public void RegisterTextDocument(ITextDocument document) { SendRegisterFileRequest(document.FilePath); // Add various event handlers var handlers = new TextDocumentEventHandlers { ChangedHandler = (s, e) => TextBufferOnChangedLowPriority(document, e), FileActionOccurred = FileActionOccurred, }; if (_documents.TryAdd(document, handlers)) { TextDocumentOnOpen(document, new EventArgs()); document.TextBuffer.ChangedLowPriority += handlers.ChangedHandler; document.FileActionOccurred += handlers.FileActionOccurred; } }