content: import 'package:flutter/material.dart';
  import 'package:url_launcher/url_launcher.dart';
  
  class Day83InteractiveViewer extends StatefulWidget {
    Day83InteractiveViewer({Key key}) : super(key: key);
  
    @override
    _Day83InteractiveViewerState createState() => _Day83InteractiveViewerState();
  }
  
  class _Day83InteractiveViewerState extends State<Day83InteractiveViewer> {
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        body: Center(
          // ? What is InteractiveViewer....
          // ! InteractiveViewer is the cool widget added in flutter 1.20....
          // here we can get full interaction on the widgets....
          child: InteractiveViewer(
            boundaryMargin: EdgeInsets.all(20.0),
            minScale: 0.1,
            maxScale: 1.6,
            child: Container(
              decoration: BoxDecoration(
                gradient: LinearGradient(
                  begin: Alignment.topCenter,
                  end: Alignment.bottomCenter,
                  colors: <Color>[Colors.orange, Colors.red],
                  stops: <double>[0.0, 1.0],
                ),
              ),
            ),
          ),
        ),
        appBar: AppBar(
          title: Text('InteractiveViewer'),
          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/day083_interactive_viewer.dart';
                if (await canLaunch(url)) {
                  await launch(url);
                } else {
                  throw 'Could not launch $url';
                }
              },
            )
          ],
        ),
      );
    }
  }
  