/// <summary>
/// Get the backing fields for the <paramref name="propertyDeclaration"/> these are different for readonly dependency properties where the setter returns the DependencyPropertyKey field.
/// </summary>
internal static bool TryGetBackingFields(PropertyDeclarationSyntax propertyDeclaration, SemanticModel semanticModel, CancellationToken cancellationToken, out BackingFieldOrProperty getField, out BackingFieldOrProperty setField)
{
getField = default;
setField = default;
if (propertyDeclaration.TryGetGetter(out var getAccessor) &&
propertyDeclaration.TryGetSetter(out var setAccessor))
{
using (var getterWalker = ClrGetterWalker.Borrow(semanticModel, cancellationToken, getAccessor))
{
using (var setterWalker = ClrSetterWalker.Borrow(semanticModel, cancellationToken, setAccessor))
{
if (getterWalker.HasError ||
setterWalker.HasError)
{
return(false);
}
if (getterWalker.IsSuccess &&
BackingFieldOrProperty.TryCreateForDependencyProperty(semanticModel.GetSymbolSafe(getterWalker.Property.Expression, cancellationToken), out getField) &&
setterWalker.IsSuccess &&
BackingFieldOrProperty.TryCreateForDependencyProperty(semanticModel.GetSymbolSafe(setterWalker.Property.Expression, cancellationToken), out setField))
{
return(true);
}
var property = semanticModel.GetSymbolSafe(propertyDeclaration, cancellationToken) as IPropertySymbol;
return(TryGetBackingFieldsByName(property, semanticModel.Compilation, out getField, out setField));
}
}
}
return(false);
}
internal static bool IsAttachedSet(MethodDeclarationSyntax method, SemanticModel semanticModel, CancellationToken cancellationToken, out InvocationExpressionSyntax setValueCall, out BackingFieldOrProperty setField)
{
setValueCall = null;
setField = default(BackingFieldOrProperty);
if (method == null ||
method.ParameterList.Parameters.Count != 2 ||
!method.ReturnType.IsVoid() ||
!method.Modifiers.Any(SyntaxKind.StaticKeyword))
{
return(false);
}
using (var walker = ClrSetterWalker.Borrow(semanticModel, cancellationToken, method))
{
if (!walker.IsSuccess)
{
return(false);
}
setValueCall = walker.SetValue ?? walker.SetCurrentValue;
if (setValueCall.Expression is MemberAccessExpressionSyntax memberAccess &&
memberAccess.IsKind(SyntaxKind.SimpleMemberAccessExpression) &&
memberAccess.Expression is IdentifierNameSyntax member)
{
if (method.ParameterList.Parameters[0].Identifier.ValueText != member.Identifier.ValueText)
{
return(false);
}
if (setValueCall.TryGetArgumentAtIndex(1, out var arg) &&
method.ParameterList.Parameters.TryElementAt(1, out var parameter))
{
if (arg.Expression is IdentifierNameSyntax argIdentifier &&
argIdentifier.Identifier.ValueText == parameter.Identifier.ValueText)
{
return(BackingFieldOrProperty.TryCreateForDependencyProperty(semanticModel.GetSymbolSafe(walker.Property.Expression, cancellationToken), out setField));
}
if (arg.Expression is InvocationExpressionSyntax invocation &&
invocation.TrySingleArgument(out var nestedArg) &&
nestedArg.Expression is IdentifierNameSyntax nestedArgId &&
nestedArgId.Identifier.ValueText == parameter.Identifier.ValueText)
{
return(BackingFieldOrProperty.TryCreateForDependencyProperty(semanticModel.GetSymbolSafe(walker.Property.Expression, cancellationToken), out setField));
}
if (arg.Expression is ConditionalExpressionSyntax ternary &&
ternary.Condition is IdentifierNameSyntax conditionIdentifier &&
conditionIdentifier.Identifier.ValueText == parameter.Identifier.ValueText)
{
return(BackingFieldOrProperty.TryCreateForDependencyProperty(semanticModel.GetSymbolSafe(walker.Property.Expression, cancellationToken), out setField));
}
}
}
return(false);
}
}
