Starting to add an edit command

Author: StanleyGoldman

src/GitHub.InlineReviews/SampleData/CommentViewModelDesigner.cs

@@ -31,6 +31,9 @@ public CommentViewModelDesigner()
         public ReactiveCommand<object> BeginCreate { get; }
         public ReactiveCommand<object> CancelCreate { get; }
         public ReactiveCommand<Unit> CommitCreate { get; }
+        public ReactiveCommand<object> BeginEdit { get; }
+        public ReactiveCommand<object> CancelEdit { get; }
+        public ReactiveCommand<Unit> CommitEdit { get; }
         public ReactiveCommand<object> OpenOnGitHub { get; }
         public ReactiveCommand<object> Delete { get; }
     }

src/GitHub.InlineReviews/ViewModels/CommentViewModel.cs

@@ -66,6 +66,13 @@ protected CommentViewModel(
 
             Delete = ReactiveCommand.Create(canDelete);
 
+            var canEdit = this.WhenAnyValue(
+                x => x.EditState,
+                x => x == CommentEditState.None && user.Login.Equals(currentUser.Login));
+
+            BeginEdit = ReactiveCommand.Create(canEdit);
+            BeginEdit.Subscribe(DoBeginEdit);
+
             var canCreate = this.WhenAnyValue(
                 x => x.EditState,
                 x => x == CommentEditState.Placeholder ||
@@ -110,6 +117,15 @@ protected void AddErrorHandler<T>(ReactiveCommand<T> command)
             command.ThrownExceptions.Subscribe(x => ErrorMessage = x.Message);
         }
 
+        void DoBeginEdit(object unused)
+        {
+            if (state != CommentEditState.Editing)
+            {
+                undoBody = Body;
+                EditState = CommentEditState.Editing;
+            }
+        }
+
         void DoBeginCreate(object unused)
         {
             if (state != CommentEditState.Creating)
@@ -221,6 +237,15 @@ public DateTimeOffset UpdatedAt
         /// <inheritdoc/>
         public ReactiveCommand<Unit> CommitCreate { get; }
 
+        /// <inheritdoc/>
+        public ReactiveCommand<object> BeginEdit { get; }
+
+        /// <inheritdoc/>
+        public ReactiveCommand<object> CancelEdit { get; }
+
+        /// <inheritdoc/>
+        public ReactiveCommand<Unit> CommitEdit { get; }
+
         /// <inheritdoc/>
         public ReactiveCommand<object> OpenOnGitHub { get; }
 

src/GitHub.InlineReviews/ViewModels/ICommentViewModel.cs

@@ -10,6 +10,7 @@ public enum CommentEditState
     {
         None,
         Creating,
+        Editing,
         Placeholder,
     }
 
@@ -70,20 +71,35 @@ public interface ICommentViewModel : IViewModel
         ICommentThreadViewModel Thread { get; }
 
         /// <summary>
-        /// Gets a command which will begin editing of the comment.
+        /// Gets a command which will begin the creation of the comment.
         /// </summary>
         ReactiveCommand<object> BeginCreate { get; }
 
         /// <summary>
-        /// Gets a command which will cancel editing of the comment.
+        /// Gets a command which will cancel the creation of the comment.
         /// </summary>
         ReactiveCommand<object> CancelCreate { get; }
 
         /// <summary>
-        /// Gets a command which will commit edits to the comment.
+        /// Gets a command which will commit the creation of the comment.
         /// </summary>
         ReactiveCommand<Unit> CommitCreate { get; }
 
+        /// <summary>
+        /// Gets a command which will begin editing of the comment.
+        /// </summary>
+        ReactiveCommand<object> BeginEdit { get; }
+
+        /// <summary>
+        /// Gets a command which will cancel editing of the comment.
+        /// </summary>
+        ReactiveCommand<object> CancelEdit { get; }
+
+        /// <summary>
+        /// Gets a command which will commit edits to the comment.
+        /// </summary>
+        ReactiveCommand<Unit> CommitEdit { get; }
+
         /// <summary>
         /// Gets a command to open the comment in a browser.
         /// </summary>

src/GitHub.InlineReviews/Views/CommentView.xaml

@@ -12,7 +12,7 @@
              xmlns:views="clr-namespace:GitHub.InlineReviews.Views"
              mc:Ignorable="d" d:DesignWidth="300">
     <d:DesignProperties.DataContext>
-        <sample:CommentViewModelDesigner EditState="None">
+        <sample:CommentViewModelDesigner EditState="Creating">
             <sample:CommentViewModelDesigner.Body>
                 You can use a `CompositeDisposable` type here, it's designed to handle disposables in an optimal way (you can just call `Dispose()` on it and it will handle disposing everything it holds).
             </sample:CommentViewModelDesigner.Body>
@@ -79,7 +79,7 @@
                                      HorizontalAlignment="Right"
                                      DockPanel.Dock="Right"/>
                 <ui:GitHubActionLink Content="Edit"
-                                     Command="{Binding BeginCreate}"
+                                     Command="{Binding BeginEdit}"
                                      Foreground="{DynamicResource GitHubVsToolWindowText}"
                                      Opacity="0.75" 
                                      HorizontalAlignment="Right"