internal static AnalysisResult InvokesPropertyChangedFor(this SyntaxNode assignment, IPropertySymbol property, SemanticModel semanticModel, CancellationToken cancellationToken)
{
var invokes = AnalysisResult.No;
var block = assignment.FirstAncestorOrSelf <MethodDeclarationSyntax>()?.Body ??
assignment.FirstAncestorOrSelf <AccessorDeclarationSyntax>()?.Body ??
assignment.FirstAncestorOrSelf <AnonymousFunctionExpressionSyntax>()?.Body;
if (block == null)
{
return(AnalysisResult.No);
}
using (var pooled = InvocationWalker.Create(block))
{
foreach (var invocation in pooled.Item.Invocations)
{
if (invocation.SpanStart < assignment.SpanStart)
{
continue;
}
switch (TryGetInvokedPropertyChangedName(invocation, semanticModel, cancellationToken, out ArgumentSyntax _, out string propertyName))
{
internal static bool TryGetInvoker(ITypeSymbol type, SemanticModel semanticModel, CancellationToken cancellationToken, out IMethodSymbol invoker)
{
invoker = null;
foreach (var member in type.GetMembers())
{
var method = member as IMethodSymbol;
if (method?.Parameters.Length != 1)
{
continue;
}
var parameter = method.Parameters[0];
if (method.DeclaringSyntaxReferences.Length == 0)
{
if (parameter.Type == KnownSymbol.String &&
method.Name.Contains("PropertyChnaged"))
{
// A bit speculative here
// for handling the case when inheriting a ViewModelBase class from a binary reference.
invoker = method;
}
continue;
}
foreach (var declaration in method.Declarations(cancellationToken))
{
using (var pooled = InvocationWalker.Create(declaration))
{
foreach (var invocation in pooled.Item.Invocations)
{
var invokedMethod = semanticModel.GetSymbolSafe(invocation, cancellationToken) as IMethodSymbol;
if (invokedMethod == null)
{
continue;
}
if (invokedMethod == KnownSymbol.PropertyChangedEventHandler.Invoke)
{
ArgumentSyntax argument;
if (invocation.ArgumentList.Arguments.TryGetAtIndex(1, out argument))
{
var identifier = argument.Expression as IdentifierNameSyntax;
if (identifier?.Identifier.ValueText == parameter.Name)
{
invoker = method;
return(true);
}
var objectCreation = argument.Expression as ObjectCreationExpressionSyntax;
if (objectCreation != null)
{
var nameArgument = objectCreation.ArgumentList.Arguments[0];
if ((nameArgument.Expression as IdentifierNameSyntax)?.Identifier.ValueText == parameter.Name)
{
invoker = method;
return(true);
}
}
}
}
}
}
}
}
return(invoker != null);
}
internal static InvokesPropertyChanged InvokesPropertyChangedFor(this AssignmentExpressionSyntax assignment, IPropertySymbol property, SemanticModel semanticModel, CancellationToken cancellationToken)
{
var invokes = InvokesPropertyChanged.No;
var block = assignment.FirstAncestorOrSelf <BlockSyntax>();
if (block == null)
{
return(InvokesPropertyChanged.No);
}
using (var pooled = InvocationWalker.Create(block))
{
foreach (var invocation in pooled.Item.Invocations)
{
if (invocation.SpanStart < assignment.SpanStart)
{
continue;
}
var method = semanticModel.GetSymbolSafe(invocation, cancellationToken) as IMethodSymbol;
if (method == null)
{
continue;
}
if (method == KnownSymbol.PropertyChangedEventHandler.Invoke)
{
ArgumentSyntax argument;
if (invocation.ArgumentList.Arguments.TryGetAtIndex(1, out argument))
{
if (argument.Expression.IsCreatePropertyChangedEventArgsFor(property, semanticModel, cancellationToken))
{
return(InvokesPropertyChanged.Yes);
}
var cached = semanticModel.GetSymbolSafe(argument.Expression, cancellationToken);
if (cached is IFieldSymbol)
{
foreach (var syntaxReference in cached.DeclaringSyntaxReferences)
{
var declarator = syntaxReference.GetSyntax(cancellationToken) as VariableDeclaratorSyntax;
if (declarator?.Initializer?.Value?.IsCreatePropertyChangedEventArgsFor(property, semanticModel, cancellationToken) == true)
{
return(InvokesPropertyChanged.Yes);
}
}
}
continue;
}
}
switch (method.InvokesPropertyChangedFor(property, invocation, semanticModel, cancellationToken))
{
case InvokesPropertyChanged.No:
break;
case InvokesPropertyChanged.Yes:
return(InvokesPropertyChanged.Yes);
case InvokesPropertyChanged.Maybe:
if (invokes == InvokesPropertyChanged.No)
{
invokes = InvokesPropertyChanged.Maybe;
}
break;
default:
throw new ArgumentOutOfRangeException();
}
}
}
return(invokes);
}