public ITextUndoHistory RegisterHistory(object context) { ITextUndoHistory history; if (!_map.TryGetValue(context, out history)) { history = new TextUndoHistory(); _map.Add(context, history); } return history; }
public TextUndoTransaction(TextUndoHistory textUndoHistory, string description) { _textUndoHistory = textUndoHistory; Description = description; }