        }

--- a/src/Avalonia.Base/Rendering/Utilities/TileBrushCalculator.cs
+++ b/src/Avalonia.Base/Rendering/Utilities/TileBrushCalculator.cs
@ -109,7 +109,7 @@ namespace Avalonia.Rendering.Utilities
            {
                if (IntermediateTransform != Matrix.Identity)
                    return true;
-                if (SourceRect.Position != default(Point))
+                if (SourceRect.Position != default)
                    return true;
                if (SourceRect.Size.AspectRatio == _imageSize.AspectRatio)
                    return false;
--- a/src/Avalonia.Base/Threading/DispatcherTimer.cs
+++ b/src/Avalonia.Base/Threading/DispatcherTimer.cs
@ -176,13 +176,7 @@ namespace Avalonia.Threading
        {
            if (!IsEnabled)
            {
-                var threading = AvaloniaLocator.Current.GetService<IPlatformThreadingInterface>();
-
-                if (threading == null)
-                {
-                    throw new Exception("Could not start timer: IPlatformThreadingInterface is not registered.");
-                }
-
+                var threading = AvaloniaLocator.Current.GetRequiredService<IPlatformThreadingInterface>();
                _timer = threading.StartTimer(_priority, Interval, InternalTick);
            }
        }
--- a/src/Avalonia.Base/Utilities/SingleOrDictionary.cs
+++ b/src/Avalonia.Base/Utilities/SingleOrDictionary.cs
@ -42,7 +42,7 @@ namespace Avalonia.Utilities
            {
                if (!_singleValue.HasValue || !EqualityComparer<TKey>.Default.Equals(_singleValue.Value.Key, key))
                {
-                    value = default(TValue);
+                    value = default;
                    return false;
                }
                else
--- a/src/Avalonia.Base/Utilities/StringTokenizer.cs
+++ b/src/Avalonia.Base/Utilities/StringTokenizer.cs
@ -63,7 +63,7 @@ namespace Avalonia.Utilities
            }
            else
            {
-                result = default(Int32);
+                result = default;
                return false;
            }
        }
@ -87,7 +87,7 @@ namespace Avalonia.Utilities
            }
            else
            {
-                result = default(double);
+                result = default;
                return false;
            }
        }
--- a/src/Avalonia.Base/Visual.cs
+++ b/src/Avalonia.Base/Visual.cs
@ -480,6 +480,7 @@ namespace Avalonia
            {
                AttachToCompositor(compositingRenderer.Compositor);
            }
+            InvalidateMirrorTransform();
            OnAttachedToVisualTree(e);
            AttachedToVisualTree?.Invoke(this, e);
            InvalidateVisual();
--- a/src/Avalonia.Controls.DataGrid/DataGrid.cs
+++ b/src/Avalonia.Controls.DataGrid/DataGrid.cs
@ -1118,7 +1118,7 @@ namespace Avalonia.Controls
                    EnsureColumnHeadersVisibility();
                    if (!newValueCols)
                    {
-                        _columnHeadersPresenter.Measure(default(Size));
+                        _columnHeadersPresenter.Measure(default);
                    }
                    else
                    {
@ -1159,7 +1159,7 @@ namespace Avalonia.Controls
                _topLeftCornerHeader.IsVisible = newValueRows && newValueCols;
                if (_topLeftCornerHeader.IsVisible)
                {
-                    _topLeftCornerHeader.Measure(default(Size));
+                    _topLeftCornerHeader.Measure(default);
                }
            }

--- a/src/Avalonia.Controls.DataGrid/IndexToValueTable.cs
+++ b/src/Avalonia.Controls.DataGrid/IndexToValueTable.cs
@ -422,7 +422,7 @@ namespace Avalonia.Controls
            else
            {
                found = false;
-                return default(T);
+                return default;
            }
        }

--- a/src/Avalonia.Controls/Control.cs
+++ b/src/Avalonia.Controls/Control.cs
@ -392,14 +392,6 @@ namespace Avalonia.Controls
            OnUnloadedCore();
        }

-        /// <inheritdoc/>
-        protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
-        {
-            base.OnAttachedToVisualTree(e);
-
-            InvalidateMirrorTransform();
-        }
-
        /// <inheritdoc/>
        protected override void OnGotFocus(GotFocusEventArgs e)
        {
--- a/src/Avalonia.Controls/Platform/InProcessDragSource.cs
+++ b/src/Avalonia.Controls/Platform/InProcessDragSource.cs
@ -41,7 +41,7 @@ namespace Avalonia.Platform
            {
                _draggedData = data;
                _lastRoot = null;
-                _lastPosition = default(Point);
+                _lastPosition = default;
                _allowedEffects = allowedEffects;

                using (_inputManager.PreProcess.OfType<RawPointerEventArgs>().Subscribe(ProcessMouseEvents))
--- a/src/Avalonia.Controls/Platform/PlatformManager.cs
+++ b/src/Avalonia.Controls/Platform/PlatformManager.cs
@ -26,21 +26,14 @@ namespace Avalonia.Controls.Platform

        public static IWindowImpl CreateWindow()
        {
-            var platform = AvaloniaLocator.Current.GetService<IWindowingPlatform>();
-            
-            if (platform == null)
-            {
-                throw new Exception("Could not CreateWindow(): IWindowingPlatform is not registered.");
-            }
+            var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();

            return s_designerMode ? platform.CreateEmbeddableWindow() : platform.CreateWindow();
        }

        public static IWindowImpl CreateEmbeddableWindow()
        {
-            var platform = AvaloniaLocator.Current.GetService<IWindowingPlatform>();
-            if (platform == null)
-                throw new Exception("Could not CreateEmbeddableWindow(): IWindowingPlatform is not registered.");
+            var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
            return platform.CreateEmbeddableWindow();
        }
    }
--- a/src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs
+++ b/src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs
@ -501,7 +501,7 @@ namespace Avalonia.Controls.Presenters

            if (e.OldValue != null)
            {
-                Offset = default(Vector);
+                Offset = default;
            }
        }

@ -543,7 +543,7 @@ namespace Avalonia.Controls.Presenters
            if (logicalScroll != scrollable.IsLogicalScrollEnabled)
            {
                UpdateScrollableSubscription(Child);
-                Offset = default(Vector);
+                Offset = default;
                InvalidateMeasure();
            }
            else if (scrollable.IsLogicalScrollEnabled)
--- a/src/Avalonia.Controls/Utils/UndoRedoHelper.cs
+++ b/src/Avalonia.Controls/Utils/UndoRedoHelper.cs
@ -49,7 +49,7 @@ namespace Avalonia.Controls.Utils

        public bool TryGetLastState(out TState? _state)
        {
-            _state = default(TState);
+            _state = default;
            if (!IsLastState)
                return false;

--- a/src/Avalonia.DesignerSupport/DesignWindowLoader.cs
+++ b/src/Avalonia.DesignerSupport/DesignWindowLoader.cs
@ -18,12 +18,9 @@ namespace Avalonia.DesignerSupport
            Control control;
            using (PlatformManager.DesignerMode())
            {
-                var loader = AvaloniaLocator.Current.GetService<AvaloniaXamlLoader.IRuntimeXamlLoader>();
+                var loader = AvaloniaLocator.Current.GetRequiredService<AvaloniaXamlLoader.IRuntimeXamlLoader>();
                var stream = new MemoryStream(Encoding.UTF8.GetBytes(xaml));

-                if (loader == null)
-                    throw new XamlLoadException("Runtime XAML loader is not registered");
-                
                Uri baseUri = null;
                if (assemblyPath != null)
                {
--- a/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs
+++ b/src/Avalonia.Dialogs/Internal/ManagedFileChooserViewModel.cs
@ -117,7 +117,7 @@ namespace Avalonia.Dialogs.Internal
                                              ?? new ManagedFileChooserSources();

            var sub1 = AvaloniaLocator.Current
-                                      .GetService<IMountedVolumeInfoProvider>()
+                                      .GetRequiredService<IMountedVolumeInfoProvider>()
                                      .Listen(ManagedFileChooserSources.MountedVolumes);

            var sub2 = Observable.FromEventPattern(ManagedFileChooserSources.MountedVolumes,
--- a/src/Avalonia.FreeDesktop/DBusMenu.cs
+++ b/src/Avalonia.FreeDesktop/DBusMenu.cs
@ -36,10 +36,10 @@ namespace Avalonia.FreeDesktop.DBusMenu
    [Dictionary]
    class DBusMenuProperties
    {
-        public uint Version { get; set; } = default (uint);
-        public string? TextDirection { get; set; } = default (string);
-        public string? Status { get; set; } = default (string);
-        public string[]? IconThemePath { get; set; } = default (string[]);
+        public uint Version { get; set; } = default;
+        public string? TextDirection { get; set; } = default;
+        public string? Status { get; set; } = default;
+        public string[]? IconThemePath { get; set; } = default;
    }


--- a/src/Avalonia.OpenGL/Egl/EglInterface.cs
+++ b/src/Avalonia.OpenGL/Egl/EglInterface.cs
@ -35,7 +35,7 @@ namespace Avalonia.OpenGL.Egl

        static Func<string, IntPtr> Load(string library)
        {
-            var dyn = AvaloniaLocator.Current.GetService<IDynamicLibraryLoader>();
+            var dyn = AvaloniaLocator.Current.GetRequiredService<IDynamicLibraryLoader>();
            var lib = dyn.LoadLibrary(library);
            return (s) => dyn.GetProcAddress(lib, s, true);
        }
--- a/src/Avalonia.X11/X11Framebuffer.cs
+++ b/src/Avalonia.X11/X11Framebuffer.cs
@ -25,7 +25,7 @@ namespace Avalonia.X11
            RowBytes = width * 4;
            Dpi = new Vector(96, 96) * factor;
            Format = PixelFormat.Bgra8888;
-            _blob = AvaloniaLocator.Current.GetService<IRuntimePlatform>().AllocBlob(RowBytes * height);
+            _blob = AvaloniaLocator.Current.GetRequiredService<IRuntimePlatform>().AllocBlob(RowBytes * height);
            Address = _blob.Address;
        }
        
--- a/src/Avalonia.X11/X11Platform.cs
+++ b/src/Avalonia.X11/X11Platform.cs
@ -105,7 +105,7 @@ namespace Avalonia.X11
            var gl = AvaloniaLocator.Current.GetService<IPlatformGraphics>();
            
            if (options.UseCompositor)
-                Compositor = new Compositor(AvaloniaLocator.Current.GetService<IRenderLoop>()!, gl);
+                Compositor = new Compositor(AvaloniaLocator.Current.GetRequiredService<IRenderLoop>(), gl);
            else
                RenderInterface = new(gl);

--- a/src/Browser/Avalonia.Browser/AvaloniaView.cs
+++ b/src/Browser/Avalonia.Browser/AvaloniaView.cs
@ -106,7 +106,7 @@ namespace Avalonia.Browser

            _dpi = DomHelper.ObserveDpi(OnDpiChanged);

-            _useGL = AvaloniaLocator.Current.GetRequiredService<IPlatformGraphics>() != null;
+            _useGL = AvaloniaLocator.Current.GetService<IPlatformGraphics>() != null;

            if (_useGL)
            {
--- a/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs
+++ b/src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs
@ -25,7 +25,7 @@ namespace Avalonia.LinuxFramebuffer

            Surfaces = new object[] { _outputBackend };

-            Invalidate(default(Rect));
+            Invalidate(default);
            _inputBackend.Initialize(this, e => Input?.Invoke(e));
        }

--- a/src/Markup/Avalonia.Markup.Xaml/Converters/BitmapTypeConverter.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/Converters/BitmapTypeConverter.cs
@ -24,7 +24,7 @@ namespace Avalonia.Markup.Xaml.Converters
            if(uri.IsAbsoluteUri && uri.IsFile)
                return new Bitmap(uri.LocalPath);

-            var assets = AvaloniaLocator.Current.GetService<IAssetLoader>();
+            var assets = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
            return new Bitmap(assets.Open(uri, context.GetContextBaseUri()));
        }
    }
--- a/src/Markup/Avalonia.Markup.Xaml/Converters/IconTypeConverter.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/Converters/IconTypeConverter.cs
@ -40,7 +40,7 @@ namespace Avalonia.Markup.Xaml.Converters
            
            if(uri.IsAbsoluteUri && uri.IsFile)
                return new WindowIcon(uri.LocalPath);
-            var assets = AvaloniaLocator.Current.GetService<IAssetLoader>();
+            var assets = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();
            return new WindowIcon(assets.Open(uri, context.GetContextBaseUri()));
        }
    }
--- a/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
+++ b/src/Skia/Avalonia.Skia/DrawingContextImpl.cs
@ -224,9 +224,9 @@ namespace Avalonia.Skia
            var impl = (GeometryImpl) geometry;
            var size = geometry.Bounds.Size;

-            using (var fill = brush != null ? CreatePaint(_fillPaint, brush, size) : default(PaintWrapper))
+            using (var fill = brush != null ? CreatePaint(_fillPaint, brush, size) : default)
            using (var stroke = pen?.Brush != null ? CreatePaint(_strokePaint, pen, 
-                size.Inflate(new Thickness(pen?.Thickness / 2 ?? 0))) : default(PaintWrapper))
+                size.Inflate(new Thickness(pen?.Thickness / 2 ?? 0))) : default)
            {
                if (fill.Paint != null)
                {
--- a/src/Skia/Avalonia.Skia/GeometryImpl.cs
+++ b/src/Skia/Avalonia.Skia/GeometryImpl.cs
@ -245,7 +245,7 @@ namespace Avalonia.Skia
            {
                CachedStrokePath?.Dispose();
                CachedGeometryRenderBounds = default;
-                _cachedStrokeWidth = default(float);
+                _cachedStrokeWidth = default;
            }
        }
    }
--- a/src/Skia/Avalonia.Skia/SKTypefaceCollectionCache.cs
+++ b/src/Skia/Avalonia.Skia/SKTypefaceCollectionCache.cs
@ -37,7 +37,7 @@ namespace Avalonia.Skia

            var typeFaceCollection = new SKTypefaceCollection();

-            var assetLoader = AvaloniaLocator.Current.GetService<IAssetLoader>();
+            var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();

            foreach (var asset in fontAssets)
            {
--- a/src/Skia/Avalonia.Skia/WriteableBitmapImpl.cs
+++ b/src/Skia/Avalonia.Skia/WriteableBitmapImpl.cs
@ -96,9 +96,9 @@ namespace Avalonia.Skia

            SKColorType colorType = format.ToSkColorType();
            SKAlphaType alphaType = alphaFormat.ToSkAlphaType();
-            
-            var runtimePlatform = AvaloniaLocator.Current?.GetService<IRuntimePlatform>();
-            
+
+            var runtimePlatform = AvaloniaLocator.Current.GetService<IRuntimePlatform>();
+
            if (runtimePlatform != null)
            {
                _bitmap = new SKBitmap();
--- a/src/Windows/Avalonia.Direct2D1/Media/DWriteResourceFontLoader.cs
+++ b/src/Windows/Avalonia.Direct2D1/Media/DWriteResourceFontLoader.cs
@ -22,7 +22,7 @@ namespace Avalonia.Direct2D1.Media
        {
            var factory1 = factory;

-            var assetLoader = AvaloniaLocator.Current.GetService<IAssetLoader>();
+            var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();

            foreach (var asset in fontAssets)
            {
--- a/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs
+++ b/src/Windows/Avalonia.Direct2D1/Media/DrawingContextImpl.cs
@ -409,7 +409,7 @@ namespace Avalonia.Direct2D1.Media
            }
            else
            {
-                var platform = AvaloniaLocator.Current.GetService<IPlatformRenderInterface>();
+                var platform = AvaloniaLocator.Current.GetRequiredService<IPlatformRenderInterface>();
                var dpi = new Vector(_deviceContext.DotsPerInch.Width, _deviceContext.DotsPerInch.Height);
                var pixelSize = PixelSize.FromSizeWithDpi(size, dpi);
                return (IDrawingContextLayerImpl)platform.CreateRenderTargetBitmap(pixelSize, dpi);
--- a/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs
+++ b/src/Windows/Avalonia.Win32.Interop/Wpf/Direct2DImageSurface.cs
@ -127,7 +127,7 @@ namespace Avalonia.Win32.Interop.Wpf
                DeviceWindowHandle = GetDesktopWindow(),
                PresentationInterval = PresentInterval.Default
            };
-            s_dxDevice = s_dxDevice ?? AvaloniaLocator.Current.GetService<SharpDX.DXGI.Device>()
+            s_dxDevice = s_dxDevice ?? AvaloniaLocator.Current.GetRequiredService<SharpDX.DXGI.Device>()
                             .QueryInterface<SharpDX.Direct3D11.Device>();
            s_d3DDevice = new DeviceEx(s_d3DContext, 0, DeviceType.Hardware, IntPtr.Zero, CreateFlags.HardwareVertexProcessing | CreateFlags.Multithreaded | CreateFlags.FpuPreserve, presentparams);

@ -156,7 +156,7 @@ namespace Avalonia.Win32.Interop.Wpf
            _impl.ImageSource = _image;

            RemoveAndDispose(ref _backBuffer);
-            if (size == default(IntSize))
+            if (size == default)
            {
                _image.Lock();
                _image.SetBackBuffer(D3DResourceType.IDirect3DSurface9, IntPtr.Zero);
@ -171,7 +171,7 @@ namespace Avalonia.Win32.Interop.Wpf
        static void RemoveAndDispose<T>(ref T d) where T : IDisposable
        {
            d?.Dispose();
-            d = default(T);
+            d = default;
        }

        void Swap()
--- a/src/Windows/Avalonia.Win32/DataObject.cs
+++ b/src/Windows/Avalonia.Win32/DataObject.cs
@ -205,7 +205,7 @@ namespace Avalonia.Win32
            if (string.IsNullOrEmpty(fmt) || !_wrapped.Contains(fmt))
                return DV_E_FORMATETC;

-            * medium = default(Interop.STGMEDIUM);
+            * medium = default;
            medium->tymed = TYMED.TYMED_HGLOBAL;
            return WriteDataToHGlobal(fmt, ref medium->unionmember);
        }
--- a/src/Windows/Avalonia.Win32/OleDropTarget.cs
+++ b/src/Windows/Avalonia.Win32/OleDropTarget.cs
@ -121,7 +121,7 @@ namespace Avalonia.Win32
                    _dragDevice,
                    RawDragEventType.DragLeave,
                    _target,
-                    default(Point),
+                    default,
                    null,
                    DragDropEffects.None,
                    RawInputModifiers.None
--- a/tests/Avalonia.Base.UnitTests/Media/Fonts/FontFamilyLoaderTests.cs
+++ b/tests/Avalonia.Base.UnitTests/Media/Fonts/FontFamilyLoaderTests.cs
@ -97,7 +97,7 @@ namespace Avalonia.Base.UnitTests.Media.Fonts
        {
            using (UnitTestApplication.Start(TestServices.MockPlatformRenderInterface))
            {
-                var assetLoader = AvaloniaLocator.Current.GetService<IAssetLoader>();
+                var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();

                var fontFamily = new FontFamily("resm:Avalonia.Base.UnitTests.Assets?assembly=Avalonia.Base.UnitTests#Noto Mono");

--- a/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/ContextMenuTests.cs
@ -596,7 +596,7 @@ namespace Avalonia.Controls.UnitTests
        private static Window PreparedWindow(object content = null)
        {
            var renderer = new Mock<IRenderer>();
-            var platform = AvaloniaLocator.Current.GetService<IWindowingPlatform>();
+            var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
            var windowImpl = Mock.Get(platform.CreateWindow());
            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);

--- a/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/FlyoutTests.cs
@ -570,7 +570,7 @@ namespace Avalonia.Controls.UnitTests
        private static Window PreparedWindow(object content = null)
        {
            var renderer = new Mock<IRenderer>();
-            var platform = AvaloniaLocator.Current.GetService<IWindowingPlatform>();
+            var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
            var windowImpl = Mock.Get(platform.CreateWindow());
            windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);

--- a/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/MaskedTextBoxTests.cs
@ -827,7 +827,7 @@ namespace Avalonia.Controls.UnitTests
                {
                    AvaloniaLocator.CurrentMutable.Bind<IClipboard>().ToSingleton<ClipboardStub>();

-                    var clipboard = AvaloniaLocator.CurrentMutable.GetService<IClipboard>();
+                    var clipboard = AvaloniaLocator.CurrentMutable.GetRequiredService<IClipboard>();
                    clipboard.SetTextAsync(textInput).GetAwaiter().GetResult();

                    RaiseKeyEvent(target, Key.V, KeyModifiers.Control);
--- a/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs
+++ b/tests/Avalonia.Controls.UnitTests/Presenters/ItemsPresenterTests_Virtualization_Simple.cs
@ -569,7 +569,7 @@ namespace Avalonia.Controls.UnitTests.Presenters
                var target = CreateTarget(itemCount: 10);
                var items = (IList<string>)target.Items;
                target.ApplyTemplate();
-                target.Measure(default(Size));
+                target.Measure(default);
                target.Arrange(default);

                // Check for issue #591: this should not throw.
--- a/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/Primitives/PopupTests.cs
@ -564,7 +564,7 @@ namespace Avalonia.Controls.UnitTests.Primitives
            using (CreateServices())
            {
                var renderer = new Mock<IRenderer>();
-                var platform = AvaloniaLocator.Current.GetService<IWindowingPlatform>();
+                var platform = AvaloniaLocator.Current.GetRequiredService<IWindowingPlatform>();
                var windowImpl = Mock.Get(platform.CreateWindow());
                windowImpl.Setup(x => x.CreateRenderer(It.IsAny<IRenderRoot>())).Returns(renderer.Object);

--- a/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TextBoxTests.cs
@ -767,7 +767,7 @@ namespace Avalonia.Controls.UnitTests
                {
                    AvaloniaLocator.CurrentMutable.Bind<IClipboard>().ToSingleton<ClipboardStub>();
                    
-                    var clipboard = AvaloniaLocator.CurrentMutable.GetService<IClipboard>();
+                    var clipboard = AvaloniaLocator.CurrentMutable.GetRequiredService<IClipboard>();
                    clipboard.SetTextAsync(textInput).GetAwaiter().GetResult();

                    RaiseKeyEvent(target, Key.V, KeyModifiers.Control);
@ -876,7 +876,7 @@ namespace Avalonia.Controls.UnitTests

                AvaloniaLocator.CurrentMutable.Bind<IClipboard>().ToSingleton<ClipboardStub>();

-                var clipboard = AvaloniaLocator.CurrentMutable.GetService<IClipboard>();
+                var clipboard = AvaloniaLocator.CurrentMutable.GetRequiredService<IClipboard>();
                clipboard.SetTextAsync(Environment.NewLine).GetAwaiter().GetResult();

                RaiseKeyEvent(target, Key.V, KeyModifiers.Control);
--- a/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
+++ b/tests/Avalonia.Controls.UnitTests/TreeViewTests.cs
@ -1248,7 +1248,7 @@ namespace Avalonia.Controls.UnitTests
            using (Application())
            {
                var focus = FocusManager.Instance;
-                var navigation = AvaloniaLocator.Current.GetService<IKeyboardNavigationHandler>();
+                var navigation = AvaloniaLocator.Current.GetRequiredService<IKeyboardNavigationHandler>();
                var data = CreateTestTreeData();

                var target = new TreeView
@ -1293,7 +1293,6 @@ namespace Avalonia.Controls.UnitTests
            using (Application())
            {
                var focus = FocusManager.Instance;
-                var navigation = AvaloniaLocator.Current.GetService<IKeyboardNavigationHandler>();
                var data = CreateTestTreeData();

                var selectedNode = new Node { Value = "Out of Tree Selected Item" };
@ -1353,7 +1352,7 @@ namespace Avalonia.Controls.UnitTests

                var rootNode = tree[0];

-                var keymap = AvaloniaLocator.Current.GetService<PlatformHotkeyConfiguration>();
+                var keymap = AvaloniaLocator.Current.GetRequiredService<PlatformHotkeyConfiguration>();
                var selectAllGesture = keymap.SelectAll.First();

                var keyEvent = new KeyEventArgs
@ -1400,7 +1399,7 @@ namespace Avalonia.Controls.UnitTests
                ClickContainer(fromContainer, KeyModifiers.None);
                ClickContainer(toContainer, KeyModifiers.Shift);

-                var keymap = AvaloniaLocator.Current.GetService<PlatformHotkeyConfiguration>();
+                var keymap = AvaloniaLocator.Current.GetRequiredService<PlatformHotkeyConfiguration>();
                var selectAllGesture = keymap.SelectAll.First();

                var keyEvent = new KeyEventArgs
@ -1447,7 +1446,7 @@ namespace Avalonia.Controls.UnitTests
                ClickContainer(fromContainer, KeyModifiers.None);
                ClickContainer(toContainer, KeyModifiers.Shift);

-                var keymap = AvaloniaLocator.Current.GetService<PlatformHotkeyConfiguration>();
+                var keymap = AvaloniaLocator.Current.GetRequiredService<PlatformHotkeyConfiguration>();
                var selectAllGesture = keymap.SelectAll.First();

                var keyEvent = new KeyEventArgs
--- a/tests/Avalonia.ReactiveUI.UnitTests/AutoSuspendHelperTest.cs
+++ b/tests/Avalonia.ReactiveUI.UnitTests/AutoSuspendHelperTest.cs
@ -47,7 +47,7 @@ namespace Avalonia.ReactiveUI.UnitTests
            using (var lifetime = new ClassicDesktopStyleApplicationLifetime())
            {
                var isLaunchingReceived = false;
-                var application = AvaloniaLocator.Current.GetService<Application>();
+                var application = AvaloniaLocator.Current.GetRequiredService<Application>();
                application.ApplicationLifetime = lifetime;

                // Initialize ReactiveUI Suspension as in real-world scenario.
@ -65,7 +65,7 @@ namespace Avalonia.ReactiveUI.UnitTests
            using (UnitTestApplication.Start(TestServices.MockWindowingPlatform))
            using (var lifetime = new ExoticApplicationLifetimeWithoutLifecycleEvents()) 
            {
-                var application = AvaloniaLocator.Current.GetService<Application>();
+                var application = AvaloniaLocator.Current.GetRequiredService<Application>();
                application.ApplicationLifetime = lifetime;
                Assert.Throws<NotSupportedException>(() => new AutoSuspendHelper(application.ApplicationLifetime));
            }
@ -88,7 +88,7 @@ namespace Avalonia.ReactiveUI.UnitTests
            using (var lifetime = new ClassicDesktopStyleApplicationLifetime()) 
            {
                var shouldPersistReceived = false;
-                var application = AvaloniaLocator.Current.GetService<Application>();
+                var application = AvaloniaLocator.Current.GetRequiredService<Application>();
                application.ApplicationLifetime = lifetime;

                // Initialize ReactiveUI Suspension as in real-world scenario.
--- a/tests/Avalonia.RenderTests/TestBase.cs
+++ b/tests/Avalonia.RenderTests/TestBase.cs
@ -91,7 +91,7 @@ namespace Avalonia.Direct2D1.RenderTests
            var immediatePath = Path.Combine(OutputPath, testName + ".immediate.out.png");
            var deferredPath = Path.Combine(OutputPath, testName + ".deferred.out.png");
            var compositedPath = Path.Combine(OutputPath, testName + ".composited.out.png");
-            var factory = AvaloniaLocator.Current.GetService<IPlatformRenderInterface>();
+            var factory = AvaloniaLocator.Current.GetRequiredService<IPlatformRenderInterface>();
            var pixelSize = new PixelSize((int)target.Width, (int)target.Height);
            var size = new Size(target.Width, target.Height);
            var dpiVector = new Vector(dpi, dpi);
--- a/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextFormatterTests.cs
@ -520,7 +520,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                var expectedTextLine = formatter.FormatLine(new SingleBufferTextSource(text, defaultProperties),
                    0, double.PositiveInfinity, paragraphProperties);

-                var expectedRuns = expectedTextLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+                var expectedRuns = expectedTextLine.TextRuns.Cast<ShapedTextRun>().ToList();

                var expectedGlyphs = expectedRuns.SelectMany(x => x.GlyphRun.GlyphIndices).ToList();

@ -539,7 +539,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                        var textLine =
                            formatter.FormatLine(textSource, 0, double.PositiveInfinity, paragraphProperties);

-                        var shapedRuns = textLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+                        var shapedRuns = textLine.TextRuns.Cast<ShapedTextRun>().ToList();

                        var actualGlyphs = shapedRuns.SelectMany(x => x.GlyphRun.GlyphIndices).ToList();

--- a/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextLayoutTests.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextLayoutTests.cs
@ -141,7 +141,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    black,
                    textWrapping: TextWrapping.Wrap);

-                var expectedGlyphs = expected.TextLines.Select(x => string.Join('|', x.TextRuns.Cast<ShapedTextCharacters>()
+                var expectedGlyphs = expected.TextLines.Select(x => string.Join('|', x.TextRuns.Cast<ShapedTextRun>()
                    .SelectMany(x => x.ShapedBuffer.GlyphIndices))).ToList();

                var outer = new GraphemeEnumerator(new CharacterBufferRange(text));
@ -174,7 +174,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                            textWrapping: TextWrapping.Wrap,
                            textStyleOverrides: spans);

-                        var actualGlyphs = actual.TextLines.Select(x => string.Join('|', x.TextRuns.Cast<ShapedTextCharacters>()
+                        var actualGlyphs = actual.TextLines.Select(x => string.Join('|', x.TextRuns.Cast<ShapedTextRun>()
                            .SelectMany(x => x.ShapedBuffer.GlyphIndices))).ToList();

                        Assert.Equal(expectedGlyphs.Count, actualGlyphs.Count);
@ -447,7 +447,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    12.0f,
                    Brushes.Black.ToImmutable());

-                var shapedRun = (ShapedTextCharacters)layout.TextLines[0].TextRuns[0];
+                var shapedRun = (ShapedTextRun)layout.TextLines[0].TextRuns[0];

                var glyphRun = shapedRun.GlyphRun;

@ -481,7 +481,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                foreach (var textRun in textLine.TextRuns)
                {
-                    var shapedRun = (ShapedTextCharacters)textRun;
+                    var shapedRun = (ShapedTextRun)textRun;

                    var glyphClusters = shapedRun.ShapedBuffer.GlyphClusters;

@ -514,13 +514,13 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                Assert.Equal(1, layout.TextLines[0].TextRuns.Count);

-                Assert.Equal(expectedLength, ((ShapedTextCharacters)layout.TextLines[0].TextRuns[0]).GlyphRun.GlyphClusters.Count);
+                Assert.Equal(expectedLength, ((ShapedTextRun)layout.TextLines[0].TextRuns[0]).GlyphRun.GlyphClusters.Count);

-                Assert.Equal(5, ((ShapedTextCharacters)layout.TextLines[0].TextRuns[0]).ShapedBuffer.GlyphClusters[5]);
+                Assert.Equal(5, ((ShapedTextRun)layout.TextLines[0].TextRuns[0]).ShapedBuffer.GlyphClusters[5]);

                if (expectedLength == 7)
                {
-                    Assert.Equal(5, ((ShapedTextCharacters)layout.TextLines[0].TextRuns[0]).ShapedBuffer.GlyphClusters[6]);
+                    Assert.Equal(5, ((ShapedTextRun)layout.TextLines[0].TextRuns[0]).ShapedBuffer.GlyphClusters[6]);
                }
            }
        }
@ -555,7 +555,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                var textLine = layout.TextLines[0];

-                var textRun = (ShapedTextCharacters)textLine.TextRuns[0];
+                var textRun = (ShapedTextRun)textLine.TextRuns[0];

                Assert.Equal(7, textRun.Length);

@ -775,7 +775,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    Assert.Equal(textLine.WidthIncludingTrailingWhitespace, rect.Width);
                }

-                var rects = layout.TextLines.SelectMany(x => x.TextRuns.Cast<ShapedTextCharacters>())
+                var rects = layout.TextLines.SelectMany(x => x.TextRuns.Cast<ShapedTextRun>())
                    .SelectMany(x => x.ShapedBuffer.GlyphAdvances).ToArray();

                for (var i = 0; i < SingleLineText.Length; i++)
@ -814,7 +814,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    {
                        Assert.True(textLine.Width <= maxWidth);

-                        var actual = new string(textLine.TextRuns.Cast<ShapedTextCharacters>()
+                        var actual = new string(textLine.TextRuns.Cast<ShapedTextRun>()
                            .OrderBy(x => x.CharacterBufferReference.OffsetToFirstChar)
                            .SelectMany(x => new CharacterBufferRange(x.CharacterBufferReference, x.Length)).ToArray());

@ -855,7 +855,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    Brushes.Black,
                    flowDirection: FlowDirection.RightToLeft);

-                var firstRun = layout.TextLines[0].TextRuns[0] as ShapedTextCharacters;
+                var firstRun = layout.TextLines[0].TextRuns[0] as ShapedTextRun;

                var hit = layout.HitTestPoint(new Point());

@ -881,7 +881,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    currentX += advance;
                }

-                var secondRun = layout.TextLines[0].TextRuns[1] as ShapedTextCharacters;
+                var secondRun = layout.TextLines[0].TextRuns[1] as ShapedTextRun;

                hit = layout.HitTestPoint(new Point(firstRun.Size.Width, 0));

@ -928,7 +928,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                var textLine = layout.TextLines[0];

-                var firstRun = (ShapedTextCharacters)textLine.TextRuns[0];
+                var firstRun = (ShapedTextRun)textLine.TextRuns[0];

                var firstCluster = firstRun.ShapedBuffer.GlyphClusters[0];

@ -987,7 +987,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                    var textLine = layout.TextLines[0];

-                    var shapedRuns = textLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+                    var shapedRuns = textLine.TextRuns.Cast<ShapedTextRun>().ToList();

                    var clusters = shapedRuns.SelectMany(x => x.ShapedBuffer.GlyphClusters).ToList();

--- a/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextLineTests.cs
+++ b/tests/Avalonia.Skia.UnitTests/Media/TextFormatting/TextLineTests.cs
@ -92,7 +92,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                foreach (var textRun in textLine.TextRuns.OrderBy(x => x.CharacterBufferReference.OffsetToFirstChar))
                {
-                    var shapedRun = (ShapedTextCharacters)textRun;
+                    var shapedRun = (ShapedTextRun)textRun;

                    clusters.AddRange(shapedRun.IsReversed ?
                        shapedRun.ShapedBuffer.GlyphClusters.Reverse() :
@ -139,7 +139,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                foreach (var textRun in textLine.TextRuns.OrderBy(x => x.CharacterBufferReference.OffsetToFirstChar))
                {
-                    var shapedRun = (ShapedTextCharacters)textRun;
+                    var shapedRun = (ShapedTextRun)textRun;

                    clusters.AddRange(shapedRun.IsReversed ?
                        shapedRun.ShapedBuffer.GlyphClusters.Reverse() :
@ -246,7 +246,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    formatter.FormatLine(textSource, 0, double.PositiveInfinity,
                        new GenericTextParagraphProperties(defaultProperties));

-                var clusters = textLine.TextRuns.Cast<ShapedTextCharacters>().SelectMany(x => x.ShapedBuffer.GlyphClusters)
+                var clusters = textLine.TextRuns.Cast<ShapedTextRun>().SelectMany(x => x.ShapedBuffer.GlyphClusters)
                    .ToArray();

                var previousCharacterHit = new CharacterHit(text.Length);
@ -308,7 +308,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                foreach (var run in textLine.TextRuns)
                {
-                    var textRun = (ShapedTextCharacters)run;
+                    var textRun = (ShapedTextRun)run;

                    var glyphRun = textRun.GlyphRun;

@ -634,7 +634,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                    formatter.FormatLine(textSource, 0, double.PositiveInfinity,
                        new GenericTextParagraphProperties(defaultProperties));

-                var textRuns = textLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+                var textRuns = textLine.TextRuns.Cast<ShapedTextRun>().ToList();

                var lineWidth = textLine.WidthIncludingTrailingWhitespace;

@ -732,14 +732,14 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

        private static bool IsRightToLeft(TextLine textLine)
        {
-            return textLine.TextRuns.Cast<ShapedTextCharacters>().Any(x => !x.ShapedBuffer.IsLeftToRight);
+            return textLine.TextRuns.Cast<ShapedTextRun>().Any(x => !x.ShapedBuffer.IsLeftToRight);
        }

        private static List<int> BuildGlyphClusters(TextLine textLine)
        {
            var glyphClusters = new List<int>();

-            var shapedTextRuns = textLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+            var shapedTextRuns = textLine.TextRuns.Cast<ShapedTextRun>().ToList();

            var lastCluster = -1;

@ -774,7 +774,7 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

            var lastCluster = -1;

-            var shapedTextRuns = textLine.TextRuns.Cast<ShapedTextCharacters>().ToList();
+            var shapedTextRuns = textLine.TextRuns.Cast<ShapedTextRun>().ToList();

            foreach (var textRun in shapedTextRuns)
            {
@ -820,16 +820,16 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting
                var text = "0123";
                var shaperOption = new TextShaperOptions(Typeface.Default.GlyphTypeface, 10, 0, CultureInfo.CurrentCulture);

-                var firstRun = new ShapedTextCharacters(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties);
+                var firstRun = new ShapedTextRun(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties);

                var textRuns = new List<TextRun>
                {
                    new CustomDrawableRun(),
                    firstRun,
                    new CustomDrawableRun(),
-                    new ShapedTextCharacters(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties),
+                    new ShapedTextRun(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties),
                    new CustomDrawableRun(),
-                    new ShapedTextCharacters(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties)
+                    new ShapedTextRun(TextShaper.Current.ShapeText(text, shaperOption), defaultProperties)
                };

                var textSource = new FixedRunsTextSource(textRuns);
@ -885,14 +885,14 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                var textBounds = textLine.GetTextBounds(0, 3);

-                var firstRun = textLine.TextRuns[0] as ShapedTextCharacters;
+                var firstRun = textLine.TextRuns[0] as ShapedTextRun;

                Assert.Equal(1, textBounds.Count);
                Assert.Equal(firstRun.Size.Width, textBounds.Sum(x => x.Rectangle.Width));

                textBounds = textLine.GetTextBounds(3, 4);

-                var secondRun = textLine.TextRuns[1] as ShapedTextCharacters;
+                var secondRun = textLine.TextRuns[1] as ShapedTextRun;

                Assert.Equal(1, textBounds.Count);
                Assert.Equal(secondRun.Size.Width, textBounds.Sum(x => x.Rectangle.Width));
@ -932,14 +932,14 @@ namespace Avalonia.Skia.UnitTests.Media.TextFormatting

                var textBounds = textLine.GetTextBounds(0, 4);

-                var secondRun = textLine.TextRuns[1] as ShapedTextCharacters;
+                var secondRun = textLine.TextRuns[1] as ShapedTextRun;

                Assert.Equal(1, textBounds.Count);
                Assert.Equal(secondRun.Size.Width, textBounds.Sum(x => x.Rectangle.Width));

                textBounds = textLine.GetTextBounds(4, 3);

-                var firstRun = textLine.TextRuns[0] as ShapedTextCharacters;
+                var firstRun = textLine.TextRuns[0] as ShapedTextRun;

                Assert.Equal(1, textBounds.Count);

--- a/tests/Avalonia.UnitTests/HarfBuzzFontManagerImpl.cs
+++ b/tests/Avalonia.UnitTests/HarfBuzzFontManagerImpl.cs
@ -76,13 +76,8 @@ namespace Avalonia.UnitTests

            var asset = fontAssets.First();
            
-            var assetLoader = AvaloniaLocator.Current.GetService<IAssetLoader>();
+            var assetLoader = AvaloniaLocator.Current.GetRequiredService<IAssetLoader>();

-            if (assetLoader == null)
-            {
-                throw new NotSupportedException("IAssetLoader is not registered.");
-            }
-            
            var stream = assetLoader.Open(asset);
            
            return new HarfBuzzGlyphTypefaceImpl(stream);