protected override async Task<SignatureHelpItems> GetItemsWorkerAsync(Document document, int position, SignatureHelpTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
InvocationExpressionSyntax invocationExpression;
if (!TryGetInvocationExpression(root, position, document.GetLanguageService<ISyntaxFactsService>(), triggerInfo.TriggerReason, cancellationToken, out invocationExpression))
{
return null;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(invocationExpression, cancellationToken).ConfigureAwait(false);
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within == null)
{
return null;
}
// get the regular signature help items
var symbolDisplayService = document.Project.LanguageServices.GetService<ISymbolDisplayService>();
var methodGroup = semanticModel.GetMemberGroup(invocationExpression.Expression, cancellationToken)
.OfType<IMethodSymbol>()
.FilterToVisibleAndBrowsableSymbols(document.ShouldHideAdvancedMembers(), semanticModel.Compilation);
// try to bind to the actual method
var symbolInfo = semanticModel.GetSymbolInfo(invocationExpression, cancellationToken);
var matchedMethodSymbol = symbolInfo.Symbol as IMethodSymbol;
// if the symbol could be bound, replace that item in the symbol list
if (matchedMethodSymbol != null && matchedMethodSymbol.IsGenericMethod)
{
methodGroup = methodGroup.Select(m => matchedMethodSymbol.OriginalDefinition == m ? matchedMethodSymbol : m);
}
methodGroup = methodGroup.Sort(symbolDisplayService, semanticModel, invocationExpression.SpanStart);
var expressionType = semanticModel.GetTypeInfo(invocationExpression.Expression, cancellationToken).Type as INamedTypeSymbol;
var anonymousTypeDisplayService = document.Project.LanguageServices.GetService<IAnonymousTypeDisplayService>();
var documentationCommentFormattingService = document.Project.LanguageServices.GetService<IDocumentationCommentFormattingService>();
var textSpan = SignatureHelpUtilities.GetSignatureHelpSpan(invocationExpression.ArgumentList);
var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
if (methodGroup.Any())
{
return CreateSignatureHelpItems(
GetMethodGroupItems(invocationExpression, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormattingService, within, methodGroup, cancellationToken),
textSpan, GetCurrentArgumentState(root, position, syntaxFacts, textSpan, cancellationToken));
}
else if (expressionType != null && expressionType.TypeKind == TypeKind.Delegate)
{
return CreateSignatureHelpItems(
GetDelegateInvokeItems(invocationExpression, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormattingService, within, expressionType, cancellationToken),
textSpan, GetCurrentArgumentState(root, position, syntaxFacts, textSpan, cancellationToken));
}
else
{
return null;
}
}
protected override async Task<CompletionItem> GetBuilderAsync(Document document, int position, CompletionTriggerInfo triggerInfo, CancellationToken cancellationToken = default(CancellationToken))
{
if (triggerInfo.TriggerReason == CompletionTriggerReason.TypeCharCommand)
{
var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
if (triggerInfo.IsDebugger)
{
// Aggressive Intellisense in the debugger: always show the builder
return CreateEmptyBuilder(text, position);
}
var tree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
var token = tree
.FindTokenOnLeftOfPosition(position, cancellationToken)
.GetPreviousTokenIfTouchingWord(position);
if (token.Kind() == SyntaxKind.None)
{
return null;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(token.Parent, cancellationToken).ConfigureAwait(false);
var typeInferrer = document.GetLanguageService<ITypeInferenceService>();
if (IsLambdaExpression(semanticModel, position, token, typeInferrer, cancellationToken))
{
return CreateBuilder(text, position, CSharpFeaturesResources.LambdaExpression, CSharpFeaturesResources.AutoselectDisabledDueToPotentialLambdaDeclaration);
}
else if (IsAnonymousObjectCreation(token))
{
return CreateBuilder(text, position, CSharpFeaturesResources.MemberName, CSharpFeaturesResources.AutoselectDisabledDueToPossibleExplicitlyNamesAnonTypeMemCreation);
}
else if (token.IsPreProcessorExpressionContext())
{
return CreateEmptyBuilder(text, position);
}
else if (IsImplicitArrayCreation(semanticModel, token, position, typeInferrer, cancellationToken))
{
return CreateBuilder(text, position, CSharpFeaturesResources.ImplicitArrayCreation, CSharpFeaturesResources.AutoselectDisabledDueToPotentialImplicitArray);
}
else if (token.IsKindOrHasMatchingText(SyntaxKind.FromKeyword) || token.IsKindOrHasMatchingText(SyntaxKind.JoinKeyword))
{
return CreateBuilder(text, position, CSharpFeaturesResources.RangeVariable, CSharpFeaturesResources.AutoselectDisabledDueToPotentialRangeVariableDecl);
}
}
return null;
}
protected override async Task<CompletionItem> GetSuggestionModeItemAsync(Document document, int position, TextSpan itemSpan, CompletionTrigger trigger, CancellationToken cancellationToken = default(CancellationToken))
{
if (trigger.Kind == CompletionTriggerKind.Insertion)
{
var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
var tree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
var token = tree
.FindTokenOnLeftOfPosition(position, cancellationToken)
.GetPreviousTokenIfTouchingWord(position);
if (token.Kind() == SyntaxKind.None)
{
return null;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(token.Parent, cancellationToken).ConfigureAwait(false);
var typeInferrer = document.GetLanguageService<ITypeInferenceService>();
if (IsLambdaExpression(semanticModel, position, token, typeInferrer, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.LambdaExpression, itemSpan, CSharpFeaturesResources.AutoselectDisabledDueToPotentialLambdaDeclaration);
}
else if (IsAnonymousObjectCreation(token) || IsPossibleTupleExpression(token))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.MemberName, itemSpan, CSharpFeaturesResources.AutoselectDisabledDueToPossibleExplicitlyNamesAnonTypeMemCreation);
}
else if (token.IsPreProcessorExpressionContext())
{
return CreateEmptySuggestionModeItem(itemSpan);
}
else if (IsImplicitArrayCreation(semanticModel, token, position, typeInferrer, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.ImplicitArrayCreation, itemSpan, CSharpFeaturesResources.AutoselectDisabledDueToPotentialImplicitArray);
}
else if (token.IsKindOrHasMatchingText(SyntaxKind.FromKeyword) || token.IsKindOrHasMatchingText(SyntaxKind.JoinKeyword))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.RangeVariable, itemSpan, CSharpFeaturesResources.AutoselectDisabledDueToPotentialRangeVariableDecl);
}
else if (tree.IsNamespaceDeclarationNameContext(position, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.NamespaceName, itemSpan, CSharpFeaturesResources.AutoselectDisabledDueToNamespaceDeclaration);
}
}
return null;
}
protected override async Task<SignatureHelpItems> GetItemsWorkerAsync(Document document, int position, SignatureHelpTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
AttributeSyntax attribute;
if (!TryGetAttributeExpression(root, position, document.GetLanguageService<ISyntaxFactsService>(), triggerInfo.TriggerReason, cancellationToken, out attribute))
{
return null;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(attribute, cancellationToken).ConfigureAwait(false);
var attributeType = semanticModel.GetTypeInfo(attribute, cancellationToken).Type as INamedTypeSymbol;
if (attributeType == null)
{
return null;
}
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within == null)
{
return null;
}
var symbolDisplayService = document.Project.LanguageServices.GetService<ISymbolDisplayService>();
var accessibleConstructors = attributeType.InstanceConstructors
.WhereAsArray(c => c.IsAccessibleWithin(within))
.FilterToVisibleAndBrowsableSymbols(document.ShouldHideAdvancedMembers(), semanticModel.Compilation)
.Sort(symbolDisplayService, semanticModel, attribute.SpanStart);
if (!accessibleConstructors.Any())
{
return null;
}
var anonymousTypeDisplayService = document.Project.LanguageServices.GetService<IAnonymousTypeDisplayService>();
var documentationCommentFormatter = document.Project.LanguageServices.GetService<IDocumentationCommentFormattingService>();
var textSpan = SignatureHelpUtilities.GetSignatureHelpSpan(attribute.ArgumentList);
var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
return CreateSignatureHelpItems(accessibleConstructors.Select(c =>
Convert(c, within, attribute, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormatter, cancellationToken)).ToList(),
textSpan, GetCurrentArgumentState(root, position, syntaxFacts, textSpan, cancellationToken));
}
protected override async Task<CompletionItem> GetSuggestionModeItemAsync(
Document document, int position, TextSpan itemSpan, CompletionTrigger trigger, CancellationToken cancellationToken = default(CancellationToken))
{
if (trigger.Kind == CompletionTriggerKind.Insertion)
{
var text = await document.GetTextAsync(cancellationToken).ConfigureAwait(false);
var tree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
var token = tree
.FindTokenOnLeftOfPosition(position, cancellationToken)
.GetPreviousTokenIfTouchingWord(position);
if (token.Kind() == SyntaxKind.None)
{
return null;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(token.Parent, cancellationToken).ConfigureAwait(false);
var typeInferrer = document.GetLanguageService<ITypeInferenceService>();
if (IsLambdaExpression(semanticModel, position, token, typeInferrer, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.lambda_expression, CSharpFeaturesResources.Autoselect_disabled_due_to_potential_lambda_declaration);
}
else if (IsAnonymousObjectCreation(token))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.member_name, CSharpFeaturesResources.Autoselect_disabled_due_to_possible_explicitly_named_anonymous_type_member_creation);
}
else if (token.IsPreProcessorExpressionContext())
{
return CreateEmptySuggestionModeItem();
}
else if (IsImplicitArrayCreation(semanticModel, token, position, typeInferrer, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.implicit_array_creation, CSharpFeaturesResources.Autoselect_disabled_due_to_potential_implicit_array_creation);
}
else if (token.IsKindOrHasMatchingText(SyntaxKind.FromKeyword) || token.IsKindOrHasMatchingText(SyntaxKind.JoinKeyword))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.range_variable, CSharpFeaturesResources.Autoselect_disabled_due_to_potential_range_variable_declaration);
}
else if (tree.IsNamespaceDeclarationNameContext(position, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.namespace_name, CSharpFeaturesResources.Autoselect_disabled_due_to_namespace_declaration);
}
else if (tree.IsPartialTypeDeclarationNameContext(position, cancellationToken, out var typeDeclaration))
{
switch (typeDeclaration.Keyword.Kind())
{
case SyntaxKind.ClassKeyword:
return CreateSuggestionModeItem(CSharpFeaturesResources.class_name, CSharpFeaturesResources.Autoselect_disabled_due_to_type_declaration);
case SyntaxKind.StructKeyword:
return CreateSuggestionModeItem(CSharpFeaturesResources.struct_name, CSharpFeaturesResources.Autoselect_disabled_due_to_type_declaration);
case SyntaxKind.InterfaceKeyword:
return CreateSuggestionModeItem(CSharpFeaturesResources.interface_name, CSharpFeaturesResources.Autoselect_disabled_due_to_type_declaration);
}
}
else if (tree.IsPossibleDeconstructionDesignation(position, cancellationToken))
{
return CreateSuggestionModeItem(CSharpFeaturesResources.designation_name,
CSharpFeaturesResources.Autoselect_disabled_due_to_possible_deconstruction_declaration);
}
}
return null;
}
protected override async Task<IEnumerable<CompletionItem>> GetItemsWorkerAsync(
Document document, int position, CompletionTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
var syntaxTree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
if (syntaxTree.IsInNonUserCode(position, cancellationToken))
{
return null;
}
var token = syntaxTree.FindTokenOnLeftOfPosition(position, cancellationToken);
token = token.GetPreviousTokenIfTouchingWord(position);
if (token.Kind() != SyntaxKind.OpenParenToken && token.Kind() != SyntaxKind.CommaToken)
{
return null;
}
var attributeArgumentList = token.Parent as AttributeArgumentListSyntax;
var attributeSyntax = token.Parent.Parent as AttributeSyntax;
if (attributeSyntax == null || attributeArgumentList == null)
{
return null;
}
// We actually want to collect two sets of named parameters to present the user. The
// normal named parameters that come from the attribute constructors. These will be
// presented like "foo:". And also the named parameters that come from the writable
// fields/properties in the attribute. These will be presented like "bar =".
var existingNamedParameters = GetExistingNamedParameters(attributeArgumentList, position);
var workspace = document.Project.Solution.Workspace;
var semanticModel = await document.GetSemanticModelForNodeAsync(attributeSyntax, cancellationToken).ConfigureAwait(false);
var nameColonItems = await GetNameColonItemsAsync(workspace, semanticModel, position, token, attributeSyntax, existingNamedParameters, cancellationToken).ConfigureAwait(false);
var nameEqualsItems = await GetNameEqualsItemsAsync(workspace, semanticModel, position, token, attributeSyntax, existingNamedParameters, cancellationToken).ConfigureAwait(false);
// If we're after a name= parameter, then we only want to show name= parameters.
if (IsAfterNameEqualsArgument(token))
{
return nameEqualsItems;
}
return nameColonItems.Concat(nameEqualsItems);
}
protected override async Task<bool> IsExclusiveAsync(Document document, int position, CompletionTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
// We're exclusive if this context could only be an object initializer and not also a
// collection initializer. If we're initializing something that could be initialized as
// an object or as a collection, say we're not exclusive. That way the rest of
// intellisense can be used in the collection intializer.
//
// Consider this case:
// class c : IEnumerable<int>
// {
// public void Add(int addend) { }
// public int foo;
// }
// void foo()
// {
// var b = new c {|
// }
// There we could initialize b using either an object initializer or a collection
// initializer. Since we don't know which the user will use, we'll be non-exclusive, so
// the other providers can help the user write the collection initializer, if they want
// to.
var tree = await document.GetSyntaxTreeAsync(cancellationToken).ConfigureAwait(false);
if (tree.IsInNonUserCode(position, cancellationToken))
{
return false;
}
var token = tree.FindTokenOnLeftOfPosition(position, cancellationToken);
token = token.GetPreviousTokenIfTouchingWord(position);
if (token.Parent == null)
{
return false;
}
var expression = token.Parent.Parent as ExpressionSyntax;
if (expression == null)
{
return false;
}
var semanticModel = await document.GetSemanticModelForNodeAsync(expression, cancellationToken).ConfigureAwait(false);
var initializedType = semanticModel.GetTypeInfo(expression, cancellationToken).Type;
if (initializedType == null)
{
return false;
}
// Non-exclusive if initializedType can be initialized as a collection.
if (initializedType.CanSupportCollectionInitializer())
{
return false;
}
// By default, only our member names will show up.
return true;
}
public static Task <SemanticModel> GetCSharpSemanticModelForNodeAsync(this Document document, SyntaxNode node, CancellationToken cancellationToken = default(CancellationToken))
{
return(document.GetSemanticModelForNodeAsync(node, cancellationToken));
}
protected override async Task<SignatureHelpItems> GetItemsWorkerAsync(Document document, int position, SignatureHelpTriggerInfo triggerInfo, CancellationToken cancellationToken)
{
var root = await document.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
SyntaxToken genericIdentifier, lessThanToken;
if (!TryGetGenericIdentifier(root, position, document.GetLanguageService<ISyntaxFactsService>(), triggerInfo.TriggerReason, cancellationToken,
out genericIdentifier, out lessThanToken))
{
return null;
}
var simpleName = genericIdentifier.Parent as SimpleNameSyntax;
if (simpleName == null)
{
return null;
}
var beforeDotExpression = simpleName.IsRightSideOfDot() ? simpleName.GetLeftSideOfDot() : null;
var semanticModel = await document.GetSemanticModelForNodeAsync(simpleName, cancellationToken).ConfigureAwait(false);
var leftSymbol = beforeDotExpression == null
? null
: semanticModel.GetSymbolInfo(beforeDotExpression, cancellationToken).GetAnySymbol() as INamespaceOrTypeSymbol;
var leftType = beforeDotExpression == null
? null
: semanticModel.GetTypeInfo(beforeDotExpression, cancellationToken).Type as INamespaceOrTypeSymbol;
var leftContainer = leftSymbol ?? leftType;
var isBaseAccess = beforeDotExpression is BaseExpressionSyntax;
var namespacesOrTypesOnly = SyntaxFacts.IsInNamespaceOrTypeContext(simpleName);
var includeExtensions = leftSymbol == null && leftType != null;
var name = genericIdentifier.ValueText;
var symbols = isBaseAccess
? semanticModel.LookupBaseMembers(position, name)
: namespacesOrTypesOnly
? semanticModel.LookupNamespacesAndTypes(position, leftContainer, name)
: semanticModel.LookupSymbols(position, leftContainer, name, includeExtensions);
var within = semanticModel.GetEnclosingNamedTypeOrAssembly(position, cancellationToken);
if (within == null)
{
return null;
}
var symbolDisplayService = document.Project.LanguageServices.GetService<ISymbolDisplayService>();
var accessibleSymbols =
symbols.Where(s => s.GetArity() > 0)
.Where(s => s is INamedTypeSymbol || s is IMethodSymbol)
.FilterToVisibleAndBrowsableSymbols(document.ShouldHideAdvancedMembers(), semanticModel.Compilation)
.Sort(symbolDisplayService, semanticModel, genericIdentifier.SpanStart);
if (!accessibleSymbols.Any())
{
return null;
}
var anonymousTypeDisplayService = document.Project.LanguageServices.GetService<IAnonymousTypeDisplayService>();
var documentationCommentFormattingService = document.Project.LanguageServices.GetService<IDocumentationCommentFormattingService>();
var textSpan = GetTextSpan(genericIdentifier, lessThanToken);
var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
return CreateSignatureHelpItems(accessibleSymbols.Select(s =>
Convert(s, lessThanToken, semanticModel, symbolDisplayService, anonymousTypeDisplayService, documentationCommentFormattingService, cancellationToken)).ToList(),
textSpan, GetCurrentArgumentState(root, position, syntaxFacts, textSpan, cancellationToken));
}
private async Task<ValueTuple<SemanticModel, IList<ISymbol>>> BindTokenAsync(
Document document,
SyntaxToken token,
CancellationToken cancellationToken)
{
var semanticModel = await document.GetSemanticModelForNodeAsync(token.Parent, cancellationToken).ConfigureAwait(false);
var enclosingType = semanticModel.GetEnclosingNamedType(token.SpanStart, cancellationToken);
var symbols = semanticModel.GetSymbols(token, document.Project.Solution.Workspace, bindLiteralsToUnderlyingType: true, cancellationToken: cancellationToken);
var bindableParent = document.GetLanguageService<ISyntaxFactsService>().GetBindableParent(token);
var overloads = semanticModel.GetMemberGroup(bindableParent, cancellationToken);
symbols = symbols.Where(IsOk)
.Where(s => IsAccessible(s, enclosingType))
.Concat(overloads)
.Distinct(SymbolEquivalenceComparer.Instance);
if (symbols.Any())
{
var typeParameter = symbols.First() as ITypeParameterSymbol;
return new ValueTuple<SemanticModel, IList<ISymbol>>(
semanticModel,
typeParameter != null && typeParameter.TypeParameterKind == TypeParameterKind.Cref
? SpecializedCollections.EmptyList<ISymbol>()
: symbols.ToList());
}
// Couldn't bind the token to specific symbols. If it's an operator, see if we can at
// least bind it to a type.
var syntaxFacts = document.Project.LanguageServices.GetService<ISyntaxFactsService>();
if (syntaxFacts.IsOperator(token))
{
var typeInfo = semanticModel.GetTypeInfo(token.Parent, cancellationToken);
if (IsOk(typeInfo.Type))
{
return new ValueTuple<SemanticModel, IList<ISymbol>>(semanticModel, new List<ISymbol>(1) { typeInfo.Type });
}
}
return ValueTuple.Create(semanticModel, SpecializedCollections.EmptyList<ISymbol>());
}