How to sync scroll two SingleChildScrollView widgets

like xster said, you have to use scrollcontroller on one scrollview and notification Listener on another scrollview, here is the code.

class StackO extends StatefulWidget {  // const stack({Key key}) : super(key: key);  @override  _StackOState createState() => _StackOState();}class _StackOState extends State<StackO> {  ScrollController _scrollController = new ScrollController();  @override  Widget build(BuildContext context) {    return Container(      child: Column(        children: <Widget>[          new Positioned(            child: new SingleChildScrollView(              controller: _scrollController,              scrollDirection: Axis.horizontal,              child: new Scale() // your widgets,            ),          ),          new Positioned(            child: new NotificationListener<ScrollNotification>(              onNotification: (ScrollNotification scrollInfo) {                print('scrolling.... ${scrollInfo.metrics.pixels}');                _scrollController.jumpTo(scrollInfo.metrics.pixels);                return false;              },              child: SingleChildScrollView(                scrollDirection: Axis.horizontal,                child: new chart() // your widgets,              ),            ),          ),        ],      ),    );  }}

For input, you control them via a ScrollController passed in as a constructor parameter.

For output, you can use a NotificationListener to listen to movements on one and then use the ScrollController to sync them together.

You can either listen to something like https://docs.flutter.io/flutter/widgets/UserScrollNotification-class.html to keep them tightly bound or wait for https://docs.flutter.io/flutter/widgets/ScrollEndNotification-class.html and then call https://docs.flutter.io/flutter/widgets/ScrollController/animateTo.html on the ScrollController.