Cleanup and simplify the viewmodels for boolean and enum code styles.

src/VisualStudio/CSharp/Impl/Options/Formatting/StyleViewModel.cs

@@ -715,39 +715,47 @@ private void AddExpressionBodyOptions(OptionSet optionSet, string expressionPref
                 new CodeStylePreference(CSharpVSResources.When_on_single_line, isChecked: false),
             };
 
+            var enumValues = new[] { ExpressionBodyPreference.Never, ExpressionBodyPreference.WhenPossible, ExpressionBodyPreference.WhenOnSingleLine };
+
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedMethods,
                 ServicesVSResources.Use_expression_body_for_methods,
+                enumValues,
                 new[] { s_preferBlockBodyForMethods, s_preferExpressionBodyForMethods, s_preferExpressionBodyForMethods },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
 
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedConstructors,
                 ServicesVSResources.Use_expression_body_for_constructors,
+                enumValues,
                 new[] { s_preferBlockBodyForConstructors, s_preferExpressionBodyForConstructors, s_preferExpressionBodyForConstructors },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
 
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedOperators,
                 ServicesVSResources.Use_expression_body_for_operators,
+                enumValues,
                 new[] { s_preferBlockBodyForOperators, s_preferExpressionBodyForOperators, s_preferExpressionBodyForOperators },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
 
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedProperties,
                 ServicesVSResources.Use_expression_body_for_properties,
+                enumValues,
                 new[] { s_preferBlockBodyForProperties, s_preferExpressionBodyForProperties, s_preferExpressionBodyForProperties },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
 
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedIndexers,
                 ServicesVSResources.Use_expression_body_for_indexers,
+                enumValues,
                 new[] { s_preferBlockBodyForIndexers, s_preferExpressionBodyForIndexers, s_preferExpressionBodyForIndexers },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
 
             CodeStyleItems.Add(new EnumCodeStyleOptionViewModel<ExpressionBodyPreference>(
                 CSharpCodeStyleOptions.PreferExpressionBodiedAccessors,
                 ServicesVSResources.Use_expression_body_for_accessors,
+                enumValues,
                 new[] { s_preferBlockBodyForAccessors, s_preferExpressionBodyForAccessors, s_preferExpressionBodyForAccessors },
                 this, optionSet, expressionPreferencesGroupTitle, expressionBodyPreferences));
         }

src/VisualStudio/Core/Impl/Options/Style/AbstractCodeStyleOptionViewModel.cs

 // Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis.CodeStyle;
 using Microsoft.CodeAnalysis.Options;
@@ -11,8 +10,7 @@
 namespace Microsoft.VisualStudio.LanguageServices.Implementation.Options
 {
     /// <summary>
-    /// This class acts as a base for any view model that 
-    /// binds to the codestyle options UI.
+    /// This class acts as a base for any view model that  binds to the codestyle options UI.
     /// </summary>
     /// <remarks>
     /// This supports databinding of: 
@@ -25,8 +23,6 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.Options
     /// </remarks>
     internal abstract class AbstractCodeStyleOptionViewModel : AbstractNotifyPropertyChanged
     {
-        protected readonly ImmutableArray<string> Previews;
-
         protected AbstractOptionPreviewViewModel Info { get; }
         public IOption Option { get; }
 
@@ -37,7 +33,6 @@ internal abstract class AbstractCodeStyleOptionViewModel : AbstractNotifyPropert
         public List<NotificationOptionViewModel> NotificationPreferences { get; set; }
 
         public abstract CodeStylePreference SelectedPreference { get; set; }
-        public abstract bool NotificationsAvailable { get; }
         public abstract string GetPreview();
 
         public virtual NotificationOptionViewModel SelectedNotificationPreference
@@ -49,15 +44,12 @@ public virtual NotificationOptionViewModel SelectedNotificationPreference
         public AbstractCodeStyleOptionViewModel(
             IOption option,
             string description,
-            string[] previews,
             AbstractOptionPreviewViewModel info,
             OptionSet options,
             string groupName,
             List<CodeStylePreference> preferences = null,
             List<NotificationOptionViewModel> notificationPreferences = null)
         {
-            Previews = ImmutableArray.Create(previews);
-
             Info = info;
             Option = option;
             Description = description;

src/VisualStudio/Core/Impl/Options/Style/BooleanCodeStyleOptionViewModel.cs

@@ -13,40 +13,11 @@ namespace Microsoft.VisualStudio.LanguageServices.Implementation.Options
     /// </summary>
     internal class BooleanCodeStyleOptionViewModel : AbstractCodeStyleOptionViewModel
     {
-        private CodeStylePreference _selectedPreference;
-        public override CodeStylePreference SelectedPreference
-        {
-            get
-            {
-                return _selectedPreference;
-            }
-            set
-            {
-                if (SetProperty(ref _selectedPreference, value))
-                {
-                    Info.SetOptionAndUpdatePreview(new CodeStyleOption<bool>(_selectedPreference.IsChecked, _selectedNotificationPreference.Notification), Option, GetPreview());
-                }
-            }
-        }
+        private readonly string _truePreview;
+        private readonly string _falsePreview;
 
+        private CodeStylePreference _selectedPreference;
         private NotificationOptionViewModel _selectedNotificationPreference;
-        public override NotificationOptionViewModel SelectedNotificationPreference
-        {
-            get
-            {
-                return _selectedNotificationPreference;
-            }
-
-            set
-            {
-                if (SetProperty(ref _selectedNotificationPreference, value))
-                {
-                    Info.SetOptionAndUpdatePreview(new CodeStyleOption<bool>(_selectedPreference.IsChecked, _selectedNotificationPreference.Notification), Option, GetPreview());
-                }
-            }
-        }
-
-        public override bool NotificationsAvailable => true;
 
         public BooleanCodeStyleOptionViewModel(
             IOption option,
@@ -58,8 +29,11 @@ public override NotificationOptionViewModel SelectedNotificationPreference
             string groupName,
             List<CodeStylePreference> preferences = null,
             List<NotificationOptionViewModel> notificationPreferences = null)
-            : base(option, description, new[] { truePreview, falsePreview }, info, options, groupName, preferences, notificationPreferences)
+            : base(option, description, info, options, groupName, preferences, notificationPreferences)
         {
+            _truePreview = truePreview;
+            _falsePreview = falsePreview;
+
             var codeStyleOption = ((CodeStyleOption<bool>)options.GetOption(new OptionKey(option, option.IsPerLanguage ? info.Language : null)));
             _selectedPreference = Preferences.Single(c => c.IsChecked == codeStyleOption.Value);
 
@@ -70,7 +44,33 @@ public override NotificationOptionViewModel SelectedNotificationPreference
             NotifyPropertyChanged(nameof(SelectedNotificationPreference));
         }
 
+        public override CodeStylePreference SelectedPreference
+        {
+            get => _selectedPreference;
+
+            set
+            {
+                if (SetProperty(ref _selectedPreference, value))
+                {
+                    Info.SetOptionAndUpdatePreview(new CodeStyleOption<bool>(_selectedPreference.IsChecked, _selectedNotificationPreference.Notification), Option, GetPreview());
+                }
+            }
+        }
+
+        public override NotificationOptionViewModel SelectedNotificationPreference
+        {
+            get => _selectedNotificationPreference;
+
+            set
+            {
+                if (SetProperty(ref _selectedNotificationPreference, value))
+                {
+                    Info.SetOptionAndUpdatePreview(new CodeStyleOption<bool>(_selectedPreference.IsChecked, _selectedNotificationPreference.Notification), Option, GetPreview());
+                }
+            }
+        }
+
         public override string GetPreview() 
-            => SelectedPreference.IsChecked ? Previews[0] : Previews[1];
+            => SelectedPreference.IsChecked ? _truePreview : _falsePreview;
     }
 }
\ No newline at end of file

src/VisualStudio/Core/Impl/Options/Style/EnumCodeStyleOptionViewModel.cs

@@ -27,23 +27,60 @@ static EnumCodeStyleOptionViewModel()
             Contract.ThrowIfFalse(typeof(T).IsEnum);
         }
 
-        private static readonly ImmutableArray<T> s_enumValues =
-            ImmutableArray.Create((T[])Enum.GetValues(typeof(T)));
+        private readonly ImmutableArray<T> _enumValues;
+        private readonly ImmutableArray<string> _previews;
 
         private CodeStylePreference _selectedPreference;
+        private NotificationOptionViewModel _selectedNotificationPreference;
+
+        public EnumCodeStyleOptionViewModel(
+            Option<CodeStyleOption<T>> option,
+            string description,
+            T[] enumValues,
+            string[] previews,
+            AbstractOptionPreviewViewModel info,
+            OptionSet options,
+            string groupName,
+            List<CodeStylePreference> preferences)
+            : base(option, description, info, options, groupName, preferences)
+        {
+            Debug.Assert(preferences.Count == enumValues.Length);
+            Debug.Assert(previews.Length == enumValues.Length);
+
+            var expectedEnumValues = Enum.GetValues(typeof(T));
+            Debug.Assert(expectedEnumValues.Length == enumValues.Length, "Enum was updated, but UI wasn't.");
+
+            _enumValues = enumValues.ToImmutableArray();
+            _previews = previews.ToImmutableArray();
+
+            var codeStyleOption = options.GetOption(option);
+
+            var enumIndex = _enumValues.IndexOf(codeStyleOption.Value);
+            _selectedPreference = Preferences[enumIndex];
+
+            var notificationViewModel = NotificationPreferences.Single(i => i.Notification.Value == codeStyleOption.Notification.Value);
+            _selectedNotificationPreference = NotificationPreferences.Single(p => p.Notification.Value == notificationViewModel.Notification.Value);
+
+            NotifyPropertyChanged(nameof(SelectedPreference));
+            NotifyPropertyChanged(nameof(SelectedNotificationPreference));
+        }
+
+        public override string GetPreview()
+        {
+            var index = Preferences.IndexOf(SelectedPreference);
+            return _previews[index];
+        }
+
         public override CodeStylePreference SelectedPreference
         {
-            get
-            {
-                return _selectedPreference;
-            }
+            get => _selectedPreference;
 
             set
             {
                 if (SetProperty(ref _selectedPreference, value))
                 {
                     var index = Preferences.IndexOf(value);
-                    var enumValue = s_enumValues[index];
+                    var enumValue = _enumValues[index];
 
                     Info.SetOptionAndUpdatePreview(
                         new CodeStyleOption<T>(
@@ -53,20 +90,16 @@ public override CodeStylePreference SelectedPreference
             }
         }
 
-        private NotificationOptionViewModel _selectedNotificationPreference;
         public override NotificationOptionViewModel SelectedNotificationPreference
         {
-            get
-            {
-                return _selectedNotificationPreference;
-            }
+            get => _selectedNotificationPreference;
 
             set
             {
                 if (SetProperty(ref _selectedNotificationPreference, value))
                 {
                     var index = Preferences.IndexOf(SelectedPreference);
-                    var enumValue = s_enumValues[index];
+                    var enumValue = _enumValues[index];
 
                     Info.SetOptionAndUpdatePreview(
                         new CodeStyleOption<T>(
@@ -75,38 +108,5 @@ public override NotificationOptionViewModel SelectedNotificationPreference
                 }
             }
         }
-
-        public override bool NotificationsAvailable => true;
-
-        public override string GetPreview()
-        {
-            var index = Preferences.IndexOf(SelectedPreference);
-            return Previews[index];
-        }
-
-        public EnumCodeStyleOptionViewModel(
-            Option<CodeStyleOption<T>> option,
-            string description,
-            string[] previews,
-            AbstractOptionPreviewViewModel info,
-            OptionSet options,
-            string groupName,
-            List<CodeStylePreference> preferences)
-            : base(option, description, previews, info, options, groupName, preferences)
-        {
-            Debug.Assert(preferences.Count == s_enumValues.Length);
-            Debug.Assert(previews.Length == s_enumValues.Length);
-
-            var codeStyleOption = options.GetOption(option);
-
-            var enumIndex = s_enumValues.IndexOf(codeStyleOption.Value);
-            _selectedPreference = Preferences[enumIndex];
-
-            var notificationViewModel = NotificationPreferences.Single(i => i.Notification.Value == codeStyleOption.Notification.Value);
-            _selectedNotificationPreference = NotificationPreferences.Single(p => p.Notification.Value == notificationViewModel.Notification.Value);
-
-            NotifyPropertyChanged(nameof(SelectedPreference));
-            NotifyPropertyChanged(nameof(SelectedNotificationPreference));
-        }
     }
 }
\ No newline at end of file