Merge pull request #7 from SamirKharchi/Improve-Enum-Display-By-Using…

…-Description

Enum type editor now uses and favors existing enum entry descriptions.

src/Shared/HandyControl_Shared/Controls/PropertyGrid/Editors/EnumPropertyEditor.cs

@@ -1,17 +1,66 @@
 using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Globalization;
+using System.Linq;
 using System.Windows;
 using System.Windows.Controls.Primitives;
+using System.Windows.Data;
 
 namespace HandyControl.Controls
 {
     public class EnumPropertyEditor : PropertyEditorBase
     {
-        public override FrameworkElement CreateElement(PropertyItem propertyItem) => new System.Windows.Controls.ComboBox
-        {
-            IsEnabled = !propertyItem.IsReadOnly,
-            ItemsSource = Enum.GetValues(propertyItem.PropertyType)
-        };
+        public override FrameworkElement CreateElement(PropertyItem propertyItem) =>
+            new System.Windows.Controls.ComboBox
+            {
+                IsEnabled   = !propertyItem.IsReadOnly,
+                ItemsSource = EnumPropertyEditor.GetEnumDescription(propertyItem.PropertyType)
+            };
 
         public override DependencyProperty GetDependencyProperty() => Selector.SelectedValueProperty;
+
+        protected override IValueConverter GetConverter(PropertyItem propertyItem) => new EnumDescriptionConverter(propertyItem.PropertyType);
+
+        private static IEnumerable<string> GetEnumDescription(Type enumType)
+        {
+            var values    = Enum.GetValues(enumType);
+            var enumDescs = new List<string>(values.Length);
+
+            enumDescs.AddRange(from object value in values
+                               select enumType.GetField(value.ToString())
+                               into field
+                               let attributes = field.GetCustomAttributes(typeof(DescriptionAttribute), false)
+                               select (attributes.Length == 0 ? field.Name : ((DescriptionAttribute) attributes[0]).Description));
+
+            return enumDescs;
+        }
+
+        private class EnumDescriptionConverter : IValueConverter
+        {
+            private readonly List<KeyValuePair<Enum, string>> cache;
+
+            public EnumDescriptionConverter(Type enumType)
+            {
+                var values = Enum.GetValues(enumType);
+
+                cache = new List<KeyValuePair<Enum, string>>(values.Length);
+
+                foreach (var value in values)
+                {
+                    var field      = enumType.GetField(value.ToString());
+                    var attributes = field.GetCustomAttributes(typeof(DescriptionAttribute), false);
+                    var fieldValue = (attributes.Length == 0 ? field.Name : ((DescriptionAttribute) attributes[0]).Description);
+
+                    cache.Add(new KeyValuePair<Enum, string>((Enum) value, fieldValue));
+                }
+            }
+
+            object IValueConverter.Convert(object value, Type targetType, object parameter, CultureInfo culture) =>
+                cache.First(x => x.Key.Equals((Enum) value)).Value;
+
+            object IValueConverter.ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) =>
+                cache.First(x => x.Value == (string) value).Key;
+        }
     }
 }