Minor code refactoring

Source/QuestPDF.Examples/TextExamples.cs

@@ -1004,5 +1004,40 @@ namespace QuestPDF.Examples
                         });
                 });
         }
+        
+        [Test]
+         public void FontFallback_Nested()
+        {
+            RenderingTest
+                .Create()
+                .ProduceImages()
+                .ShowResults()
+                .RenderDocument(container =>
+                {
+                    container.Page(page =>
+                    {
+                        page.Margin(50);
+                        page.PageColor(Colors.White);
+                        page.Size(PageSizes.A5.Landscape());
+                        
+                        page.DefaultTextStyle(x => x
+                            .FontSize(24)
+                            .Bold()
+                            .FontFamily("Times New Roman")
+                            .Fallback(y => y
+                                .FontFamily("Microsoft YaHei")
+                                .Underline()
+                                .BackgroundColor(Colors.Red.Lighten2)));
+
+                        page.Content().Text(text =>
+                        {
+                            text.Line("Default times new roman 中文文本 text.");
+                            text.Line("Normal weight and green 中文文本 text.").NormalWeight().BackgroundColor(Colors.Green.Lighten2);
+                            text.Line("Strikethrough without underline 中文文本 text.").Strikethrough().Underline(false);
+                            text.Line("Lato italic 中文文本 text.").FontFamily("Lato").Italic();
+                        });
+                    });
+                });
+        }
     }
 }

Source/QuestPDF.UnitTests/QuestPDF.UnitTests.csproj

@@ -3,6 +3,7 @@
     <PropertyGroup>
         <TargetFramework>netcoreapp3.1</TargetFramework>
         <IsPackable>false</IsPackable>
+        <LangVersion>9</LangVersion>
     </PropertyGroup>
 
     <ItemGroup>

Source/QuestPDF.UnitTests/TextStyleTests.cs

@@ -0,0 +1,59 @@
+using FluentAssertions;
+using NUnit.Framework;
+using QuestPDF.Fluent;
+using QuestPDF.Helpers;
+using QuestPDF.Infrastructure;
+
+namespace QuestPDF.UnitTests
+{
+    [TestFixture]
+    public class TextStyleTests
+    {
+        [Test]
+        public void ApplyInheritedAndGlobalStyle()
+        {
+            // arrange
+            var defaultTextStyle = TextStyle
+                .Default
+                .FontSize(20)
+                .FontFamily("Arial")
+                .BackgroundColor(Colors.Green.Lighten2)
+                .Fallback(y => y
+                    .FontFamily("Microsoft YaHei")
+                    .Underline()
+                    .NormalWeight()
+                    .BackgroundColor(Colors.Blue.Lighten2));
+
+            var spanTextStyle = TextStyle
+                .Default
+                .FontFamily("Times New Roman")
+                .Bold()
+                .Strikethrough()
+                .BackgroundColor(Colors.Red.Lighten2);
+            
+            // act
+            var targetStyle = spanTextStyle.ApplyInheritedStyle(defaultTextStyle).ApplyGlobalStyle();
+            
+            // assert
+            var expectedStyle = TextStyle.LibraryDefault with
+            {
+                Size = 20, 
+                FontFamily = "Times New Roman",
+                FontWeight = FontWeight.Bold,
+                BackgroundColor = Colors.Red.Lighten2,
+                HasStrikethrough = true,
+                Fallback = TextStyle.LibraryDefault with
+                {
+                    Size = 20,
+                    FontFamily = "Microsoft YaHei",
+                    FontWeight = FontWeight.Bold,
+                    BackgroundColor = Colors.Red.Lighten2,
+                    HasUnderline = true,
+                    HasStrikethrough = true
+                }
+            };
+
+            targetStyle.Should().BeEquivalentTo(expectedStyle);
+        }
+    }
+}

Source/QuestPDF/Drawing/DocumentGenerator.cs

@@ -64,7 +64,7 @@ namespace QuestPDF.Drawing
             var container = new DocumentContainer();
             document.Compose(container);
             var content = container.Compose();
-            ApplyDefaultTextStyle(content, TextStyle.LibraryDefault);
+            ApplyInheritedAndGlobalTexStyle(content, TextStyle.Default);
             ApplyContentDirection(content, ContentDirection.LeftToRight);
             
             var debuggingState = Settings.EnableDebugging ? ApplyDebugging(content) : null;
@@ -192,7 +192,7 @@ namespace QuestPDF.Drawing
                 ApplyContentDirection(child, direction);
         }
 
-        internal static void ApplyDefaultTextStyle(this Element? content, TextStyle documentDefaultTextStyle)
+        internal static void ApplyInheritedAndGlobalTexStyle(this Element? content, TextStyle documentDefaultTextStyle)
         {
             if (content == null)
                 return;
@@ -202,26 +202,23 @@ namespace QuestPDF.Drawing
                 foreach (var textBlockItem in textBlock.Items)
                 {
                     if (textBlockItem is TextBlockSpan textSpan)
-                    {
+                        textSpan.Style = textSpan.Style.ApplyInheritedStyle(documentDefaultTextStyle).ApplyGlobalStyle();
-                        textSpan.Style = textSpan.Style.ApplyGlobalStyle(documentDefaultTextStyle);
+                    
-                    }
+                    if (textBlockItem is TextBlockElement textElement)
-                    else if (textBlockItem is TextBlockElement textElement)
+                        ApplyInheritedAndGlobalTexStyle(textElement.Element, documentDefaultTextStyle);
-                    {
-                        ApplyDefaultTextStyle(textElement.Element, documentDefaultTextStyle);
-                    }
                 }
                 
                 return;
             }
 
             if (content is DynamicHost dynamicHost)
-                dynamicHost.TextStyle = dynamicHost.TextStyle.ApplyGlobalStyle(documentDefaultTextStyle);
+                dynamicHost.TextStyle = dynamicHost.TextStyle.ApplyInheritedStyle(documentDefaultTextStyle);
             
             if (content is DefaultTextStyle defaultTextStyleElement)
-               documentDefaultTextStyle = defaultTextStyleElement.TextStyle.ApplyGlobalStyle(documentDefaultTextStyle);
+               documentDefaultTextStyle = defaultTextStyleElement.TextStyle.ApplyInheritedStyle(documentDefaultTextStyle);
 
             foreach (var child in content.GetChildren())
-                ApplyDefaultTextStyle(child, documentDefaultTextStyle);
+                ApplyInheritedAndGlobalTexStyle(child, documentDefaultTextStyle);
         }
     }
 }

Source/QuestPDF/Elements/Dynamic.cs

@@ -89,7 +89,7 @@ namespace QuestPDF.Elements
             var container = new DynamicElement();
             content(container);
             
-            container.ApplyDefaultTextStyle(TextStyle);
+            container.ApplyInheritedAndGlobalTexStyle(TextStyle);
             container.ApplyContentDirection(ContentDirection);
             
             container.InjectDependencies(PageContext, Canvas);

Source/QuestPDF/Infrastructure/TextStyleManager.cs

@@ -25,16 +25,17 @@ namespace QuestPDF.Infrastructure
     internal static class TextStyleManager
     {
         private static readonly ConcurrentDictionary<(TextStyle origin, TextStyleProperty property, object value), TextStyle> TextStyleMutateCache = new();
-        private static readonly ConcurrentDictionary<(TextStyle origin, TextStyle parent), TextStyle> TextStyleApplyGlobalCache = new();
+        private static readonly ConcurrentDictionary<(TextStyle origin, TextStyle parent), TextStyle> TextStyleApplyInheritedCache = new();
+        private static readonly ConcurrentDictionary<TextStyle, TextStyle> TextStyleApplyGlobalCache = new();
         private static readonly ConcurrentDictionary<(TextStyle origin, TextStyle parent), TextStyle> TextStyleOverrideCache = new();
 
         public static TextStyle Mutate(this TextStyle origin, TextStyleProperty property, object value)
         {
             var cacheKey = (origin, property, value);
-            return TextStyleMutateCache.GetOrAdd(cacheKey, x => MutateStyle(x.origin, x.property, x.value));
+            return TextStyleMutateCache.GetOrAdd(cacheKey, x => MutateStyle(x.origin, x.property, x.value, overrideValue: true));
         }
 
-        private static TextStyle MutateStyle(TextStyle origin, TextStyleProperty property, object? value, bool overrideValue = true)
+        private static TextStyle MutateStyle(this TextStyle origin, TextStyleProperty property, object? value, bool overrideValue)
         {
             if (overrideValue && value == null)
                 return origin;
@@ -224,37 +225,37 @@ namespace QuestPDF.Infrastructure
             throw new ArgumentOutOfRangeException(nameof(property), property, "Expected to mutate the TextStyle object. Provided property type is not supported.");
         }
         
-        internal static TextStyle ApplyGlobalStyle(this TextStyle style, TextStyle parent)
+        internal static TextStyle ApplyInheritedStyle(this TextStyle style, TextStyle parent)
         {
             var cacheKey = (style, parent);
-            return TextStyleApplyGlobalCache.GetOrAdd(cacheKey, key => ApplyStyle(key.origin, key.parent, overrideStyle: false).ApplyFontFallback());
+            return TextStyleApplyInheritedCache.GetOrAdd(cacheKey, key => key.origin.ApplyStyleProperties(key.parent, overrideStyle: false, overrideFontFamily: false, applyFallback: true).UpdateFontFallback(overrideStyle: true));
         }
         
-        private static TextStyle ApplyFontFallback(this TextStyle style)
+        internal static TextStyle ApplyGlobalStyle(this TextStyle style)
+        {
+            return TextStyleApplyGlobalCache.GetOrAdd(style, key => key.ApplyStyleProperties(TextStyle.LibraryDefault, overrideStyle: false, overrideFontFamily: false, applyFallback: true).UpdateFontFallback(overrideStyle: false));
+        }
+        
+        private static TextStyle UpdateFontFallback(this TextStyle style, bool overrideStyle)
         {
             var targetFallbackStyle = style
                 ?.Fallback
-                ?.ApplyStyle(style, overrideStyle: false, applyFallback: false)
+                ?.ApplyStyleProperties(style, overrideStyle: overrideStyle, overrideFontFamily: false, applyFallback: false)
-                ?.ApplyFontFallback();
+                ?.UpdateFontFallback(overrideStyle);
             
-            return MutateStyle(style, TextStyleProperty.Fallback, targetFallbackStyle);
+            return style.MutateStyle(TextStyleProperty.Fallback, targetFallbackStyle, overrideValue: true);
         }
         
         internal static TextStyle OverrideStyle(this TextStyle style, TextStyle parent)
         {
             var cacheKey = (style, parent);
-            
+            return TextStyleOverrideCache.GetOrAdd(cacheKey, key => ApplyStyleProperties(key.origin, key.parent, overrideStyle: true, overrideFontFamily: true, applyFallback: true));
-            return TextStyleOverrideCache.GetOrAdd(cacheKey, key =>
-            {
-                var result = ApplyStyle(key.origin, key.parent);
-                return MutateStyle(result, TextStyleProperty.Fallback, key.parent.Fallback);
-            });
         }
         
-        private static TextStyle ApplyStyle(this TextStyle style, TextStyle parent, bool overrideStyle = true, bool applyFallback = true)
+        private static TextStyle ApplyStyleProperties(this TextStyle style, TextStyle parent, bool overrideStyle, bool overrideFontFamily, bool applyFallback)
         {
             var result = style;
-
+            
             result = MutateStyle(result, TextStyleProperty.Color, parent.Color, overrideStyle);
             result = MutateStyle(result, TextStyleProperty.BackgroundColor, parent.BackgroundColor, overrideStyle);
             result = MutateStyle(result, TextStyleProperty.FontFamily, parent.FontFamily, overrideStyle);