private static void Handle(SyntaxNodeAnalysisContext context)
{
if (!context.IsExcludedFromAnalysis() &&
context.ContainingSymbol is INamedTypeSymbol type &&
type.IsAssignableToEither(KnownSymbol.IValueConverter, KnownSymbol.IMultiValueConverter, context.Compilation) &&
context.Node is ClassDeclarationSyntax classDeclaration &&
!type.IsAbstract &&
type.DeclaredAccessibility != Accessibility.Private &&
type.DeclaredAccessibility != Accessibility.Protected)
{
if (!type.IsAssignableTo(KnownSymbol.MarkupExtension, context.Compilation))
{
if (ValueConverter.TryGetDefaultFieldsOrProperties(type, context.Compilation, out var defaults))
{
foreach (var fieldOrProperty in defaults)
{
if (fieldOrProperty.TryGetAssignedValue(context.CancellationToken, out var assignedValue) &&
context.SemanticModel.TryGetType(assignedValue, context.CancellationToken, out var assignedType) &&
!Equals(assignedType, type))
{
context.ReportDiagnostic(Diagnostic.Create(WPF0074DefaultMemberOfWrongType.Descriptor, assignedValue.GetLocation()));
}
}
}
else if (!Virtual.HasVirtualOrAbstractOrProtectedMembers(type) &&
!type.Constructors.TryFirst(x => x.Parameters.Length > 0, out _) &&
!Mutable.HasMutableInstanceMembers(type))
{
context.ReportDiagnostic(Diagnostic.Create(WPF0070ConverterDoesNotHaveDefaultField.Descriptor, classDeclaration.Identifier.GetLocation()));
}
}
if (type.IsAssignableTo(KnownSymbol.IValueConverter, context.Compilation))
{
if (Attribute.TryFind(classDeclaration, KnownSymbol.ValueConversionAttribute, context.SemanticModel, context.CancellationToken, out var attribute))
{
if (ValueConverter.TryGetConversionTypes(classDeclaration, context.SemanticModel, context.CancellationToken, out var sourceType, out var targetType))
{
if (sourceType != null &&
sourceType != QualifiedType.System.Object &&
Attribute.TryFindArgument(attribute, 0, "sourceType", out var arg) &&
arg.Expression is TypeOfExpressionSyntax sourceTypeOf &&
TypeOf.TryGetType(sourceTypeOf, type, context.SemanticModel, context.CancellationToken, out var argType) &&
!Equals(argType, sourceType))
{
context.ReportDiagnostic(Diagnostic.Create(WPF0072ValueConversionMustUseCorrectTypes.Descriptor, arg.GetLocation(), sourceType));
}
if (Attribute.TryFindArgument(attribute, 1, "targetType", out arg) &&
arg.Expression is TypeOfExpressionSyntax targetTypeOf &&
TypeOf.TryGetType(targetTypeOf, type, context.SemanticModel, context.CancellationToken, out argType) &&
!Equals(argType, targetType))
{
context.ReportDiagnostic(Diagnostic.Create(WPF0072ValueConversionMustUseCorrectTypes.Descriptor, arg.GetLocation(), targetType));
}
}
}
else
{
if (ValueConverter.TryGetConversionTypes(classDeclaration, context.SemanticModel, context.CancellationToken, out _, out _))
{
context.ReportDiagnostic(Diagnostic.Create(WPF0071ConverterDoesNotHaveAttribute.Descriptor, classDeclaration.Identifier.GetLocation()));
}
else
{
context.ReportDiagnostic(Diagnostic.Create(WPF0073ConverterDoesNotHaveAttributeUnknownTypes.Descriptor, classDeclaration.Identifier.GetLocation()));
}
}
}
}
}