setState hold focus and keyboard visibility - flutter

Question

I tried to create something like the textfield widget in the gif below. I listen to the controller for changes and call setState(). I choose between two widgets depending on the controller.text.isEmpty. The problem is whenever setState is called the textField loses focus and the keyboard disappears. How do I stop this from happening?
Widget textInputInactive = Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
children: [
IconButton(onPressed: () {}, icon: Icon(Icons.camera_alt, size: 28, color: Color(0xff99999A),)),
IconButton(onPressed: () {}, icon: Icon(Icons.upload_file, size: 28, color: Color(0xff99999A),)),
Expanded(
child: textField
),
],
),
);
Widget textInputActive = Padding(
padding: const EdgeInsets.all(8.0),
child: Row(
children: [
Expanded(child: textField),
IconButton(onPressed: () {}, icon: Icon(Icons.send, color: Color(0xff99999A)))
],
),
);
Widget currTextInput = _textController.text.isNotEmpty ? textInputActive : textInputInactive;

Answer 1

If you need the keyboard to gain focus after the setState method is called. You need to create a focus node object and initialize it in your initState, and add it as a parameter to your focus node in the textfield. Then after you call setState, request focus, here is an example below.
class MyWidget extends StatefulWidget {
const MyWidget({super.key});
#override
State<MyWidget> createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
// create the FocusNode object
FocusNode node = FocusNode();
#override
void initState() {
super.initState();
// request focus of the textfield
node.requestFocus();
}
#override
void dispose() {
// disposing it
node.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
// assume this is where you call your setState
// to call back focus on the textfield
setState(() {});
node.requestFocus();
return TextField(
// add the node object here
focusNode: node,
);
}
}

Answer 2

You can try to use Value Notifier instead of setState, since setState will render the whole page and create a new focus node. check this link for value notifier and use it only for text filed