1. reflectable
void doPos(Event e, detail)

Source

@reflectable
void doPos(Event e,var detail) {
  DatePickerOverlay ov = $['pick'] as DatePickerOverlay;

  // Ok : let's position the damn thing.
  Rectangle r = ov.parent.getBoundingClientRect();
  var left = r.left;
  var top = r.top;

  ov.style.position = "fixed";
  ov.style.left="${left}px";
  ov.style.top="${top}px";

  // Inform the component of positioning style
  /*
  ov.jsElement[r'dimensions'][r'position'] = new js.JsObject.jsify({
      "h":"left",
      "v":"top"
  });*/
}