/// <summary>
/// creates a new class declaration where members are delegated to the mixin
/// reference
/// </summary>
/// <param name="classDeclaration"></param>
/// <returns></returns>
public override SyntaxNode VisitClassDeclaration(ClassDeclarationSyntax classDeclaration)
{
var mixinName = _mixin.Name;
// currently, only three types of member forwardings are possible,
// there is a strategy for every forwarding implementation
var implementationStrategies = CreateStrategies(_mixin, _semantic, _settings);
// needed to evaluate whether type names can be reduced (depends on the using statements in the file)
var positionOfClassInSourceFile = classDeclaration.GetLocation().SourceSpan.Start;
// generate the members that should be implemented
var membersToAdd = _members
.Select(x => implementationStrategies[x.GetType()].ImplementMember(x, positionOfClassInSourceFile))
.Where(x => x != null).ToArray();
// add regions if there is something to generate
if (_settings.CreateRegions)
{
var regionCaption = $" mixin {mixinName}";
// if there is already a region, add members to this one,
// otherwise create a new one
if (classDeclaration.HasRegion(regionCaption))
return classDeclaration.AddMembersIntoRegion(regionCaption, membersToAdd);
else
membersToAdd.AddRegionAround(regionCaption);
}
// return a new class node with the additional members
// problem with AddMembers is that it adds the new code
// after the last syntax node, so when a region exists in the class
// the code will be added before the region end, this leads to the bug
// https://github.com/pgenfer/mixinSharp/issues/9
// where the newly created region is nested into the old one.
// a solution is to ensure that the members are added after any endregion directive
// check if there is an end region in the file
var lastEndRegion = classDeclaration.GetLastElementInClass<EndRegionDirectiveTriviaSyntax>();
// only interesting if there is an end region directive at all
if(lastEndRegion != null)
{
var lastSyntaxNode = classDeclaration.GetLastElementInClass<SyntaxNode>(false);
if (lastSyntaxNode != lastEndRegion && lastSyntaxNode.SpanStart < lastEndRegion.Span.End)
{
// special case here: there is an end region directive at the end of the class
// so we must add our members AFTER this endregion (by removing it and adding it before the first member)
if (membersToAdd.Length > 0)
{
var newClassDeclaration = classDeclaration.RemoveNode(lastEndRegion, SyntaxRemoveOptions.AddElasticMarker);
membersToAdd[0] = membersToAdd[0].WithLeadingTrivia(
new SyntaxTriviaList()
.Add(Trivia(EndRegionDirectiveTrivia(true)))
.Add(EndOfLine(NewLine))
.AddRange(membersToAdd[0].GetLeadingTrivia()));
return newClassDeclaration.AddMembers(membersToAdd);
}
}
}
return classDeclaration.AddMembers(membersToAdd);
}
