Add a UIContext to signal active Git repository

Author: jcansdale

src/GitHub.Exports/Settings/Guids.cs

@@ -21,6 +21,9 @@ public static class Guids
         public const string GitSccProviderId = "11B8E6D7-C08B-4385-B321-321078CDD1F8";
         public const string TeamExplorerInstall3rdPartyGitTools = "DF785C7C-8454-4836-9686-D1C4A01D0BB9";
 
+        // UIContexts
+        public const string UIContext_Git = "565515AD-F4C1-4D59-BC14-AE77396DDDD7";
+
         // Guids defined in GitHub.VisualStudio.vsct
         public const string guidGitHubPkgString = "c3d3dc68-c977-411f-b3e8-03b0dccf7dfc";
         public const string guidAssemblyResolverPkgString = "a6424dba-34cb-360d-a4de-1b0b0411e57d";

src/GitHub.VisualStudio/GitContextPackage.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Threading;
+using System.Runtime.InteropServices;
+using Microsoft.VisualStudio.Shell;
+using GitHub.Services;
+using Task = System.Threading.Tasks.Task;
+
+namespace GitHub.VisualStudio
+{
+    /// <summary>
+    /// This package creates a custom UIContext <see cref="Guids.UIContext_Git"/> that is activated when a
+    /// repository is active in <see cref="IVSGitExt"/>.
+    /// </summary>
+    [PackageRegistration(UseManagedResourcesOnly = true, AllowsBackgroundLoading = true)]
+    [Guid(Guids.UIContext_Git)]
+    // this is the Git service GUID, so we load whenever it loads
+    [ProvideAutoLoad(Guids.GitSccProviderId, PackageAutoLoadFlags.BackgroundLoad)]
+    public class GitContextPackage : AsyncPackage
+    {
+        protected async override Task InitializeAsync(CancellationToken cancellationToken, IProgress<ServiceProgressData> progress)
+        {
+            var gitExt = (IVSGitExt)await GetServiceAsync(typeof(IVSGitExt));
+            var context = UIContext.FromUIContextGuid(new Guid(Guids.UIContext_Git));
+            RefreshContext(context, gitExt);
+            gitExt.ActiveRepositoriesChanged += () =>
+            {
+                RefreshContext(context, gitExt);
+            };
+        }
+
+        static void RefreshContext(UIContext context, IVSGitExt gitExt)
+        {
+            context.IsActive = gitExt.ActiveRepositories.Count > 0;
+        }
+    }
+}

src/GitHub.VisualStudio/GitHub.VisualStudio.csproj

@@ -306,6 +306,7 @@
       <Link>Properties\SolutionInfo.cs</Link>
     </Compile>
     <Compile Include="AssemblyResolverPackage.cs" />
+    <Compile Include="GitContextPackage.cs" />
     <Compile Include="IServiceProviderPackage.cs" />
     <Compile Include="Menus\BlameLink.cs" />
     <Compile Include="Menus\MenuBase.cs" />