content: import 'package:flutter/material.dart';
  import 'package:url_launcher/url_launcher.dart';
  
  class Day60DraggableScrollableSheet extends StatefulWidget {
    Day60DraggableScrollableSheet({Key key}) : super(key: key);
  
    @override
    _Day60DraggableScrollableSheetState createState() =>
        _Day60DraggableScrollableSheetState();
  }
  
  class _Day60DraggableScrollableSheetState
      extends State<Day60DraggableScrollableSheet> {
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: Container(
          // ? What is DraggableScrollableSheet....
          child: Stack(
            fit: StackFit.expand,
            children: <Widget>[
              Container(
                child: Align(
                  alignment: Alignment.topCenter,
                  child: Text(
                    "This is BackSide",
                    textAlign: TextAlign.center,
                    style: TextStyle(fontSize: 30),
                  ),
                ),
              ),
              DraggableScrollableSheet(
                /**
                 * ! DraggableScrollableSheet is the cool widget which widely used in the mobiles....
                 * ! when a bottm sheet is drag lead to scrollable list....
                 */
                expand: true, // ! weather the builder item fill the space....
                initialChildSize:
                    0.10, // ! intial size when the page is loaded or reloaded....
                maxChildSize: 0.90, // ! max size with the sheet is scroll up....
                minChildSize:
                    0.10, // ! min size with the sheet is scroll down....
                builder:
                    // ! here the list item is build with context and scroll controller....
                    (BuildContext context, ScrollController scrollController) {
                  return Container(
                    color: Colors.blue[100],
                    child: ListView.builder(
                      // ! to showcase the scroll function we added the listview here....
                      controller:
                          scrollController, // ! added the parent scroll controller here....
                      itemCount: 20,
                      itemBuilder: (BuildContext context, int index) {
                        return ListTile(title: Text('Item ${index + 1}'));
                      },
                    ),
                  );
                },
              ),
            ],
          ),
        ),
        appBar: AppBar(
          title: Text('DraggableScrollableSheet'),
          actions: <Widget>[
            IconButton(
              icon: Icon(Icons.help),
              onPressed: () async {
                const url =
                    'https://github.com/sanjaysanju618/100-Days-Of-Flutter-Widgets/' +
                        'blob/master/hundred_days_of_flutter_widget/' +
                        'lib/day060_draggable_scrollable_sheet.dart';
                if (await canLaunch(url)) {
                  await launch(url);
                } else {
                  throw 'Could not launch $url';
                }
              },
            )
          ],
        ),
      );
    }
  }
  