From 127133eb89d2a14380a26475bad9f9c049836203 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Wed, 17 Feb 2016 18:59:27 +0100
Subject: [PATCH] Added enum conversions to DefaultValueConverter.

---
 .../Perspex.Markup/DefaultValueConverter.cs   | 35 ++++++++++++++-
 src/Perspex.Base/Utilities/TypeUtilities.cs   | 10 +++--
 .../DefaultValueConverterTests.cs             | 43 +++++++++++++++++--
 3 files changed, 81 insertions(+), 7 deletions(-)

diff --git a/src/Markup/Perspex.Markup/DefaultValueConverter.cs b/src/Markup/Perspex.Markup/DefaultValueConverter.cs
index e49c1c3ae6..23bb0f774c 100644
--- a/src/Markup/Perspex.Markup/DefaultValueConverter.cs
+++ b/src/Markup/Perspex.Markup/DefaultValueConverter.cs
@@ -3,6 +3,8 @@
 
 using System;
 using System.Globalization;
+using System.Linq;
+using System.Reflection;
 using Perspex.Utilities;
 
 namespace Perspex.Markup
@@ -30,7 +32,9 @@ namespace Perspex.Markup
         {
             object result;
 
-            if (value != null && TypeUtilities.TryConvert(targetType, value, culture, out result))
+            if (value != null && 
+                (TypeUtilities.TryConvert(targetType, value, culture, out result) ||
+                 TryConvertEnum(value, targetType, culture, out result)))
             {
                 return result;
             }
@@ -52,5 +56,34 @@ namespace Perspex.Markup
         {
             return Convert(value, targetType, parameter, culture);
         }
+
+        private bool TryConvertEnum(object value, Type targetType, CultureInfo cultur, out object result)
+        {
+            var valueTypeInfo = value.GetType().GetTypeInfo();
+            var targetTypeInfo = targetType.GetTypeInfo();
+
+            if (valueTypeInfo.IsEnum && !targetTypeInfo.IsEnum)
+            {
+                var enumValue = (int)value;
+
+                if (TypeUtilities.TryCast(targetType, enumValue, out result))
+                {
+                    return true;
+                }
+            }
+            else if (!valueTypeInfo.IsEnum && targetTypeInfo.IsEnum)
+            {
+                object intValue;
+
+                if (TypeUtilities.TryCast(typeof(int), value, out intValue))
+                {
+                    result = Enum.ToObject(targetType, intValue);
+                    return true;
+                }
+            }
+
+            result = null;
+            return false;
+        }
     }
 }
diff --git a/src/Perspex.Base/Utilities/TypeUtilities.cs b/src/Perspex.Base/Utilities/TypeUtilities.cs
index 3d19de5f97..c6d16d56b2 100644
--- a/src/Perspex.Base/Utilities/TypeUtilities.cs
+++ b/src/Perspex.Base/Utilities/TypeUtilities.cs
@@ -119,6 +119,12 @@ namespace Perspex.Utilities
                 return true;
             }
 
+            if (to == typeof(string))
+            {
+                result = Convert.ToString(value);
+                return true;
+            }
+
             if (to.GetTypeInfo().IsEnum && from == typeof(string))
             {
                 if (Enum.IsDefined(to, (string)value))
@@ -131,9 +137,7 @@ namespace Perspex.Utilities
             bool containsFrom = Conversions.ContainsKey(from);
             bool containsTo = Conversions.ContainsKey(to);
 
-            if ((containsFrom && containsTo) ||
-                (from == typeof(string) && containsTo) ||
-                (to == typeof(string) && containsFrom))
+            if ((containsFrom && containsTo) || (from == typeof(string) && containsTo))
             {
                 try
                 {
diff --git a/tests/Perspex.Markup.UnitTests/DefaultValueConverterTests.cs b/tests/Perspex.Markup.UnitTests/DefaultValueConverterTests.cs
index b438d6af1d..55034a3c53 100644
--- a/tests/Perspex.Markup.UnitTests/DefaultValueConverterTests.cs
+++ b/tests/Perspex.Markup.UnitTests/DefaultValueConverterTests.cs
@@ -2,6 +2,7 @@
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
 using System.Globalization;
+using Perspex.Controls;
 using Xunit;
 
 namespace Perspex.Markup.UnitTests
@@ -44,6 +45,18 @@ namespace Perspex.Markup.UnitTests
             Assert.Equal(TestEnum.Bar, result);
         }
 
+        [Fact]
+        public void Can_Convert_Int_To_Enum()
+        {
+            var result = DefaultValueConverter.Instance.Convert(
+                1,
+                typeof(TestEnum),
+                null,
+                CultureInfo.InvariantCulture);
+
+            Assert.Equal(TestEnum.Bar, result);
+        }
+
         [Fact]
         public void Can_Convert_Double_To_String()
         {
@@ -57,15 +70,27 @@ namespace Perspex.Markup.UnitTests
         }
 
         [Fact]
-        public void Can_Convert_Double_To_Int()
+        public void Can_Convert_Enum_To_Int()
         {
             var result = DefaultValueConverter.Instance.Convert(
-                5.0,
+                TestEnum.Bar,
                 typeof(int),
                 null,
                 CultureInfo.InvariantCulture);
 
-            Assert.Equal(5, result);
+            Assert.Equal(1, result);
+        }
+
+        [Fact]
+        public void Can_Convert_Enum_To_String()
+        {
+            var result = DefaultValueConverter.Instance.Convert(
+                TestEnum.Bar,
+                typeof(string),
+                null,
+                CultureInfo.InvariantCulture);
+
+            Assert.Equal("Bar", result);
         }
 
         [Fact]
@@ -80,6 +105,18 @@ namespace Perspex.Markup.UnitTests
             Assert.Equal(5.0, result);
         }
 
+        [Fact]
+        public void Cannot_Convert_Between_Different_Enum_Types()
+        {
+            var result = DefaultValueConverter.Instance.Convert(
+                TestEnum.Foo,
+                typeof(Orientation),
+                null,
+                CultureInfo.InvariantCulture);
+
+            Assert.Equal(PerspexProperty.UnsetValue, result);
+        }
+
         private enum TestEnum
         {
             Foo,