Move Thickness parsing to Thickness.Parse.

And added unit tests.

Tests/Perspex.SceneGraph.UnitTests/ThicknessTests.cs

@@ -0,0 +1,45 @@
+// -----------------------------------------------------------------------
+// <copyright file="ThicknessTests.cs" company="Steven Kirk">
+// Copyright 2015 MIT Licence. See licence.md for more information.
+// </copyright>
+// -----------------------------------------------------------------------
+
+namespace Perspex.SceneGraph.UnitTests.Media
+{
+    using Xunit;
+
+    public class ThicknessTests
+    {
+        [Fact]
+        public void Parse_Parses_Single_Uniform_Size()
+        {
+            var result = Thickness.Parse("1.2");
+
+            Assert.Equal(new Thickness(1.2), result);
+        }
+
+        [Fact]
+        public void Parse_Parses_Horizontal_Vertical()
+        {
+            var result = Thickness.Parse("1.2,3.4");
+
+            Assert.Equal(new Thickness(1.2, 3.4), result);
+        }
+
+        [Fact]
+        public void Parse_Parses_Left_Top_Right_Bottom()
+        {
+            var result = Thickness.Parse("1.2, 3.4, 5, 6");
+
+            Assert.Equal(new Thickness(1.2, 3.4, 5, 6), result);
+        }
+
+        [Fact]
+        public void Parse_Accepts_Spaces()
+        {
+            var result = Thickness.Parse("1.2 3.4 5 6");
+
+            Assert.Equal(new Thickness(1.2, 3.4, 5, 6), result);
+        }
+    }
+}

src/Markup/Perspex.Markup.Xaml/Converters/ThicknessConverter.cs

@@ -7,66 +7,29 @@
 namespace Perspex.Markup.Xaml.Converters
 {
     using System;
-    using System.Collections.Generic;
     using System.Globalization;
-    using System.Linq;
     using OmniXaml.TypeConversion;
 
     public class ThicknessConverter : ITypeConverter
     {
-        public object ConvertFrom(IXamlTypeConverterContext context, CultureInfo culture, object value)
+        public bool CanConvertFrom(IXamlTypeConverterContext context, Type sourceType)
         {
-            var s = value as string;
-            if (s != null)
-            {
-                return ConvertFromString(s);
-            }
-
-            return null;
+            return sourceType == typeof(string);
         }
 
-        private static Thickness ConvertFromString(string s)
+        public bool CanConvertTo(IXamlTypeConverterContext context, Type destinationType)
         {
-            var parts = s.Split(',', ' ');
-
-            switch (parts.Length)
-            {
-                case 1:
-                    var uniform = double.Parse(parts[0]);
-                    return new Thickness(uniform);
-                case 2:
-                    var horizontal = double.Parse(parts[0]);
-                    var vertical = double.Parse(parts[1]);
-                    return new Thickness(horizontal, vertical);
-                case 4:
-                    var left = double.Parse(parts[0]);
-                    var top = double.Parse(parts[1]);
-                    var right = double.Parse(parts[2]);
-                    var bottom = double.Parse(parts[3]);
-                    return new Thickness(left, top, right, bottom);
-            }
-
-            throw new InvalidOperationException("Invalid Thickness.");
+            return false;
         }
 
-        public object ConvertTo(IXamlTypeConverterContext context, CultureInfo culture, object value, Type destinationType)
+        public object ConvertFrom(IXamlTypeConverterContext context, CultureInfo culture, object value)
         {
-            throw new System.NotImplementedException();
+            return Thickness.Parse((string)value);
         }
 
-        public bool CanConvertTo(IXamlTypeConverterContext context, Type destinationType)
+        public object ConvertTo(IXamlTypeConverterContext context, CultureInfo culture, object value, Type destinationType)
         {
             throw new NotImplementedException();
         }
-
-        public bool CanConvertFrom(IXamlTypeConverterContext context, Type sourceType)
-        {
-            if (sourceType == typeof(string))
-            {
-                return true;
-            }
-
-            return false;
-        }
     }
 }

src/Perspex.SceneGraph/Thickness.cs

@@ -7,6 +7,7 @@
 namespace Perspex
 {
     using System;
+    using System.Linq;
 
     /// <summary>
     /// Describes the thickness of a frame around a rectangle.
@@ -155,6 +156,37 @@ namespace Perspex
                 a.Bottom + b.Bottom);
         }
 
+        /// <summary>
+        /// Parses a <see cref="Thickness"/> string.
+        /// </summary>
+        /// <param name="s">The string.</param>
+        /// <returns>The <see cref="Thickness"/>.</returns>
+        public static Thickness Parse(string s)
+        {
+            var parts = s.Split(new[] { ',', ' ' }, StringSplitOptions.RemoveEmptyEntries)
+                .Select(x => x.Trim())
+                .ToList();
+
+            switch (parts.Count)
+            {
+                case 1:
+                    var uniform = double.Parse(parts[0]);
+                    return new Thickness(uniform);
+                case 2:
+                    var horizontal = double.Parse(parts[0]);
+                    var vertical = double.Parse(parts[1]);
+                    return new Thickness(horizontal, vertical);
+                case 4:
+                    var left = double.Parse(parts[0]);
+                    var top = double.Parse(parts[1]);
+                    var right = double.Parse(parts[2]);
+                    var bottom = double.Parse(parts[3]);
+                    return new Thickness(left, top, right, bottom);
+            }
+
+            throw new FormatException("Invalid Thickness.");
+        }
+
         /// <summary>
         /// Checks for equality between a thickness and an object.
         /// </summary>

tests/Perspex.SceneGraph.UnitTests/Perspex.SceneGraph.UnitTests.csproj

@@ -80,6 +80,7 @@
     <Otherwise />
   </Choose>
   <ItemGroup>
+    <Compile Include="ThicknessTests.cs" />
     <Compile Include="GlobalSuppressions.cs" />
     <Compile Include="Media\BrushTests.cs" />
     <Compile Include="Media\ColorTests.cs" />