Merge pull request #70 from meziantou/issue69

Add support for min-content, max-content and fit-content

Author: FlorianRappl

src/AngleSharp.Css.Tests/Declarations/CssWidthProperty.cs

@@ -0,0 +1,45 @@
+namespace AngleSharp.Css.Tests.Declarations
+{
+    using NUnit.Framework;
+    using static CssConstructionFunctions;
+
+    [TestFixture]
+    public class CssWidthPropertyTests
+    {
+        [Test]
+        public void CssWidthPropertyAutoLegal()
+        {
+            var snippet = "width: auto";
+            var property = ParseDeclaration(snippet);
+            Assert.AreEqual("width", property.Name);
+            Assert.IsFalse(property.IsImportant);
+            Assert.IsFalse(property.IsInherited);
+            Assert.IsTrue(property.HasValue);
+            Assert.AreEqual("auto", property.Value);
+        }
+        
+        [Test]
+        public void CssWidthPropertyFitContentLegal()
+        {
+            var snippet = "width: fit-content";
+            var property = ParseDeclaration(snippet);
+            Assert.AreEqual("width", property.Name);
+            Assert.IsFalse(property.IsImportant);
+            Assert.IsFalse(property.IsInherited);
+            Assert.IsTrue(property.HasValue);
+            Assert.AreEqual("fit-content", property.Value);
+        }
+
+        [Test]
+        public void CssWidthPropertyValueInPxLegal()
+        {
+            var snippet = "width: 42px";
+            var property = ParseDeclaration(snippet);
+            Assert.AreEqual("width", property.Name);
+            Assert.IsFalse(property.IsImportant);
+            Assert.IsFalse(property.IsInherited);
+            Assert.IsTrue(property.HasValue);
+            Assert.AreEqual("42px", property.Value);
+        }
+    }
+}

src/AngleSharp.Css/Constants/CssKeywords.cs

@@ -1566,5 +1566,10 @@ public static class CssKeywords
         /// The closed keyword.
         /// </summary>
         public static readonly String Closed = "closed";
+
+        /// <summary>
+        /// The fit-content keyword.
+        /// </summary>
+        public static readonly String FitContent = "fit-content";
     }
 }

src/AngleSharp.Css/Constants/Map.cs

@@ -883,5 +883,15 @@ static class Map
             { CssKeywords.Compact, FootnoteDisplay.Compact },
             { CssKeywords.Inline, FootnoteDisplay.Inline },
         };
+
+        /// <summary>
+        /// Contains the string-length mapping.
+        /// </summary>
+        public static readonly Dictionary<String, Sizing> Sizings = new Dictionary<String, Width>(StringComparer.OrdinalIgnoreCase)
+        {
+            { CssKeywords.FitContent, Sizing.FitContent },
+            { CssKeywords.MinContent, Sizing.MinContent},
+            { CssKeywords.MaxContent, Sizing.MaxContent },
+        };
     }
 }

src/AngleSharp.Css/Declarations/WidthDeclaration.cs

@@ -8,7 +8,7 @@ static class WidthDeclaration
     {
         public static String Name = PropertyNames.Width;
 
-        public static IValueConverter Converter = AutoLengthOrPercentConverter;
+        public static IValueConverter Converter = WidthConverter;
 
         public static ICssValue InitialValue = InitialValues.WidthDecl;
 

src/AngleSharp.Css/Dom/Sizing.cs

@@ -0,0 +1,22 @@
+namespace AngleSharp.Css.Dom
+{
+    /// <summary>
+    /// Represents the selected Width display mode.
+    /// </summary>
+    public enum Sizing
+    {
+        /// <summary>
+        /// Essentially fit-content(stretch) i.e. min(max-content, max(min-content, stretch)).
+        /// <seealso href="https://drafts.csswg.org/css-sizing-4/#valdef-width-fit-content"/>
+        /// </summary>
+        FitContent,
+        /// <summary>
+        /// The intrinsic preferred width.
+        /// </summary>
+        MaxContent,
+        /// <summary>
+        /// The intrinsic minimum width.
+        /// </summary>
+        MinContent,
+    }
+}

src/AngleSharp.Css/ValueConverters.cs

@@ -612,6 +612,14 @@ static class ValueConverters
         public static readonly IValueConverter AutoLengthOrPercentConverter = Or(
             LengthOrPercentConverter,
             Auto);
+        
+        /// <summary>
+        /// Represents a value for a width.
+        /// </summary>
+        public static readonly IValueConverter WidthConverter = Or(
+            LengthOrPercentConverter,
+            Auto,
+            Map.Sizings.ToConverter());
 
         /// <summary>
         /// Represents a length for a font size.