Merge pull request #1426 from github/fixes/githubpane-initialization

Ensure that the GitHubPaneViewModel is initalized.

Author: grokys

src/GitHub.App/ViewModels/GitHubPane/GitHubPaneViewModel.cs

@@ -46,6 +46,8 @@ public sealed class GitHubPaneViewModel : ViewModelBase, IGitHubPaneViewModel, I
         readonly ReactiveCommand<Unit> refresh;
         readonly ReactiveCommand<Unit> showPullRequests;
         readonly ReactiveCommand<object> openInBrowser;
+        readonly SemaphoreSlim initializing = new SemaphoreSlim(1);
+        bool initialized;
         IViewModel content;
         ILocalRepositoryModel localRepository;
         string searchQuery;
@@ -198,26 +200,37 @@ public void Dispose()
         /// <inheritdoc/>
         public async Task InitializeAsync(IServiceProvider paneServiceProvider)
         {
-            await UpdateContent(teamExplorerContext.ActiveRepository);
-            teamExplorerContext.WhenAnyValue(x => x.ActiveRepository)
-               .Skip(1)
-               .ObserveOn(RxApp.MainThreadScheduler)
-               .Subscribe(x => UpdateContent(x).Forget());
-
-            connectionManager.Connections.CollectionChanged += (_, __) => UpdateContent(LocalRepository).Forget();
-
-            BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.pullRequestCommand, showPullRequests);
-            BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.backCommand, navigator.NavigateBack);
-            BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.forwardCommand, navigator.NavigateForward);
-            BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.refreshCommand, refresh);
-            BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.githubCommand, openInBrowser);
-
-            paneServiceProvider.AddCommandHandler(Guids.guidGitHubToolbarCmdSet, PkgCmdIDList.helpCommand,
-                 (_, __) =>
-                 {
-                     browser.OpenUrl(new Uri(GitHubUrls.Documentation));
-                     usageTracker.IncrementCounter(x => x.NumberOfGitHubPaneHelpClicks).Forget();
-                 });
+            await initializing.WaitAsync();
+            if (initialized) return;
+
+            try
+            {
+                await UpdateContent(teamExplorerContext.ActiveRepository);
+                teamExplorerContext.WhenAnyValue(x => x.ActiveRepository)
+                   .Skip(1)
+                   .ObserveOn(RxApp.MainThreadScheduler)
+                   .Subscribe(x => UpdateContent(x).Forget());
+
+                connectionManager.Connections.CollectionChanged += (_, __) => UpdateContent(LocalRepository).Forget();
+
+                BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.pullRequestCommand, showPullRequests);
+                BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.backCommand, navigator.NavigateBack);
+                BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.forwardCommand, navigator.NavigateForward);
+                BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.refreshCommand, refresh);
+                BindNavigatorCommand(paneServiceProvider, PkgCmdIDList.githubCommand, openInBrowser);
+
+                paneServiceProvider.AddCommandHandler(Guids.guidGitHubToolbarCmdSet, PkgCmdIDList.helpCommand,
+                     (_, __) =>
+                     {
+                         browser.OpenUrl(new Uri(GitHubUrls.Documentation));
+                         usageTracker.IncrementCounter(x => x.NumberOfGitHubPaneHelpClicks).Forget();
+                     });
+            }
+            finally
+            {
+                initialized = true;
+                initializing.Release();
+            }
         }
 
         /// <inheritdoc/>

src/GitHub.Exports.Reactive/Services/IPullRequestSessionManager.cs

@@ -31,6 +31,18 @@ public interface IPullRequestSessionManager : INotifyPropertyChanged
         /// </returns>
         IPullRequestSession CurrentSession { get; }
 
+        /// <summary>
+        /// Ensures that the service is initialized.
+        /// </summary>
+        /// <returns>A task that when completed indicates that the service is initialized.</returns>
+        /// <remarks>
+        /// If you are simply monitoring changes to the <see cref="CurrentSession"/> then you
+        /// don't need to call this method: <see cref="CurrentSession"/> will be updated on
+        /// initialization. If however, you want to be sure that <see cref="CurrentSession"/> is
+        /// initialized, you can await the task returned from this method.
+        /// </remarks>
+        Task EnsureInitialized();
+
         /// <summary>
         /// Gets an <see cref="IPullRequestSessionFile"/> that tracks the live state of a document.
         /// </summary>

src/GitHub.InlineReviews/Services/PullRequestSessionManager.cs

@@ -36,6 +36,7 @@ public class PullRequestSessionManager : ReactiveObject, IPullRequestSessionMana
         readonly IModelServiceFactory modelServiceFactory;
         readonly Dictionary<Tuple<string, int>, WeakReference<PullRequestSession>> sessions =
             new Dictionary<Tuple<string, int>, WeakReference<PullRequestSession>>();
+        TaskCompletionSource<object> initialized;
         IPullRequestSession currentSession;
         ILocalRepositoryModel repository;
 
@@ -65,6 +66,7 @@ public PullRequestSessionManager(
             this.sessionService = sessionService;
             this.connectionManager = connectionManager;
             this.modelServiceFactory = modelServiceFactory;
+            initialized = new TaskCompletionSource<object>(null);
 
             Observable.FromEventPattern(teamExplorerContext, nameof(teamExplorerContext.StatusChanged))
                 .ObserveOn(RxApp.MainThreadScheduler)
@@ -82,6 +84,10 @@ public IPullRequestSession CurrentSession
             private set { this.RaiseAndSetIfChanged(ref currentSession, value); }
         }
 
+        /// <inheritdoc/>
+        public Task EnsureInitialized() => initialized.Task;
+
+        /// <inheritdoc/>
         public async Task<IPullRequestSessionFile> GetLiveFile(
             string relativePath,
             ITextView textView,
@@ -230,6 +236,7 @@ async Task StatusChanged()
                 }
 
                 CurrentSession = session;
+                initialized.SetResult(null);
             }
             catch (Exception e)
             {

src/GitHub.VisualStudio/GitHubPackage.cs

@@ -158,7 +158,7 @@ protected override Task InitializeAsync(CancellationToken cancellationToken, IPr
             return Task.CompletedTask;
         }
 
-        public IGitHubPaneViewModel ShowHomePane()
+        public async Task<IGitHubPaneViewModel> ShowGitHubPane()
         {
             var pane = ShowToolWindow(new Guid(GitHubPane.GitHubPaneGuid));
             if (pane == null)
@@ -168,7 +168,10 @@ public IGitHubPaneViewModel ShowHomePane()
             {
                 ErrorHandler.Failed(frame.Show());
             }
-            return (IGitHubPaneViewModel)((FrameworkElement)pane.Content).DataContext;
+
+            var viewModel = (IGitHubPaneViewModel)((FrameworkElement)pane.Content).DataContext;
+            await viewModel.InitializeAsync(pane);
+            return viewModel;
         }
 
         static ToolWindowPane ShowToolWindow(Guid windowGuid)

src/GitHub.VisualStudio/IServiceProviderPackage.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Threading.Tasks;
 using GitHub.ViewModels.GitHubPane;
 
 namespace GitHub.VisualStudio
@@ -12,6 +13,6 @@ public interface IServiceProviderPackage : IServiceProvider, Microsoft.VisualStu
     [ComVisible(true)]
     public interface IGitHubToolWindowManager
     {
-        IGitHubPaneViewModel ShowHomePane();
+        Task<IGitHubPaneViewModel> ShowGitHubPane();
     }
 }

src/GitHub.VisualStudio/Menus/OpenPullRequests.cs

@@ -1,15 +1,17 @@
-using GitHub.Exports;
-using GitHub.UI;
-using GitHub.VisualStudio.UI;
-using System;
-using GitHub.Services;
+using System;
+using GitHub.Exports;
 using GitHub.Extensions;
+using GitHub.Logging;
+using GitHub.Services;
+using Serilog;
 
 namespace GitHub.VisualStudio.Menus
 {
     [ExportMenu(MenuType = MenuType.OpenPullRequests)]
     public class OpenPullRequests : MenuBase, IMenuHandler
     {
+        static readonly ILogger log = LogManager.ForContext<ShowCurrentPullRequest>();
+
         public OpenPullRequests(IGitHubServiceProvider serviceProvider)
             : base(serviceProvider)
         {
@@ -19,10 +21,17 @@ public OpenPullRequests(IGitHubServiceProvider serviceProvider)
         public Guid Guid => Guids.guidGitHubCmdSet;
         public int CmdId => PkgCmdIDList.openPullRequestsCommand;
 
-        public void Activate(object data = null)
+        public async void Activate(object data = null)
         {
-            var host = ServiceProvider.TryGetService<IGitHubToolWindowManager>().ShowHomePane();
-            host.ShowPullRequests().Forget();
+            try
+            {
+                var host = await ServiceProvider.TryGetService<IGitHubToolWindowManager>().ShowGitHubPane();
+                await host.ShowPullRequests();
+            }
+            catch (Exception ex)
+            {
+                log.Error(ex, "Error showing opening pull requests");
+            }
         }
     }
 }

src/GitHub.VisualStudio/Menus/ShowCurrentPullRequest.cs

@@ -1,15 +1,17 @@
 using System;
 using GitHub.Exports;
-using GitHub.UI;
-using GitHub.Services;
 using GitHub.Extensions;
-using GitHub.Models;
+using GitHub.Logging;
+using GitHub.Services;
+using Serilog;
 
 namespace GitHub.VisualStudio.Menus
 {
     [ExportMenu(MenuType = MenuType.OpenPullRequests)]
     public class ShowCurrentPullRequest : MenuBase, IMenuHandler
     {
+        static readonly ILogger log = LogManager.ForContext<ShowCurrentPullRequest>();
+
         public ShowCurrentPullRequest(IGitHubServiceProvider serviceProvider)
             : base(serviceProvider)
         {
@@ -19,19 +21,28 @@ public ShowCurrentPullRequest(IGitHubServiceProvider serviceProvider)
         public Guid Guid => Guids.guidGitHubCmdSet;
         public int CmdId => PkgCmdIDList.showCurrentPullRequestCommand;
 
-        public void Activate(object data = null)
+        public async void Activate(object data = null)
         {
-            var pullRequestSessionManager = ServiceProvider.ExportProvider.GetExportedValueOrDefault<IPullRequestSessionManager>();
-            var session = pullRequestSessionManager?.CurrentSession;
-            if (session == null)
+            try
             {
-                return; // No active PR session.
-            }
+                var pullRequestSessionManager = ServiceProvider.ExportProvider.GetExportedValueOrDefault<IPullRequestSessionManager>();
+                await pullRequestSessionManager.EnsureInitialized();
 
-            var pullRequest = session.PullRequest;
-            var manager = ServiceProvider.TryGetService<IGitHubToolWindowManager>();
-            var host = manager.ShowHomePane();
-            host.ShowPullRequest(session.RepositoryOwner, host.LocalRepository.Name, pullRequest.Number);
+                var session = pullRequestSessionManager?.CurrentSession;
+                if (session == null)
+                {
+                    return; // No active PR session.
+                }
+
+                var pullRequest = session.PullRequest;
+                var manager = ServiceProvider.TryGetService<IGitHubToolWindowManager>();
+                var host = await manager.ShowGitHubPane();
+                await host.ShowPullRequest(session.RepositoryOwner, host.LocalRepository.Name, pullRequest.Number);
+            }
+            catch (Exception ex)
+            {
+                log.Error(ex, "Error showing current pull request");
+            }
         }
     }
 }

src/GitHub.VisualStudio/Menus/ShowGitHubPane.cs

@@ -17,7 +17,7 @@ public ShowGitHubPane(IGitHubServiceProvider serviceProvider)
 
         public void Activate(object data = null)
         {
-            ServiceProvider.TryGetService<IGitHubToolWindowManager>()?.ShowHomePane();
+            ServiceProvider.TryGetService<IGitHubToolWindowManager>()?.ShowGitHubPane();
         }
     }
 }