Only enable Open file when branch checked out.

In the Pull Request Details view, disable the Open File context menu for
files unless the PR branch is checked out and when opening a file, open
the file in the working directory.

Fixes #801
Fixes #817

Author: grokys

src/GitHub.App/SampleData/PullRequestDetailViewModelDesigner.cs

@@ -84,12 +84,12 @@ public PullRequestDetailViewModelDesigner()
         public ReactiveCommand<object> OpenFile { get; }
         public ReactiveCommand<object> DiffFile { get; }
 
-        public Task<string> ExtractFile(IPullRequestFileNode file)
+        public Task<Tuple<string, string>> ExtractDiffFiles(IPullRequestFileNode file)
         {
             return null;
         }
 
-        public Task<Tuple<string, string>> ExtractDiffFiles(IPullRequestFileNode file)
+        public string GetLocalFilePath(IPullRequestFileNode file)
         {
             return null;
         }

src/GitHub.App/ViewModels/PullRequestDetailViewModel.cs

@@ -39,6 +39,7 @@ public class PullRequestDetailViewModel : BaseViewModel, IPullRequestDetailViewM
         IPullRequestCheckoutState checkoutState;
         IPullRequestUpdateState updateState;
         string operationError;
+        bool isCheckedOut;
         bool isFromFork;
         bool isInCheckout;
 
@@ -103,7 +104,7 @@ public PullRequestDetailViewModel(
             SubscribeOperationError(Push);
 
             OpenOnGitHub = ReactiveCommand.Create();
-            OpenFile = ReactiveCommand.Create();
+            OpenFile = ReactiveCommand.Create(this.WhenAnyValue(x => x.IsCheckedOut));
             DiffFile = ReactiveCommand.Create();
         }
 
@@ -145,6 +146,15 @@ public string TargetBranchDisplayName
             private set { this.RaiseAndSetIfChanged(ref targetBranchDisplayName, value); }
         }
 
+        /// <summary>
+        /// Gets a value indicating whether the pull request branch is checked out.
+        /// </summary>
+        public bool IsCheckedOut
+        {
+            get { return isCheckedOut; }
+            private set { this.RaiseAndSetIfChanged(ref isCheckedOut, value); }
+        }
+
         /// <summary>
         /// Gets a value indicating whether the pull request comes from a fork.
         /// </summary>
@@ -269,9 +279,10 @@ public async Task Load(IPullRequestModel pullRequest)
             }
 
             var localBranches = await pullRequestsService.GetLocalBranches(repository, pullRequest).ToList();
-            var isCheckedOut = localBranches.Contains(repository.CurrentBranch);
 
-            if (isCheckedOut)
+            IsCheckedOut = localBranches.Contains(repository.CurrentBranch);
+
+            if (IsCheckedOut)
             {
                 var divergence = await pullRequestsService.CalculateHistoryDivergence(repository, Model.Number);
                 var pullEnabled = divergence.BehindBy > 0;
@@ -339,17 +350,6 @@ public async Task Load(IPullRequestModel pullRequest)
             }
         }
 
-        /// <summary>
-        /// Gets the specified file as it appears in the pull request.
-        /// </summary>
-        /// <param name="file">The file or directory node.</param>
-        /// <returns>The path to the extracted file.</returns>
-        public Task<string> ExtractFile(IPullRequestFileNode file)
-        {
-            var path = Path.Combine(file.DirectoryPath, file.FileName);
-            return pullRequestsService.ExtractFile(repository, modelService, model.Head.Sha, path, file.Sha).ToTask();
-        }
-
         /// <summary>
         /// Gets the before and after files needed for viewing a diff.
         /// </summary>
@@ -361,6 +361,16 @@ public Task<Tuple<string, string>> ExtractDiffFiles(IPullRequestFileNode file)
             return pullRequestsService.ExtractDiffFiles(repository, modelService, model, path, file.Sha).ToTask();
         }
 
+        /// <summary>
+        /// Gets the full path to a file in the working directory.
+        /// </summary>
+        /// <param name="file">The file.</param>
+        /// <returns>The full path to the file in the working directory.</returns>
+        public string GetLocalFilePath(IPullRequestFileNode file)
+        {
+            return Path.Combine(repository.LocalPath, file.DirectoryPath, file.FileName);
+        }
+
         void SubscribeOperationError(ReactiveCommand<Unit> command)
         {
             command.ThrownExceptions.Subscribe(x => OperationError = x.Message);

src/GitHub.Exports.Reactive/ViewModels/IPullRequestDetailViewModel.cs

@@ -139,18 +139,18 @@ public interface IPullRequestDetailViewModel : IViewModel, IHasBusy
         /// </summary>
         ReactiveCommand<object> DiffFile { get; }
 
-        /// <summary>
-        /// Gets the specified file as it appears in the pull request.
-        /// </summary>
-        /// <param name="file">The file or directory node.</param>
-        /// <returns>The path to the extracted file.</returns>
-        Task<string> ExtractFile(IPullRequestFileNode file);
-
         /// <summary>
         /// Gets the before and after files needed for viewing a diff.
         /// </summary>
         /// <param name="file">The changed file.</param>
         /// <returns>A tuple containing the full path to the before and after files.</returns>
         Task<Tuple<string, string>> ExtractDiffFiles(IPullRequestFileNode file);
+
+        /// <summary>
+        /// Gets the full path to a file in the working directory.
+        /// </summary>
+        /// <param name="file">The file.</param>
+        /// <returns>The full path to the file in the working directory.</returns>
+        string GetLocalFilePath(IPullRequestFileNode file);
     }
 }

src/GitHub.VisualStudio/UI/Views/PullRequestDetailView.xaml

@@ -286,8 +286,8 @@
                                 <!-- When invoked from the TreeView and the ListView we programmatically bind the 
                                      DataContext and update the CommandParameter to the changed file -->
                                 <ContextMenu x:Key="FileContextMenu">
-                                    <MenuItem Header="{x:Static prop:Resources.OpenFile}" Command="{Binding OpenFile}"/>
                                     <MenuItem Header="{x:Static prop:Resources.CompareFile}" Command="{Binding DiffFile}"/>
+                                    <MenuItem Header="{x:Static prop:Resources.OpenFile}" Command="{Binding OpenFile}"/>
                                 </ContextMenu>
                             </Grid.Resources>
 

src/GitHub.VisualStudio/UI/Views/PullRequestDetailView.xaml.cs

@@ -41,7 +41,7 @@ public PullRequestDetailView()
             this.WhenActivated(d =>
             {
                 d(ViewModel.OpenOnGitHub.Subscribe(_ => DoOpenOnGitHub()));
-                d(ViewModel.OpenFile.Subscribe(x => DoOpenFile((IPullRequestFileNode)x).Forget()));
+                d(ViewModel.OpenFile.Subscribe(x => DoOpenFile((IPullRequestFileNode)x)));
                 d(ViewModel.DiffFile.Subscribe(x => DoDiffFile((IPullRequestFileNode)x).Forget()));
             });
         }
@@ -65,15 +65,12 @@ void DoOpenOnGitHub()
             browser.OpenUrl(url);
         }
 
-        async Task DoOpenFile(IPullRequestFileNode file)
+        void DoOpenFile(IPullRequestFileNode file)
         {
             try
             {
-                var fileName = await ViewModel.ExtractFile(file);
-                var window = Services.Dte.ItemOperations.OpenFile(fileName);
-
-                // If the file we extracted isn't the current file on disk, make the window read-only.
-                window.Document.ReadOnly = fileName != file.DirectoryPath;
+                var fileName = ViewModel.GetLocalFilePath(file);
+                Services.Dte.ItemOperations.OpenFile(fileName);
             }
             catch (Exception e)
             {