Manage scrolling for SingleChildScrollView inside a SingleChildScrollView - flutter?

Question

I have a parent SCS View(SingleChildScrollView) and a child SCS View. Inside the child SCS View there is a Data Table, and the Data Table starts at around bottom quarter of the screen.

Now, I want to scroll the parent SCS View when the user scrolls to the top of Data Table inside child SCS View.

This works naturally in web, but does not work in iOS or anroid. I tried using same Scrollcontroller for both parent & child SCS View and played around with ScrollPhysics. But nothing seem to work. Can you please help me with a solution.

Here is the code:

    import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Report'),
        ),
      ),
    ),
  );
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final ScrollController scrollController = ScrollController();

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      child: Column(
        children: [
          Text('Some Data', style: TextStyle(fontSize: 30)),
          Text('Some Data', style: TextStyle(fontSize: 30)),
          Text('Some Data', style: TextStyle(fontSize: 30)),
          Text('Some Data', style: TextStyle(fontSize: 30)),
          Text('Some Data', style: TextStyle(fontSize: 30)),
          Text('Some Data', style: TextStyle(fontSize: 30)),
          ConstrainedBox(
            constraints: BoxConstraints(
              maxHeight: 400,
            ),
            child: Scrollbar(
              controller: scrollController,
              child: SingleChildScrollView(
                controller: scrollController,
                child: SingleChildScrollView(
                  scrollDirection: Axis.horizontal,
                  child: DataTable(
                    columns: [
                      DataColumn(label: Text('Sl. No.')),
                      DataColumn(label: Text('Resource Name')),
                      DataColumn(label: Text('Score at 1')),
                      DataColumn(label: Text('Score at 2')),
                      DataColumn(label: Text('Final Score')),
                    ],
                    rows: [
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                      DataRow(
                        cells: [
                          DataCell(Text('1')),
                          DataCell(Text('Person 1')),
                          DataCell(Text('5')),
                          DataCell(Text('2')),
                          DataCell(Text('8')),
                        ],
                      ),
                    ],
                  ),
                ),
              ),
            ),
          )
        ],
      ),
    );
  }
}

Thank you.

Answer 1

You can use NotificationListener to listen OverscrollNotification to detect the upper boundary hit of the nested list and scroll to the outer Scrollview by controlling it.

I simplify your problem to a example code below:

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

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

class _MyNestedListViewState extends State<MyNestedListView> {
  final _controller = ScrollController();

  @override
  Widget build(BuildContext context) {
    return ListView(
      controller: _controller,
      children: [
        Placeholder(fallbackHeight: 400),
        Placeholder(fallbackHeight: 400),
        Placeholder(fallbackHeight: 400),
        Container(
          padding: EdgeInsets.symmetric(horizontal: 20),
          height: 400,
          child: NotificationListener(
            onNotification: (notification) {
              // disable overscroll indicator
              // if (notification is OverscrollIndicatorNotification) {
              //   if (notification.leading) {
              //     notification.disallowGlow();
              //   }
              // }
              if (notification is OverscrollNotification) {
                final dy = notification.overscroll;
                if (dy < 0) {
                  _controller.position.jumpTo(_controller.offset + dy);
                }
              }
              return true;
            },
            child: ListView(
              children: [
                Placeholder(fallbackHeight: 200),
                Placeholder(fallbackHeight: 200),
                Placeholder(fallbackHeight: 200),
                Placeholder(fallbackHeight: 200),
              ],
            ),
          ),
        )
      ],
    );
  }

  @override
  void dispose() {
    super.dispose();
    _controller.dispose();
  }
}