/// <summary>
/// Inserts 'newUsing' in the current scope.
/// This method will try to insert new usings in the correct position (depending on
/// where the existing usings are; and maintaining the sort order).
/// </summary>
public static void InsertUsing(RefactoringContext context, Script script, AstNode newUsing)
{
UsingInfo newUsingInfo = new UsingInfo(newUsing, context);
AstNode enclosingNamespace = context.GetNode <NamespaceDeclaration>() ?? context.RootNode;
// Find nearest enclosing parent that has usings:
AstNode usingParent = enclosingNamespace;
while (usingParent != null && !usingParent.Children.OfType <UsingDeclaration>().Any())
{
usingParent = usingParent.Parent;
}
if (usingParent == null)
{
// No existing usings at all -> use the default location
if (script.FormattingOptions.UsingPlacement == UsingPlacement.TopOfFile)
{
usingParent = context.RootNode;
}
else
{
usingParent = enclosingNamespace;
}
}
// Find the main block of using declarations in the chosen scope:
AstNode blockStart = usingParent.Children.FirstOrDefault(IsUsingDeclaration);
AstNode insertionPoint;
bool insertAfter = false;
if (blockStart == null)
{
// no using declarations in the file
Debug.Assert(SyntaxTree.MemberRole == NamespaceDeclaration.MemberRole);
insertionPoint = usingParent.GetChildrenByRole(SyntaxTree.MemberRole).SkipWhile(CanAppearBeforeUsings).FirstOrDefault();
}
else
{
insertionPoint = blockStart;
while (IsUsingFollowing(ref insertionPoint) && newUsingInfo.CompareTo(new UsingInfo(insertionPoint, context)) > 0)
{
insertionPoint = insertionPoint.NextSibling;
}
if (!IsUsingDeclaration(insertionPoint))
{
// Insert after last using instead of before next node
// This affects where empty lines get placed.
insertionPoint = insertionPoint.PrevSibling;
insertAfter = true;
}
}
if (insertionPoint != null)
{
if (insertAfter)
{
script.InsertAfter(insertionPoint, newUsing);
}
else
{
script.InsertBefore(insertionPoint, newUsing);
}
}
}
