/// <summary>
/// Gets the range of the expression to the left of our starting span.
/// </summary>
/// <param name="nesting">1 if we have an opening parenthesis for sig completion</param>
/// <param name="paramIndex">The current parameter index.</param>
/// <returns></returns>
public SnapshotSpan?GetExpressionRange(int nesting, out int paramIndex, out SnapshotPoint?sigStart, bool forCompletion = true)
{
SnapshotSpan?start = null;
var endText = String.Empty;
paramIndex = 0;
sigStart = null;
bool nestingChanged = false;
ClassificationSpan lastToken = null;
// Walks backwards over all the lines
if (Tokens.Count > 0)
{
lastToken = Tokens[Tokens.Count - 1];
while (true)
{
// Walk backwards over the tokens in the current line
for (int t = Tokens.Count - 1; t >= 0; t--)
{
var token = Tokens[t];
var text = token.Span.GetText();
if (token.ClassificationType == Classifier.Provider.Keyword ||
(token.ClassificationType == Classifier.Provider.Operator &&
text != "[" && text != "]" && text != "}" && text != "{"))
{
if (nesting == 0)
{
if (start == null)
{
// hovering directly over a keyword, don't provide a tooltip
return(null);
}
else if ((nestingChanged || forCompletion) && token.ClassificationType == Classifier.Provider.Keyword && text == "def")
{
return(null);
}
break;
}
}
else if (token.ClassificationType == Classifier.Provider.OpenGroupingClassification || text == "[" || text == "{")
{
if (nesting != 0)
{
nesting--;
nestingChanged = true;
if (nesting == 0 && sigStart == null)
{
sigStart = token.Span.Start;
}
}
else
{
break;
}
}
else if (token.ClassificationType == Classifier.Provider.CloseGroupingClassification ||
text == "]" || text == "}")
{
nesting++;
nestingChanged = true;
}
else if (token.ClassificationType == Classifier.Provider.CommaClassification)
{
if (nesting == 0)
{
if (start == null)
{
return(null);
}
break;
}
else if (nesting == 1 && sigStart == null)
{
paramIndex++;
}
}
else if (token.ClassificationType == Classifier.Provider.Comment)
{
return(null);
}
start = token.Span;
}
if (nesting == 0 || CurrentLine.LineNumber == 0)
{
break;
}
// We're in a nested paren context, continue to the next line
// to capture the entire expression
endText = CurrentLine.GetText() + endText;
CurrentLine = Snapshot.GetLineFromLineNumber(CurrentLine.LineNumber - 1);
var classSpan = new SnapshotSpan(Snapshot, CurrentLine.Start, CurrentLine.Length);
Tokens = Classifier.GetClassificationSpans(classSpan);
}
}
if (start.HasValue)
{
return(new SnapshotSpan(
Snapshot,
new Span(
start.Value.Start.Position,
//_span.GetEndPoint(_snapshot).Position - start.Value.Start.Position
lastToken.Span.End.Position - start.Value.Start.Position
)
));
}
return(_span.GetSpan(_snapshot));
}