streambuilder is rebuilding again and again when keyboard popup or closes

Question

Here I was stuck in a problem. I have a column of widgets with a stream builder and a text field. When i try to input some text, the keyboard pops up and then the stream builder rebuilds again or when the keyboard closes, the stream builder rebuilds again. As i am building a chat screen, I don't want to rebuild the stream builder again as it increases in number of reads.

Any sort of suggestions helpful.

Answer 1

Flutter calls the build() method every time it wants to change anything in the view, and this happens surprisingly often.

You can pass the stream into the stateless widget

 MyApp({Key key, this.stream}) : super(key: key);

Or build the stream in the initState method if the widget is statefull.

@override
void initState() {
  super.initState();
  post = buildStream();
}

Answer 2

What @TuanNguyen means by

build the stream in the initState method

is the following, if for you are using Firestore for exemple:

class MyStateFullWidget extends StatefulWidget {
  const MyStateFullWidget({Key key}) : super(key: key);

  @override
  _MyStateFullWidgetState createState() => _MyStateFullWidgetState();
}

class _MyStateFullWidgetState extends State<MyStateFullWidget> {
  Stream _myStream;

  @override
  void initState() {
    super.initState();
    _myStream = FirebaseFirestore.instance.collection(myCollection) ... .snapshots();
  }

  @override
  Widget build(BuildContext context) {
    return SomeUpperWidget(
      child: 
      StreamBuilder(
        stream: _myStream,
        builder: (ctx, snap) => ... ,
      )
    );
  }
}