File: LineCommit\CommitCommandHandler.vb
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Project: src\src\EditorFeatures\VisualBasic\Microsoft.CodeAnalysis.VisualBasic.EditorFeatures.vbproj (Microsoft.CodeAnalysis.VisualBasic.EditorFeatures)
' Licensed to the .NET Foundation under one or more agreements.
' The .NET Foundation licenses this file to you under the MIT license.
' See the LICENSE file in the project root for more information.
 
Imports System.ComponentModel.Composition
Imports System.Diagnostics.CodeAnalysis
Imports System.Threading
Imports Microsoft.CodeAnalysis
Imports Microsoft.CodeAnalysis.Editor.Shared.Utilities
Imports Microsoft.CodeAnalysis.Formatting
Imports Microsoft.CodeAnalysis.Formatting.Rules
Imports Microsoft.CodeAnalysis.Options
Imports Microsoft.CodeAnalysis.Text
Imports Microsoft.CodeAnalysis.Text.Shared.Extensions
Imports Microsoft.VisualStudio.Commanding
Imports Microsoft.VisualStudio.Language.Intellisense.AsyncCompletion
Imports Microsoft.VisualStudio.Text
Imports Microsoft.VisualStudio.Text.Editor
Imports Microsoft.VisualStudio.Text.Editor.Commanding.Commands
Imports Microsoft.VisualStudio.Text.Operations
Imports Microsoft.VisualStudio.Utilities
 
Namespace Microsoft.CodeAnalysis.Editor.VisualBasic.LineCommit
    ''' <summary>
    ''' Watches for the enter key being pressed, and triggers a commit in response.
    ''' </summary>
    ''' <remarks>This particular command filter acts as a "wrapper" around any other command, as it
    ''' wishes to invoke the commit after whatever processed the enter is done doing what it's
    ''' doing.</remarks>
    <Export(GetType(ICommandHandler))>
    <ContentType(ContentTypeNames.VisualBasicContentType)>
    <Name(PredefinedCommandHandlerNames.Commit)>
    <Order(Before:=PredefinedCommandHandlerNames.EndConstruct)>
    <Order(Before:=PredefinedCompletionNames.CompletionCommandHandler)>
    Friend Class CommitCommandHandler
        Implements IChainedCommandHandler(Of ReturnKeyCommandArgs)
        Implements IChainedCommandHandler(Of PasteCommandArgs)
        Implements IChainedCommandHandler(Of SaveCommandArgs)
        Implements IChainedCommandHandler(Of FormatDocumentCommandArgs)
        Implements IChainedCommandHandler(Of FormatSelectionCommandArgs)
 
        Private ReadOnly _bufferManagerFactory As CommitBufferManagerFactory
        Private ReadOnly _editorOperationsFactoryService As IEditorOperationsFactoryService
        Private ReadOnly _smartIndentationService As ISmartIndentationService
        Private ReadOnly _textUndoHistoryRegistry As ITextUndoHistoryRegistry
        Private ReadOnly _globalOptions As IGlobalOptionService
 
        Public ReadOnly Property DisplayName As String Implements INamed.DisplayName
            Get
                Return VBEditorResources.Line_commit
            End Get
        End Property
 
        <ImportingConstructor()>
        <SuppressMessage("RoslynDiagnosticsReliability", "RS0033:Importing constructor should be [Obsolete]", Justification:="Used in test code: https://github.com/dotnet/roslyn/issues/42814")>
        Public Sub New(
            bufferManagerFactory As CommitBufferManagerFactory,
            editorOperationsFactoryService As IEditorOperationsFactoryService,
            smartIndentationService As ISmartIndentationService,
            textUndoHistoryRegistry As ITextUndoHistoryRegistry,
            globalOptions As IGlobalOptionService)
 
            _bufferManagerFactory = bufferManagerFactory
            _editorOperationsFactoryService = editorOperationsFactoryService
            _smartIndentationService = smartIndentationService
            _textUndoHistoryRegistry = textUndoHistoryRegistry
            _globalOptions = globalOptions
        End Sub
 
        Public Sub ExecuteCommand(args As FormatDocumentCommandArgs, nextHandler As Action, context As CommandExecutionContext) Implements IChainedCommandHandler(Of FormatDocumentCommandArgs).ExecuteCommand
            If Not args.SubjectBuffer.CanApplyChangeDocumentToWorkspace() Then
                nextHandler()
                Return
            End If
 
            Using context.OperationContext.AddScope(allowCancellation:=True, VBEditorResources.Formatting_Document)
                Dim buffer = args.SubjectBuffer
                Dim snapshot = buffer.CurrentSnapshot
 
                Dim wholeFile = snapshot.GetFullSpan()
                Dim commitBufferManager = _bufferManagerFactory.CreateForBuffer(buffer)
                commitBufferManager.ExpandDirtyRegion(wholeFile)
                commitBufferManager.CommitDirty(isExplicitFormat:=True, cancellationToken:=context.OperationContext.UserCancellationToken)
            End Using
        End Sub
 
        Public Function GetCommandState(args As FormatDocumentCommandArgs, nextHandler As Func(Of CommandState)) As CommandState Implements IChainedCommandHandler(Of FormatDocumentCommandArgs).GetCommandState
            Return nextHandler()
        End Function
 
        Public Sub ExecuteCommand(args As FormatSelectionCommandArgs, nextHandler As Action, context As CommandExecutionContext) Implements IChainedCommandHandler(Of FormatSelectionCommandArgs).ExecuteCommand
            If Not args.SubjectBuffer.CanApplyChangeDocumentToWorkspace() Then
                nextHandler()
                Return
            End If
 
            Using context.OperationContext.AddScope(allowCancellation:=True, VBEditorResources.Formatting_Document)
                Dim buffer = args.SubjectBuffer
                Dim selections = args.TextView.Selection.GetSnapshotSpansOnBuffer(buffer)
 
                If selections.Count < 1 Then
                    nextHandler()
                    Return
                End If
 
                Dim snapshot = buffer.CurrentSnapshot
                For index As Integer = 0 To selections.Count - 1
                    Dim textspan = CommonFormattingHelpers.GetFormattingSpan(snapshot, selections(0))
                    Dim selectedSpan = New SnapshotSpan(snapshot, textspan.Start, textspan.Length)
                    Dim commitBufferManager = _bufferManagerFactory.CreateForBuffer(buffer)
                    commitBufferManager.ExpandDirtyRegion(selectedSpan)
                    commitBufferManager.CommitDirty(isExplicitFormat:=True, cancellationToken:=context.OperationContext.UserCancellationToken)
                Next
            End Using
 
            'We don't call nextHandler, since we have handled this command.
        End Sub
 
        Public Function GetCommandState(args As FormatSelectionCommandArgs, nextHandler As Func(Of CommandState)) As CommandState Implements IChainedCommandHandler(Of FormatSelectionCommandArgs).GetCommandState
            Return nextHandler()
        End Function
 
        Public Sub ExecuteCommand(args As ReturnKeyCommandArgs, nextHandler As Action, context As CommandExecutionContext) Implements IChainedCommandHandler(Of ReturnKeyCommandArgs).ExecuteCommand
            If Not _globalOptions.GetOption(LineCommitOptionsStorage.PrettyListing, LanguageNames.VisualBasic) Then
                nextHandler()
                Return
            End If
 
            ' Commit is not cancellable.
            Dim _cancellationToken = CancellationToken.None
            Dim bufferManager = _bufferManagerFactory.CreateForBuffer(args.SubjectBuffer)
            Dim oldCaretPoint = args.TextView.GetCaretPoint(args.SubjectBuffer)
 
            ' When we call nextHandler(), it's possible that some other feature might try to move the caret
            ' or something similar. We want this "outer" commit to be the real one, so start suppressing any
            ' re-entrant commits.
            Dim suppressionHandle = bufferManager.BeginSuppressingCommits()
 
            Try
                ' Evil: we really want a enter in VB to be always grouped as a single undo transaction, and so make sure all
                ' things from here on out are grouped as one.
                Using transaction = _textUndoHistoryRegistry.GetHistory(args.TextView.TextBuffer).CreateTransaction(EditorFeaturesResources.Insert_new_line)
                    transaction.MergePolicy = AutomaticCodeChangeMergePolicy.Instance
 
                    nextHandler()
 
                    If ShouldCommitFromEnter(oldCaretPoint, args.TextView, args.SubjectBuffer, _cancellationToken) Then
                        ' We are done suppressing at this point
                        suppressionHandle.Dispose()
                        suppressionHandle = Nothing
 
                        bufferManager.CommitDirty(isExplicitFormat:=False, cancellationToken:=_cancellationToken)
 
                        ' We may have re-indented the surrounding block, so let's recompute
                        ' where we should end up
                        Dim newCaretPosition = args.TextView.GetCaretPoint(args.SubjectBuffer)
 
                        If newCaretPosition.HasValue Then
                            Dim currentLine = newCaretPosition.Value.GetContainingLine()
                            Dim desiredIndentation = args.TextView.GetDesiredIndentation(_smartIndentationService, currentLine)
                            If currentLine.Length = 0 AndAlso desiredIndentation.HasValue Then
                                args.TextView.TryMoveCaretToAndEnsureVisible(New VirtualSnapshotPoint(currentLine.Start, desiredIndentation.Value))
                                _editorOperationsFactoryService.GetEditorOperations(args.TextView).AddAfterTextBufferChangePrimitive()
                            End If
                        End If
                    End If
 
                    transaction.Complete()
                End Using
            Finally
                ' Resume committing
                If suppressionHandle IsNot Nothing Then
                    suppressionHandle.Dispose()
                End If
            End Try
        End Sub
 
        Private Function ShouldCommitFromEnter(
            oldCaretPositionInOldSnapshot As SnapshotPoint?,
            textView As ITextView,
            subjectBuffer As ITextBuffer,
            cancellationToken As CancellationToken) As Boolean
 
            Dim newCaretPosition = textView.GetCaretPoint(subjectBuffer)
 
            If Not oldCaretPositionInOldSnapshot.HasValue OrElse Not newCaretPosition.HasValue Then
                ' We somehow moved in or out of our subject buffer during this commit. Not sure how,
                ' but that counts as losing focus and thus is a commit
                Return True
            End If
 
            ' Map oldCaretPosition forward to the current snapshot
            Dim oldCaretPositionInCurrentSnapshot = oldCaretPositionInOldSnapshot.Value.CreateTrackingPoint(PointTrackingMode.Negative).GetPoint(subjectBuffer.CurrentSnapshot)
            Dim bufferManager = _bufferManagerFactory.CreateForBuffer(subjectBuffer)
 
            If CommitBufferManager.IsMovementBetweenStatements(oldCaretPositionInCurrentSnapshot, newCaretPosition.Value, cancellationToken) Then
                Dim document = subjectBuffer.CurrentSnapshot.GetOpenDocumentInCurrentContextWithChanges()
                If document Is Nothing Then
                    Return False
                End If
 
                Dim tree = document.GetSyntaxTreeSynchronously(cancellationToken)
                Dim token = tree.FindTokenOnLeftOfPosition(oldCaretPositionInOldSnapshot.Value, cancellationToken)
 
                If token.IsKind(SyntaxKind.StringLiteralToken) AndAlso token.FullSpan.Contains(oldCaretPositionInOldSnapshot.Value) Then
                    Return False
                End If
 
                ' Get the statement which we pressed enter for
                Dim oldStatement = ContainingStatementInfo.GetInfo(oldCaretPositionInCurrentSnapshot, tree, cancellationToken)
 
                Return oldStatement Is Nothing OrElse Not oldStatement.IsIncomplete
            End If
 
            Return False
        End Function
 
        Public Function GetCommandState(args As ReturnKeyCommandArgs, nextHandler As Func(Of CommandState)) As CommandState Implements IChainedCommandHandler(Of ReturnKeyCommandArgs).GetCommandState
            ' We don't make any decision if the enter key is allowed; we just forward onto the next handler
            Return nextHandler()
        End Function
 
        Public Sub ExecuteCommand(args As PasteCommandArgs, nextHandler As Action, context As CommandExecutionContext) Implements IChainedCommandHandler(Of PasteCommandArgs).ExecuteCommand
            Using context.OperationContext.AddScope(allowCancellation:=True, EditorFeaturesResources.Formatting_pasted_text)
                CommitOnPaste(args, nextHandler, context.OperationContext.UserCancellationToken)
            End Using
        End Sub
 
        Private Sub CommitOnPaste(args As PasteCommandArgs, nextHandler As Action, cancellationToken As CancellationToken)
            Using transaction = _textUndoHistoryRegistry.GetHistory(args.TextView.TextBuffer).CreateTransaction(EditorFeaturesResources.Paste)
                Dim oldVersion = args.SubjectBuffer.CurrentSnapshot.Version
 
                ' Do the paste in the same transaction as the commit/format
                nextHandler()
 
                If Not _globalOptions.GetOption(FormattingOptionsStorage.FormatOnPaste, LanguageNames.VisualBasic) Then
                    transaction.Complete()
                    Return
                End If
 
                Dim document = args.SubjectBuffer.CurrentSnapshot.GetOpenDocumentInCurrentContextWithChanges()
                If document IsNot Nothing Then
                    Dim formattingRuleService = document.Project.Solution.Services.GetService(Of IHostDependentFormattingRuleFactoryService)()
                    If formattingRuleService.ShouldNotFormatOrCommitOnPaste(document.Id) Then
                        transaction.Complete()
                        Return
                    End If
                End If
 
                ' Did we paste content that changed the number of lines?
                If oldVersion.Changes IsNot Nothing AndAlso oldVersion.Changes.IncludesLineChanges Then
                    Try
                        _bufferManagerFactory.CreateForBuffer(args.SubjectBuffer).CommitDirty(isExplicitFormat:=False, cancellationToken:=cancellationToken)
                    Catch ex As OperationCanceledException
                        ' If the commit was cancelled, we still want the paste to go through
                    End Try
                End If
 
                transaction.Complete()
            End Using
        End Sub
 
        Public Function GetCommandState(args As PasteCommandArgs, nextHandler As Func(Of CommandState)) As CommandState Implements IChainedCommandHandler(Of PasteCommandArgs).GetCommandState
            Return nextHandler()
        End Function
 
        Public Sub ExecuteCommand(args As SaveCommandArgs, nextHandler As Action, context As CommandExecutionContext) Implements IChainedCommandHandler(Of SaveCommandArgs).ExecuteCommand
            If _globalOptions.GetOption(FormattingOptionsStorage.FormatOnSave) Then
                Using context.OperationContext.AddScope(allowCancellation:=True, VBEditorResources.Formatting_Document)
                    Using transaction = _textUndoHistoryRegistry.GetHistory(args.TextView.TextBuffer).CreateTransaction(VBEditorResources.Format_on_Save)
                        _bufferManagerFactory.CreateForBuffer(args.SubjectBuffer).CommitDirty(isExplicitFormat:=False, cancellationToken:=context.OperationContext.UserCancellationToken)
 
                        ' We should only create the transaction if anything actually happened
                        If transaction.UndoPrimitives.Any() Then
                            transaction.Complete()
                        End If
                    End Using
                End Using
            End If
 
            nextHandler()
        End Sub
 
        Public Function GetCommandState(args As SaveCommandArgs, nextHandler As Func(Of CommandState)) As CommandState Implements IChainedCommandHandler(Of SaveCommandArgs).GetCommandState
            Return nextHandler()
        End Function
    End Class
End Namespace