surf_storage 0.0.1-dev.5 surf_storage: ^0.0.1-dev.5 copied to clipboard
Based on LocalStorage data storage wrap, simple json storage.
// Copyright (c) 2019-present, SurfStudio LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
import 'dart:async';
import 'package:example/counter.dart';
import 'package:flutter/material.dart';
import 'package:surf_storage/base/storage.dart';
import 'package:surf_storage/impl/json_storage.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key key}) : super(key: key);
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key key, this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
static const _counterKey = 'counter';
Counter _currentValue;
StreamController<Counter> _counterController;
Stream<Counter> _counterStream;
final Storage _storage = JsonStorage('jsonStorageExample');
@override
void initState() {
super.initState();
_counterController = StreamController();
_counterStream = _counterController.stream;
_storage
.get(_counterKey)
// ignore: avoid_annotating_with_dynamic
.then((dynamic json) {
return json == null
? const Counter()
: Counter.fromJson(json as Map<String, Object>);
})
.then((counter) => _currentValue = counter)
.then(_counterController.add);
}
@override
void dispose() {
_counterController.close();
super.dispose();
}
void _incrementCounter() {
final newCounter = _currentValue.getIncremented();
_currentValue = newCounter;
_counterController.add(newCounter);
_storage.put(_counterKey, newCounter.toJson());
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wire frame for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
StreamBuilder<Counter>(
stream: _counterStream,
initialData: const Counter(),
builder: (context, snapshot) {
return Text(
'${snapshot.data.value}',
style: Theme.of(context).textTheme.headline4,
);
},
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}