private void Start(CancellationToken cancellationToken)
{
// this is where the caret should go after the change
SnapshotPoint pos = TextView.Caret.Position.BufferPosition;
ITrackingPoint beforeTrackingPoint = pos.Snapshot.CreateTrackingPoint(pos.Position, PointTrackingMode.Negative);
ITextSnapshot snapshot = SubjectBuffer.CurrentSnapshot;
SnapshotPoint closingSnapshotPoint = ClosingPoint.GetPoint(snapshot);
if (closingSnapshotPoint.Position < 1)
{
Debug.Fail("The closing point was not found at the expected position.");
EndSession();
return;
}
SnapshotPoint openingSnapshotPoint = closingSnapshotPoint.Subtract(1);
if (openingSnapshotPoint.GetChar() != OpeningBrace)
{
// there is a bug in editor brace completion engine on projection buffer that already fixed in vs_pro. until that is FIed to use
// I will make this not to assert
// Debug.Fail("The opening brace was not found at the expected position.");
EndSession();
return;
}
OpeningPoint = snapshot.CreateTrackingPoint(openingSnapshotPoint, PointTrackingMode.Positive);
var document = snapshot.GetOpenDocumentInCurrentContextWithChanges();
if (!_session.CheckOpeningPoint(this, cancellationToken))
{
EndSession();
return;
}
using (ITextUndoTransaction undo = CreateUndoTransaction())
{
// insert the closing brace
using (ITextEdit edit = SubjectBuffer.CreateEdit())
{
edit.Insert(closingSnapshotPoint, ClosingBrace.ToString());
if (edit.HasFailedChanges)
{
Debug.Fail("Unable to insert closing brace");
// exit without setting the closing point which will take us off the stack
edit.Cancel();
undo.Cancel();
return;
}
else
{
snapshot = edit.Apply();
}
}
SnapshotPoint beforePoint = beforeTrackingPoint.GetPoint(TextView.TextSnapshot);
// switch from positive to negative tracking so it stays against the closing brace
ClosingPoint = SubjectBuffer.CurrentSnapshot.CreateTrackingPoint(ClosingPoint.GetPoint(snapshot), PointTrackingMode.Negative);
Debug.Assert(ClosingPoint.GetPoint(snapshot).Position > 0 && (new SnapshotSpan(ClosingPoint.GetPoint(snapshot).Subtract(1), 1))
.GetText().Equals(ClosingBrace.ToString()), "The closing point does not match the closing brace character");
// move the caret back between the braces
TextView.Caret.MoveTo(beforePoint);
_session.AfterStart(this, cancellationToken);
undo.Complete();
}
}
