Display PR title as pane caption.

Author: grokys

src/GitHub.App/ViewModels/Documents/IssueishPaneViewModel.cs

@@ -16,6 +16,7 @@ public class IssueishPaneViewModel : ViewModelBase, IIssueishPaneViewModel
         readonly IViewViewModelFactory factory;
         readonly IPullRequestSessionManager sessionManager;
         IViewModel content;
+        string paneCaption;
 
         [ImportingConstructor]
         public IssueishPaneViewModel(
@@ -35,6 +36,12 @@ public IViewModel Content
             private set => this.RaiseAndSetIfChanged(ref content, value);
         }
 
+        public string PaneCaption
+        {
+            get => paneCaption;
+            private set => this.RaiseAndSetIfChanged(ref paneCaption, value);
+        }
+
         public Task InitializeAsync(IServiceProvider paneServiceProvider)
         {
             return Task.CompletedTask;
@@ -43,6 +50,7 @@ public Task InitializeAsync(IServiceProvider paneServiceProvider)
         public async Task Load(IConnection connection, string owner, string name, int number)
         {
             Content = new SpinnerViewModel();
+            PaneCaption = "#" + number;
 
             // TODO: We will eventually support loading issues here as well.
             try
@@ -65,6 +73,7 @@ await vm.InitializeAsync(
                     session.User,
                     session.PullRequest).ConfigureAwait(true);
                 Content = vm;
+                PaneCaption += " " + vm.Title;
             }
             catch (Exception ex)
             {

src/GitHub.Exports/ViewModels/IPaneViewModel.cs

@@ -8,6 +8,11 @@ namespace GitHub.ViewModels
     /// </summary>
     public interface IPaneViewModel : IViewModel
     {
+        /// <summary>
+        /// Gets the caption for the tool window.
+        /// </summary>
+        string PaneCaption { get; }
+
         /// <summary>
         /// Initializes the view model.
         /// </summary>

src/GitHub.VisualStudio/UI/AsyncPaneBase.cs

@@ -8,13 +8,15 @@
 using GitHub.ViewModels;
 using Microsoft.VisualStudio.Shell;
 using Microsoft.VisualStudio.Threading;
+using ReactiveUI;
 
 namespace GitHub.VisualStudio.UI
 {
     public class AsyncPaneBase<TViewModel> : ToolWindowPane
         where TViewModel : IPaneViewModel
     {
         readonly ContentPresenter contentPresenter;
+        IDisposable subscription;
         JoinableTask<TViewModel> viewModelTask;
 
         public AsyncPaneBase()
@@ -38,6 +40,17 @@ protected override void Initialize()
 
         public Task<TViewModel> GetViewModelAsync() => viewModelTask.JoinAsync();
 
+        protected override void Dispose(bool disposing)
+        {
+            base.Dispose(disposing);
+
+            if (disposing)
+            {
+                subscription?.Dispose();
+                subscription = null;
+            }
+        }
+
         async Task<TViewModel> InitializeAsync(AsyncPackage asyncPackage)
         {
             try
@@ -55,6 +68,7 @@ async Task<TViewModel> InitializeAsync(AsyncPackage asyncPackage)
                     throw new CompositionException("Could not find view for " + typeof(TViewModel).FullName);
                 }
                 View.DataContext = viewModel;
+                subscription = viewModel.WhenAnyValue(x => x.PaneCaption).Subscribe(x => Caption = x);
                 return viewModel;
             }
             catch (Exception e)