Merge pull request #8890 from rchande/sighelpperf2

Cancel the signature help if the user navigates before it has been presented

src/EditorFeatures/Core/Extensibility/SignatureHelp/ISignatureHelpPresenterSession.cs

@@ -13,5 +13,7 @@ internal interface ISignatureHelpPresenterSession : IIntelliSensePresenterSessio
         void SelectNextItem();
 
         event EventHandler<SignatureHelpItemEventArgs> ItemSelected;
+
+        bool EditorSessionIsActive { get; }
     }
 }

src/EditorFeatures/Core/Implementation/IntelliSense/SignatureHelp/Controller_NavigationKeys.cs

@@ -28,6 +28,15 @@ private bool ChangeSelection(Action computationAction)
                 return false;
             }
 
+            // If we haven't started our editor session yet, just abort.
+            // The user hasn't seen a SigHelp presentation yet, so they're
+            // probably not trying to change the currently visible overload.
+            if (!sessionOpt.PresenterSession.EditorSessionIsActive)
+            {
+                DismissSessionIfActive();
+                return false;
+            }
+
             // If we've finished computing the items then use the navigation commands to change the
             // selected item.  Otherwise, the user was just typing and is now moving through the
             // file.  In this case stop everything we're doing.

src/EditorFeatures/Core/Implementation/IntelliSense/SignatureHelp/Presentation/SignatureHelpPresenter.SignatureHelpPresenterSession.cs

@@ -31,6 +31,8 @@ private class SignatureHelpPresenterSession : ForegroundThreadAffinitizedObject,
             private ISignatureHelpSession _editorSessionOpt;
             private bool _ignoreSelectionStatusChangedEvent;
 
+            public bool EditorSessionIsActive => _editorSessionOpt?.IsDismissed == false;
+
             public SignatureHelpPresenterSession(
                 ISignatureHelpBroker sigHelpBroker,
                 ITextView textView,

src/EditorFeatures/Test2/IntelliSense/SignatureHelpControllerTests.vb

 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-Imports System.ComponentModel.Composition.Hosting
 Imports System.Runtime.CompilerServices
 Imports System.Threading
 Imports System.Threading.Tasks
+Imports System.Windows.Threading
 Imports Microsoft.CodeAnalysis.Editor.Commands
 Imports Microsoft.CodeAnalysis.Editor.Implementation.IntelliSense
 Imports Microsoft.CodeAnalysis.Editor.Implementation.IntelliSense.SignatureHelp
@@ -13,7 +13,6 @@ Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.VisualStudio.Language.Intellisense
 Imports Microsoft.VisualStudio.Text
 Imports Microsoft.VisualStudio.Text.Editor
-Imports Microsoft.VisualStudio.Text.Projection
 Imports Moq
 
 #Disable Warning RS0007 ' Avoid zero-length array allocations. This is non-shipping test code.
@@ -93,6 +92,79 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
             GetMocks(controller).PresenterSession.Verify(Sub(p) p.Dismiss(), Times.Once)
         End Sub
 
+        <WpfFact>
+        <WorkItem(179726, "https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workItems?id=179726&_a=edit")>
+        Public Sub DownKeyShouldNotBlockOnModelComputation()
+            Dim mre = New ManualResetEvent(False)
+            Dim controller = CreateController(items:=CreateItems(2), waitForPresentation:=False)
+            Dim slowProvider = New Mock(Of ISignatureHelpProvider)
+            slowProvider.Setup(Function(p) p.GetItemsAsync(It.IsAny(Of Document), It.IsAny(Of Integer), It.IsAny(Of SignatureHelpTriggerInfo), It.IsAny(Of CancellationToken))) _
+                .Returns(Function()
+                             mre.WaitOne()
+                             Return Task.FromResult(New SignatureHelpItems(CreateItems(2), TextSpan.FromBounds(0, 0), selectedItem:=0, argumentIndex:=0, argumentCount:=0, argumentName:=Nothing))
+                         End Function)
+
+
+            Dim handled = controller.TryHandleDownKey()
+
+            Assert.False(handled)
+        End Sub
+
+        <WpfFact>
+        <WorkItem(179726, "https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workItems?id=179726&_a=edit")>
+        Public Sub UpKeyShouldNotBlockOnModelComputation()
+            Dim mre = New ManualResetEvent(False)
+            Dim controller = CreateController(items:=CreateItems(2), waitForPresentation:=False)
+            Dim slowProvider = New Mock(Of ISignatureHelpProvider)
+            slowProvider.Setup(Function(p) p.GetItemsAsync(It.IsAny(Of Document), It.IsAny(Of Integer), It.IsAny(Of SignatureHelpTriggerInfo), It.IsAny(Of CancellationToken))) _
+                .Returns(Function()
+                             mre.WaitOne()
+                             Return Task.FromResult(New SignatureHelpItems(CreateItems(2), TextSpan.FromBounds(0, 0), selectedItem:=0, argumentIndex:=0, argumentCount:=0, argumentName:=Nothing))
+                         End Function)
+
+
+            Dim handled = controller.TryHandleUpKey()
+
+            Assert.False(handled)
+        End Sub
+
+        <WpfFact>
+        <WorkItem(179726, "https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workItems?id=179726&_a=edit")>
+        Public Async Function UpKeyShouldBlockOnRecomputationAfterPresentation() As Task
+            Dim dispatcher = System.Windows.Threading.Dispatcher.CurrentDispatcher
+            Dim worker = Async Function()
+                             Dim slowProvider = New Mock(Of ISignatureHelpProvider)
+                             slowProvider.Setup(Function(p) p.GetItemsAsync(It.IsAny(Of Document), It.IsAny(Of Integer), It.IsAny(Of SignatureHelpTriggerInfo), It.IsAny(Of CancellationToken))) _
+                                 .Returns(Task.FromResult(New SignatureHelpItems(CreateItems(2), TextSpan.FromBounds(0, 0), selectedItem:=0, argumentIndex:=0, argumentCount:=0, argumentName:=Nothing)))
+
+                             Dim controller = dispatcher.Invoke(Function() CreateController(provider:=slowProvider.Object, waitForPresentation:=True))
+
+                             ' Update session so that providers are requeried.
+                             ' SlowProvider now blocks on the checkpoint's task.
+                             Dim checkpoint = New Checkpoint()
+                             slowProvider.Setup(Function(p) p.GetItemsAsync(It.IsAny(Of Document), It.IsAny(Of Integer), It.IsAny(Of SignatureHelpTriggerInfo), It.IsAny(Of CancellationToken))) _
+                                 .Returns(Function()
+                                              checkpoint.Task.Wait()
+                                              Return Task.FromResult(New SignatureHelpItems(CreateItems(2), TextSpan.FromBounds(0, 2), selectedItem:=0, argumentIndex:=0, argumentCount:=0, argumentName:=Nothing))
+                                          End Function)
+
+                             dispatcher.Invoke(Sub() DirectCast(controller, ICommandHandler(Of TypeCharCommandArgs)).ExecuteCommand(
+                                 New TypeCharCommandArgs(CreateMock(Of ITextView), CreateMock(Of ITextBuffer), " "c),
+                                 Sub() GetMocks(controller).Buffer.Insert(0, " ")))
+
+                             Dim handled = dispatcher.InvokeAsync(Function() controller.TryHandleUpKey()) ' Send the controller an up key, which should block on the computation
+                             checkpoint.Release() ' Allow slowprovider to finish
+                             Await handled.Task.ConfigureAwait(False)
+
+                             ' We expect 2 calls to the presenter (because we had an existing presentation session when we started the second computation).
+                             Assert.True(handled.Result)
+                             GetMocks(controller).PresenterSession.Verify(Sub(p) p.PresentItems(It.IsAny(Of ITrackingSpan), It.IsAny(Of IList(Of SignatureHelpItem)),
+                                                                                                It.IsAny(Of SignatureHelpItem), It.IsAny(Of Integer?)), Times.Exactly(2))
+                         End Function
+            Await worker().ConfigureAwait(False)
+
+        End Function
+
         <WpfFact>
         Public Sub DownKeyShouldNavigateWhenThereAreMultipleItems()
             Dim controller = CreateController(items:=CreateItems(2), waitForPresentation:=True)
@@ -195,6 +267,9 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
             Dim presenter = New Mock(Of IIntelliSensePresenter(Of ISignatureHelpPresenterSession, ISignatureHelpSession)) With {.DefaultValue = DefaultValue.Mock}
             presenterSession = If(presenterSession, New Mock(Of ISignatureHelpPresenterSession) With {.DefaultValue = DefaultValue.Mock})
             presenter.Setup(Function(p) p.CreateSession(It.IsAny(Of ITextView), It.IsAny(Of ITextBuffer), It.IsAny(Of ISignatureHelpSession))).Returns(presenterSession.Object)
+            presenterSession.Setup(Sub(p) p.PresentItems(It.IsAny(Of ITrackingSpan), It.IsAny(Of IList(Of SignatureHelpItem)), It.IsAny(Of SignatureHelpItem), It.IsAny(Of Integer?))) _
+                .Callback(Sub() presenterSession.SetupGet(Function(p) p.EditorSessionIsActive).Returns(True))
+
 
             Dim controller = New Controller(
                 view.Object,

src/EditorFeatures/Test2/IntelliSense/TestSignatureHelpPresenterSession.vb

@@ -13,6 +13,13 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
         Public SignatureHelpItems As IList(Of SignatureHelpItem)
         Public SelectedItem As SignatureHelpItem
         Public SelectedParameter As Integer?
+        Private presented As Boolean = False
+
+        Public ReadOnly Property EditorSessionIsActive As Boolean Implements ISignatureHelpPresenterSession.EditorSessionIsActive
+            Get
+                Return presented
+            End Get
+        End Property
 
         Public Event Dismissed As EventHandler(Of EventArgs) Implements ISignatureHelpPresenterSession.Dismissed
         Public Event ItemSelected As EventHandler(Of SignatureHelpItemEventArgs) Implements ISignatureHelpPresenterSession.ItemSelected
@@ -30,10 +37,12 @@ Namespace Microsoft.CodeAnalysis.Editor.UnitTests.IntelliSense
             Me.SignatureHelpItems = signatureHelpItems
             Me.SelectedItem = selectedItem
             Me.SelectedParameter = selectedParameter
+            Me.presented = True
         End Sub
 
         Public Sub Dismiss() Implements ISignatureHelpPresenterSession.Dismiss
             _testState.CurrentSignatureHelpPresenterSession = Nothing
+            Me.presented = False
         End Sub
 
         Public Sub SetSelectedItem(item As SignatureHelpItem)