update method
Call this during State.didUpdateWidget() if your state's widget has a controller or focusNode.
Also call it during State.initState() if these values weren't passed to the constructor.
If text
is passed, it will become the (given or current) controller's
text unless it matches the controller's initial value.
Implementation
void update({
TextEditingController? controller,
FocusNode? focusNode,
String? text,
}) {
_updateController(controller, text);
_updateFocusNode(focusNode);
}