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EuHigorBarbosa/main.dart

Last active December 1, 2022 10:42
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Stream in several pages
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main.dart
import 'package:flutter/material.dart';
import 'dart:async';
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(
routes: {
'/pageA': (context) => const PageAA(),
'/pageB': (context) => const PageBB(),
'/pageC': (context) => const PageCC()
},
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const PageAA(),
);
}
}
class PageAA extends StatefulWidget {
const PageAA({Key? key}) : super(key: key);
@override
State<PageAA> createState() => _PageAAState();
}
class _PageAAState extends State<PageAA> {
@override
Widget build(BuildContext context) {
return LayoutBuilder(builder: (context, constraints) {
return Container(
//decoration: BackGroundImage.BackGroundImageBoxDecoration,
child: Scaffold(
appBar: AppBar(title: const Text('Page A')),
//backgroundColor: Colors.transparent,
body: Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
const Center(
child: Text(
'Start the program in page C',
style: TextStyle(
color: Colors.black,
fontSize: 20,
),
),
),
IconButton(
icon: const Icon(Icons.arrow_forward_ios),
onPressed: () => Navigator.of(context).pushNamed('/pageB'),
)
],
),
),
),
);
});
}
}
class PageBB extends StatefulWidget {
const PageBB({Key? key}) : super(key: key);
@override
State<PageBB> createState() => _PageBBState();
}
class _PageBBState extends State<PageBB> {
SeqDepService seqDepService = SeqDepService();
@override
Widget build(BuildContext context) {
return LayoutBuilder(builder: (context, constraints) {
return Container(
//decoration: BackGroundImage.BackGroundImageBoxDecoration,
child: Scaffold(
appBar: AppBar(title: Text('Page B')),
//backgroundColor: Colors.transparent,
body: Padding(
padding: const EdgeInsets.symmetric(horizontal: 18.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: [
Center(child: Text('StreamBuilder with Connection State\n\nWait 4 seconds',textAlign: TextAlign.center, style: TextStyle( color: Colors.red, fontSize: 20))),
Center(child: StreamBuilder<List<SeqDepEntity>>(
initialData: seqDepService.activeSeqDepList,
stream: seqDepService.activeSeqDepListStream,
builder: ((context, snapshot) {
if(snapshot.connectionState == ConnectionState.none){
return Center(child: (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15))));
}
if(snapshot.connectionState == ConnectionState.waiting){
return Column(
children: [
Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)),
CircularProgressIndicator(),
],
);
}
if(snapshot.connectionState == ConnectionState.done){
return Center(child: (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15))));
}
if(snapshot.connectionState == ConnectionState.active){
return Center(child: (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15))));
}
return Container();
})),),
SizedBox(height: 40,),
Center(child: Text('StreamBuilder with hasData and hasError',textAlign: TextAlign.center, style: TextStyle(color: Colors.red, fontSize: 20))),
Center(child: StreamBuilder<List<SeqDepEntity>>(
initialData: seqDepService.activeSeqDepList,
stream: seqDepService.activeSeqDepListStream,
builder: ((context, snapshot) {
if(snapshot.hasData){
return (Text('last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)));
} if (snapshot.hasError) {
return Text('If has error the StreamBuilder show up error');
}
else {
return Container();
}
})),),
SizedBox(height: 50,),
Center(child: Text('Look the Stream in page C too', style: TextStyle(color: Colors.black, fontSize: 15))),
IconButton(icon: Icon(Icons.arrow_forward_ios), onPressed: ()=>Navigator.of(context).pushNamed('/pageC'),)
],
),
),
),
);
});
}
}
class PageCC extends StatefulWidget {
const PageCC({Key? key}) : super(key: key);
@override
State<PageCC> createState() => _PageCCState();
}
class _PageCCState extends State<PageCC> {
SeqDepService seqDepService = SeqDepService();
@override
Widget build(BuildContext context) {
return LayoutBuilder(builder: (context, constraints) {
return Container(
//decoration: BackGroundImage.BackGroundImageBoxDecoration,
child: Scaffold(
appBar: AppBar(title: Text('Page C')),
//backgroundColor: Colors.transparent,
body: Padding(
padding: const EdgeInsets.symmetric(horizontal: 18.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
//crossAxisAlignment: CrossAxisAlignment.center,
children: [
Center(child: Text('StreamBuilder with Connection State\n\nWait 4 seconds',textAlign: TextAlign.center, style: TextStyle(color: Colors.red, fontSize: 20))),
Center(
child: StreamBuilder<List<SeqDepEntity>>(
initialData: (seqDepService.activeSeqDepList.length>0)?seqDepService.activeSeqDepList:[],
stream: seqDepService.activeSeqDepListStream,
builder: ((context, snapshot) {
if(snapshot.connectionState == ConnectionState.none){
return (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)));
}
if(snapshot.connectionState == ConnectionState.waiting){
return Column(
children: [
Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)),
CircularProgressIndicator(),
],
);
}
if(snapshot.connectionState == ConnectionState.done){
return (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)));
}
if(snapshot.connectionState == ConnectionState.active){
return (Text(' ${snapshot.connectionState} \n last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)));
}
return Container();
})),
),
SizedBox(height: 40,),
Center(child: Text('StreamBuilder with hasData and hasError',textAlign: TextAlign.center, style: TextStyle(color: Colors.red, fontSize: 20))),
Center(child: StreamBuilder<List<SeqDepEntity>>(
initialData: seqDepService.activeSeqDepList,
stream: seqDepService.activeSeqDepListStream,
builder: ((context, snapshot) {
if(snapshot.hasData){
return (Text('last Snapshot data is: ${snapshot.data!.length}', style: TextStyle(color: Colors.black, fontSize: 15)));
} if (snapshot.hasError) {
return Text('If has error the StreamBuilder show up error');
}
else {
return Container();
}
})),),
//Center(child: IconButton(icon: Icon(Icons.add,size: 30, color: Colors.blue,), onPressed: ()=>seqDepService.addActiveSeqDep(SeqDepEntity(id:'unique', content:1)),))
],
),
),
),
);
});
}
}
class SeqDepEntity {
String id;
int content;
SeqDepEntity({
required this.id,
required this.content,
});
}
abstract class SeqDepService {
List<SeqDepEntity> get activeSeqDepList;
Stream<List<SeqDepEntity>> get activeSeqDepListStream;
/// Add a single item on stream data. The stream data is a List<SeqDepEntity>
//addActiveSeqDep( SeqDepEntity entity);
factory SeqDepService() {
return SeqDepServiceFFmpeg();
}
}
class SeqDepServiceFFmpeg implements SeqDepService {
static SeqDepServiceFFmpeg? _instance;
SeqDepServiceFFmpeg._();
factory SeqDepServiceFFmpeg(){
_instance ??= SeqDepServiceFFmpeg._();
return _instance!;
}
static List<SeqDepEntity> _activeListSeqDep = [];
static var timer = Timer(Duration(seconds: 0), (){});
static MultiStreamController<List<SeqDepEntity>>? _multiController;
static final StreamController<List<SeqDepEntity>> _controller = StreamController<List<SeqDepEntity>>.broadcast(
onListen: () async{
for(int i = 0; i<5; i++){
await Future.delayed(Duration(seconds: 4));
_activeListSeqDep.add(SeqDepEntity(content: i, id: 'id'+i.toString()));
_addInStream(_activeListSeqDep);
}
}
);
@override
List<SeqDepEntity> get activeSeqDepList => _activeListSeqDep;
@override
Stream<List<SeqDepEntity>> get activeSeqDepListStream => _controller.stream;//_activeMultiSeqDepStream;//
// @override
// void addActiveSeqDep( SeqDepEntity seqDep) {
// _activeListSeqDep.add(seqDep);
// _addInStream(_activeListSeqDep);
// }
static void _addInStream (List<SeqDepEntity> activeEntities){
_controller.sink.add(activeEntities);
}
}
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