How to work with progress indicator in flutter?

Question

I\'m newbie in flutter and wanted to know what is better way to add CircularProgressIndicator in my layout. For example, my login view. This view have username,

Answer 1

1. Without plugin

    class IndiSampleState extends State {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        appBar: new AppBar(
          title: new Text('Demo'),
        ),
        body: Center(
          child: RaisedButton(
            color: Colors.blueAccent,
            child: Text('Login'),
            onPressed: () async {
              showDialog(
                  context: context,
                  builder: (BuildContext context) {
                    return Center(child: CircularProgressIndicator(),);
                  });
              await loginAction();
              Navigator.pop(context);
            },
          ),
        ));
  }

  Future loginAction() async {
    //replace the below line of code with your login request
    await new Future.delayed(const Duration(seconds: 2));
    return true;
  }
}

2. With plugin

check this plugin progress_hud

add the dependency in the pubspec.yaml file

dev_dependencies:
  progress_hud: 

import the package

import 'package:progress_hud/progress_hud.dart';

Sample code is given below to show and hide the indicator

class ProgHudPage extends StatefulWidget {
  @override
  _ProgHudPageState createState() => _ProgHudPageState();
}

class _ProgHudPageState extends State {
  ProgressHUD _progressHUD;
  @override
  void initState() {
    _progressHUD = new ProgressHUD(
      backgroundColor: Colors.black12,
      color: Colors.white,
      containerColor: Colors.blue,
      borderRadius: 5.0,
      loading: false,
      text: 'Loading...',
    );
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
        appBar: new AppBar(
          title: new Text('ProgressHUD Demo'),
        ),
        body: new Stack(
          children: [
            _progressHUD,
            new Positioned(
                child: RaisedButton(
                  color: Colors.blueAccent,
                  child: Text('Login'),
                  onPressed: () async{
                    _progressHUD.state.show();
                    await loginAction();
                    _progressHUD.state.dismiss();
                  },
                ),
                bottom: 30.0,
                right: 10.0)
          ],
        ));
  }

  Future loginAction()async{
    //replace the below line of code with your login request
    await new Future.delayed(const Duration(seconds: 2));
    return true;
  }
}