private void FilterImpl(string searchPattern)
{
var snapshot = _textBuffer.CurrentSnapshot;
var entrySpans = _history.GetAllHistoryEntrySpans();
Debug.Assert(entrySpans.Any());
var spansToShow = new List <Span>();
var spansToHide = new List <Span>();
var span = entrySpans[0];
var showSpan = _textSearchService.Find(span, span.Start, searchPattern, FindOptions.Multiline).HasValue;
for (var i = 1; i < entrySpans.Count; i++)
{
var nextSpan = entrySpans[i];
var showNextSpan = _textSearchService.Find(nextSpan, nextSpan.Start, searchPattern, FindOptions.Multiline).HasValue;
if (showNextSpan)
{
if (showSpan)
{
span = new SnapshotSpan(span.Start, nextSpan.End);
}
else if (spansToShow.Any())
{
spansToHide.Add(span);
span = new SnapshotSpan(span.End, nextSpan.End);
}
else
{
spansToHide.Add(new SnapshotSpan(span.Start, nextSpan.Start));
span = nextSpan;
}
showSpan = true;
}
else
{
if (!showSpan)
{
span = new SnapshotSpan(span.Start, nextSpan.End);
}
else
{
spansToShow.Add(span);
span = new SnapshotSpan(span.End, nextSpan.End);
}
showSpan = false;
}
}
// Add last span
if (showSpan)
{
spansToShow.Add(span);
}
else
{
spansToHide.Add(span);
}
if (spansToShow.Count == 0)
{
if (_elisionBuffer.CurrentSnapshot.Length == 0)
{
return;
}
_elisionBuffer.ModifySpans(new NormalizedSpanCollection(new Span(0, snapshot.Length)), new NormalizedSpanCollection(new Span(0, 0)));
return;
}
_elisionBuffer.ExpandSpans(new NormalizedSpanCollection(new Span(0, snapshot.Length)));
MoveCaretToVisiblePoint(spansToShow, snapshot);
if (spansToHide.Count != 0)
{
_elisionBuffer.ElideSpans(new NormalizedSpanCollection(spansToHide));
}
_textView.Caret.EnsureVisible();
}
