Fix navigation in findrefs

src/VisualStudio/Core/Def/Implementation/FindReferences/Entries/DocumentSpanEntry.cs

@@ -36,7 +36,7 @@ internal partial class StreamingFindUsagesPresenter
         /// contents of that line, and hovering will reveal a tooltip showing that line along
         /// with a few lines above/below it.
         /// </summary>
-        private class DocumentSpanEntry : AbstractDocumentSpanEntry, ISupportsNavigation
+        private sealed class DocumentSpanEntry : AbstractDocumentSpanEntry, ISupportsNavigation
         {
             private readonly HighlightSpanKind _spanKind;
             private readonly ExcerptResult _excerptResult;
@@ -280,30 +280,37 @@ private static Span GetRegionSpanForReference(SourceText sourceText, TextSpan so
                     sourceText.Lines[lastLineNumber].End);
             }
 
-            async Task<bool> ISupportsNavigation.TryNavigateToAsync(bool isPreview, CancellationToken cancellationToken)
+            public bool CanNavigateTo()
             {
-                // If the document is a source generated document, we need to do the navigation ourselves;
-                // this is because the file path given to the table control isn't a real file path to a file
-                // on disk.
                 if (_excerptResult.Document is SourceGeneratedDocument)
                 {
                     var workspace = _excerptResult.Document.Project.Solution.Workspace;
                     var documentNavigationService = workspace.Services.GetService<IDocumentNavigationService>();
 
-                    if (documentNavigationService != null)
-                    {
-                        await this.Presenter.ThreadingContext.JoinableTaskFactory.SwitchToMainThreadAsync(cancellationToken);
-                        return documentNavigationService.TryNavigateToSpan(
-                            workspace,
-                            _excerptResult.Document.Id,
-                            _excerptResult.Span,
-                            workspace.Options.WithChangedOption(NavigationOptions.PreferProvisionalTab, isPreview),
-                            cancellationToken);
-                    }
+                    return documentNavigationService != null;
                 }
 
                 return false;
             }
+
+            public Task NavigateToAsync(bool isPreview, CancellationToken cancellationToken)
+            {
+                Contract.ThrowIfFalse(CanNavigateTo());
+
+                // If the document is a source generated document, we need to do the navigation ourselves;
+                // this is because the file path given to the table control isn't a real file path to a file
+                // on disk.
+
+                var workspace = _excerptResult.Document.Project.Solution.Workspace;
+                var documentNavigationService = workspace.Services.GetRequiredService<IDocumentNavigationService>();
+
+                return documentNavigationService.TryNavigateToSpanAsync(
+                    workspace,
+                    _excerptResult.Document.Id,
+                    _excerptResult.Span,
+                    workspace.Options.WithChangedOption(NavigationOptions.PreferProvisionalTab, isPreview),
+                    cancellationToken);
+            }
         }
     }
 }

src/VisualStudio/Core/Def/Implementation/FindReferences/Entries/Entry.cs

@@ -3,6 +3,8 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+using System.Threading.Tasks;
 using System.Windows;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.Editor.Wpf;

src/VisualStudio/Core/Def/Implementation/FindReferences/Entries/MetadataDefinitionItemEntry.cs

@@ -34,13 +34,16 @@ public MetadataDefinitionItemEntry(
                 return null;
             }
 
-            Task<bool> ISupportsNavigation.TryNavigateToAsync(bool isPreview, CancellationToken cancellationToken)
+            public bool CanNavigateTo()
+                => true;
+
+            public Task NavigateToAsync(bool isPreview, CancellationToken cancellationToken)
                 => DefinitionBucket.DefinitionItem.TryNavigateToAsync(
                     Presenter._workspace, showInPreviewTab: isPreview, activateTab: !isPreview, cancellationToken); // Only activate the tab if not opening in preview
 
             protected override IList<Inline> CreateLineTextInlines()
                 => DefinitionBucket.DefinitionItem.DisplayParts
-                .ToInlines(Presenter.ClassificationFormatMap, Presenter.TypeMap);
+                    .ToInlines(Presenter.ClassificationFormatMap, Presenter.TypeMap);
         }
     }
 }

src/VisualStudio/Core/Def/Implementation/FindReferences/Entries/SimpleMessageEntry.cs

@@ -5,12 +5,13 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.VisualStudio.Shell.TableManager;
+using Roslyn.Utilities;
 
 namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
     internal partial class StreamingFindUsagesPresenter
     {
-        private class SimpleMessageEntry : Entry, ISupportsNavigation
+        private sealed class SimpleMessageEntry : Entry, ISupportsNavigation
         {
             private readonly RoslynDefinitionBucket? _navigationBucket;
             private readonly string _message;
@@ -44,8 +45,15 @@ public static Task<Entry> CreateAsync(
                 };
             }
 
-            public async Task<bool> TryNavigateToAsync(bool isPreview, CancellationToken cancellationToken)
-                => _navigationBucket != null && await _navigationBucket.TryNavigateToAsync(isPreview, cancellationToken).ConfigureAwait(false);
+            public bool CanNavigateTo()
+                => _navigationBucket != null && _navigationBucket.CanNavigateTo();
+
+            public Task NavigateToAsync(bool isPreview, CancellationToken cancellationToken)
+            {
+                Contract.ThrowIfFalse(CanNavigateTo());
+                Contract.ThrowIfNull(_navigationBucket);
+                return _navigationBucket.NavigateToAsync(isPreview, cancellationToken);
+            }
         }
     }
 }

src/VisualStudio/Core/Def/Implementation/FindReferences/FindReferencesTableControlEventProcessorProvider.cs

@@ -59,16 +59,15 @@ public override void PreprocessNavigate(ITableEntryHandle entry, TableEntryNavig
             {
                 var supportsNavigation = entry.Identity as ISupportsNavigation ??
                     (entry.TryGetValue(StreamingFindUsagesPresenter.SelfKeyName, out var item) ? item as ISupportsNavigation : null);
-                if (supportsNavigation == null)
+                if (supportsNavigation != null &&
+                    supportsNavigation.CanNavigateTo())
                 {
-                    base.PreprocessNavigate(entry, e);
-                    return;
+                    // Fire and forget
+                    e.Handled = true;
+                    _ = ProcessNavigateAsync(supportsNavigation, e, _listener, _operationExecutor);
                 }
 
-                // Fire and forget
-                e.Handled = true;
-                _ = ProcessNavigateAsync(supportsNavigation, e, _listener, _operationExecutor);
-
+                base.PreprocessNavigate(entry, e);
                 return;
 
                 async static Task ProcessNavigateAsync(
@@ -83,7 +82,7 @@ async static Task ProcessNavigateAsync(
                         allowCancellation: true,
                         showProgress: false);
 
-                    await supportsNavigation.TryNavigateToAsync(e.IsPreview, context.UserCancellationToken).ConfigureAwait(false);
+                    await supportsNavigation.NavigateToAsync(e.IsPreview, context.UserCancellationToken).ConfigureAwait(false);
                 }
             }
         }

src/VisualStudio/Core/Def/Implementation/FindReferences/ISupportsNavigation.cs

@@ -9,6 +9,7 @@ namespace Microsoft.VisualStudio.LanguageServices.FindUsages
 {
     internal interface ISupportsNavigation
     {
-        Task<bool> TryNavigateToAsync(bool isPreview, CancellationToken cancellationToken);
+        bool CanNavigateTo();
+        Task NavigateToAsync(bool isPreview, CancellationToken cancellationToken);
     }
 }

src/VisualStudio/Core/Def/Implementation/FindReferences/RoslynDefinitionBucket.cs

@@ -63,7 +63,10 @@ public static RoslynDefinitionBucket Create(
                     name, expandedByDefault, presenter, context, definitionItem);
             }
 
-            public Task<bool> TryNavigateToAsync(bool isPreview, CancellationToken cancellationToken)
+            public bool CanNavigateTo()
+                => true;
+
+            public Task NavigateToAsync(bool isPreview, CancellationToken cancellationToken)
                 => DefinitionItem.TryNavigateToAsync(
                     _presenter._workspace, showInPreviewTab: isPreview, activateTab: !isPreview, cancellationToken); // Only activate the tab if not opening in preview