notify_state

Description:

notify state

notify_state #

State sharing management of business objects.

Using #

use NotifyObject with ChangeNotifier
use StatefulWidget extends NotifyWidget
use State extends NotifyState

class TestWidget extends NotifyWidget {
TestWidget({Key key, @required ChangeNotifier notifier}):super(key: key, notifier:notifier);
@override
_TestWidgetState createState() => new _TestWidgetState();
}

class _TestWidgetState extends NotifyState {
}
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demo:

import 'package:flutter/material.dart';

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

class TestNotify with ChangeNotifier {
num _counter = 0;
num get counter => _counter;
set counter(num v) {
_counter = v;
notifyListeners();
}
}

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: HomePage(
title: 'Flutter Demo',
data: new TestNotify(),
),
);
}
}

class HomePage extends StatefulWidget {
HomePage({Key key, this.title, this.data}) : super(key: key);

final TestNotify data;
final String title;

@override
_HomePageState createState() => new _HomePageState();
}

class _HomePageState extends State<HomePage> {
TestNotify data;
@override
void initState() {
super.initState();
this.data = widget.data;
}

void _incrementCounter() {
data.counter++;
}

@override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new TestWidget(notifier:data),
floatingActionButton: new FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: new Icon(Icons.add),
),
);
}
}

class TestWidget extends NotifyWidget {
TestWidget({Key key, @required ChangeNotifier notifier}):super(key: key, notifier:notifier);
@override
_TestWidgetState createState() => new _TestWidgetState();
}

class _TestWidgetState extends NotifyState {
@override
Widget build(BuildContext context) {
return new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Text(
'You have pushed the button this many times:',
),
new Text(
'${(notifier as TestNotify).counter}',
style: Theme.of(context).textTheme.display1,
),
],
),
);
}
}

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