internal override ReadOnlyCollection <SnapshotSpan> MapReplacementSpanToSourceSnapshots(Span replacementSpan, ITextBuffer excludedBuffer)
{
// This is exactly like ordinary span mapping, except that empty source spans at the ends of the replacementSpan are included.
FrugalList <SnapshotSpan> mappedSpans = new FrugalList <SnapshotSpan>();
int rover = FindLowestSpanIndexOfPosition(replacementSpan.Start);
int roverHi = FindHighestSpanIndexOfPosition(replacementSpan.End);
// sourceSpans[rover] contains span.Start
SnapshotSpan sourceSpan = this.sourceSpans[rover];
{
SnapshotPoint mappedStart = sourceSpan.Start + (replacementSpan.Start - this.cumulativeLengths[rover]);
int mappedLength = mappedStart.Position + replacementSpan.Length < sourceSpan.End ? replacementSpan.Length : sourceSpan.End.Position - mappedStart;
SnapshotSpan mappedSpan = new SnapshotSpan(mappedStart, mappedLength);
if (mappedSpan.Length > 0 || mappedSpan.Snapshot.TextBuffer != excludedBuffer)
{
mappedSpans.Add(new SnapshotSpan(mappedStart, mappedLength));
}
}
// walk forward until we cover the entire span
while (rover < roverHi)
{
rover++;
sourceSpan = this.sourceSpans[rover];
SnapshotSpan mappedSpan = replacementSpan.End >= this.cumulativeLengths[rover + 1]
? sourceSpan
: new SnapshotSpan(sourceSpan.Snapshot, new Span(sourceSpan.Start, replacementSpan.End - this.cumulativeLengths[rover]));
if (mappedSpan.Length > 0 || mappedSpan.Snapshot.TextBuffer != excludedBuffer)
{
mappedSpans.Add(mappedSpan);
}
}
Debug.Assert(replacementSpan.Length == mappedSpans.Sum((SnapshotSpan s) => s.Length), "Inconsistency in MapReplacementSpanToSourceSnapshots");
return(new ReadOnlyCollection <SnapshotSpan>(mappedSpans));
}