content: import 'package:flutter/material.dart';
  import 'package:url_launcher/url_launcher.dart';
  
  class Day80Padding extends StatefulWidget {
    const Day80Padding({Key key}) : super(key: key);
  
    @override
    _Day80PaddingState createState() => _Day80PaddingState();
  }
  
  class _Day80PaddingState extends State<Day80Padding> {
    static var all = const EdgeInsets.all(150.0); // EdgeInsets for all side.....
    static var only = const EdgeInsets.only(
      top: 250,
      bottom: 250,
    ); // EdgeInsets for top and bottom side....
    static var ltrb = EdgeInsets.fromLTRB(
        100, 100, 100, 100); // EdgeInsets for all side by LTRB....
    static var symmetric = EdgeInsets.symmetric(
        horizontal: 25,
        vertical: 50); // EdgeInsets for vertical and horizontal....
  
    var selected = [all, only, ltrb, symmetric];
    int index = 0;
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
        bottomNavigationBar: BottomNavigationBar(
          items: [
            BottomNavigationBarItem(icon: Icon(Icons.filter_1), label: "All"),
            BottomNavigationBarItem(icon: Icon(Icons.filter_2), label: "Only"),
            BottomNavigationBarItem(icon: Icon(Icons.filter_3), label: "LTRB"),
            BottomNavigationBarItem(
                icon: Icon(Icons.filter_4), label: "Symmertic"),
          ],
          currentIndex: index,
          onTap: (value) {
            setState(() {
              print(value);
              index = value;
            });
          },
          selectedItemColor: Colors.deepPurple,
          unselectedItemColor: Colors.deepPurple[100],
        ),
        body: SafeArea(
          // ? What is Padding....
          child: Padding(
            padding: selected[index], // ! You can add the EdgeInsets here....
            child: Container(
              width: double.infinity,
              height: double.infinity,
              color: Colors.deepOrange,
              child: Center(child: Text("${selected[index]}")),
            ),
          ),
        ),
        appBar: AppBar(
          title: Text('Padding'),
          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/day080_padding.dart';
                if (await canLaunch(url)) {
                  await launch(url);
                } else {
                  throw 'Could not launch $url';
                }
              },
            )
          ],
        ),
      );
    }
  }
  