appointmentCanvas.setStyleName(CANVAS_STYLE);
selectedAppointmentWidgets.clear();
if (dragController == null) {
dragController = new MonthViewPickupDragController(appointmentCanvas, true);
dragController.addDragHandler(new DragHandler() {
public void onDragEnd(DragEndEvent event) {
Appointment appt = ((AppointmentWidget) event.getContext().draggable).getAppointment();