Usage

easy loader widget to handle future data

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import 'package:flutter/material.dart';
import 'package:loader_widget/loader_widget.dart';

void main() {
runApp(const MyApp());
}

class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);

@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}

class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);

final String title;

@override
State<MyHomePage> createState() => \_MyHomePageState();
}

class \_MyHomePageState extends State<MyHomePage> {
final controller = StateController<String>();
final loaderController = StateController<String>();

@override
void initState() {
super.initState();
\_loadingData();
}

Future<void> \_loadingData() async {
const data = 'hi';
try {
for (var i = 0; i <= 10; i++) {
controller.loading(progress: i.toDouble());
await Future.delayed(const Duration(seconds: 1));
}
if (data.isEmpty) {
return controller.empty();
}
controller.finished(data);
} catch (e) {
controller.error(e);
}
}

Future<String> \_loaderData() async {
const data = 'hi';
for (var i = 5; i <= 10; i++) {
loaderController.loading(progress: i.toDouble());
await Future.delayed(const Duration(seconds: 1));
}
if (data.isEmpty) {
loaderController.empty();
return '';
}
return data;
}

@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Column(
children: [
LoaderWidget<String>(
stateController: controller,
emptyWidget: () {
return const SizedBox.shrink();
},
errorWidget: (e) {
return Text(e.toString());
},
loadingWidget: (progress) {
return Stack(
children: [
Positioned(
top: 10,
bottom: 0,
left: 0,
right: 0,
child: Text(
progress.toString(),
textAlign: TextAlign.center,
softWrap: true,
),
),
const CircularProgressIndicator.adaptive(),
],
);
},
finishedWidget: (result) {
return Text(result.toString());
},
),
const Divider(),
LoaderWidget<String>(
stateController: loaderController,
loader: \_loaderData,
emptyWidget: () {
return const SizedBox.shrink();
},
errorWidget: (e) {
return Text(e.toString());
},
loadingWidget: (progress) {
return Stack(
children: [
Positioned(
top: 10,
bottom: 0,
left: 0,
right: 0,
child: Text(
progress.toString(),
textAlign: TextAlign.center,
softWrap: true,
),
),
const CircularProgressIndicator.adaptive(),
],
);
},
finishedWidget: (result) {
return Text(result.toString());
},
),
],
),
);
}
}