private void AddChange(ITextPointer startPosition, int symbolCount, PrecursorTextChangeType precursorTextChange)
{
Invariant.Assert(!_isReadOnly, "Illegal to modify DocumentSequenceTextContainer inside Change event scope!");
ITextContainer textContainer = (ITextContainer)this;
textContainer.BeginChange();
try
{
// Contact any listeners.
if (this.Changing != null)
{
Changing(this, EventArgs.Empty);
}
// Fire the ChangingEvent now if we haven't already.
if (_changes == null)
{
_changes = new TextContainerChangedEventArgs();
}
_changes.AddChange(precursorTextChange, DocumentSequenceTextPointer.GetOffsetToPosition(_start, startPosition), symbolCount, false /* collectTextChanges */);
if (this.Change != null)
{
Invariant.Assert(precursorTextChange == PrecursorTextChangeType.ContentAdded || precursorTextChange == PrecursorTextChangeType.ContentRemoved);
TextChangeType textChange = (precursorTextChange == PrecursorTextChangeType.ContentAdded) ?
TextChangeType.ContentAdded : TextChangeType.ContentRemoved;
_isReadOnly = true;
try
{
// Pass in a -1 for charCount parameter. DocumentSequenceTextContainer
// doesn't support this feature because it is only consumed by IMEs
// which never run on read-only documents.
Change(this, new TextContainerChangeEventArgs(startPosition, symbolCount, -1, textChange));
}
finally
{
_isReadOnly = false;
}
}
}
finally
{
textContainer.EndChange();
}
}