Animated moveable list in flutter? - flutter

any tips or help how can I make this on tap moveable list in flutter?
https://files.fm/f/txdn29dg3

The provided component is exactly what CupertinoPicker could offer you.
Also, as suggested in the documentation, you should combine the CupertinoPicker with showCupertinoModalPopup to display the picker modally at the bottom of the screen.
This is how the code could look like:
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(
scaffoldBackgroundColor: darkBlue,
),
debugShowCheckedModeBanner: false,
home: const Scaffold(
body: Center(
child: PickerPage(),
),
),
);
}
}
class PickerPage extends StatefulWidget {
const PickerPage();
#override
_PickerPageState createState() => _PickerPageState();
}
class _PickerPageState extends State<PickerPage> {
final _items = [
'Flat Rate',
'Hourly',
'Request for Price',
];
int _selectedItem = 0;
void _onSelectedItemChanged(int value) => setState(
() => _selectedItem = value,
);
void _showPicker() {
showCupertinoModalPopup(
context: context,
builder: (_) => PickerExample(
items: _items,
selectedItem: _selectedItem,
onSelectedItemChanged: _onSelectedItemChanged,
),
);
}
#override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Text(_items[_selectedItem]),
const SizedBox(height: 10.0),
ElevatedButton(
child: const Text('Show picker'),
onPressed: _showPicker,
),
],
);
}
}
class PickerExample extends StatefulWidget {
final List<String> items;
final int selectedItem;
final ValueSetter<int> onSelectedItemChanged;
const PickerExample({
required this.items,
required this.selectedItem,
required this.onSelectedItemChanged,
});
#override
_PickerExampleState createState() => _PickerExampleState();
}
class _PickerExampleState extends State<PickerExample> {
late final FixedExtentScrollController _controller;
#override
void initState() {
super.initState();
_controller = FixedExtentScrollController(initialItem: widget.selectedItem);
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return SizedBox(
height: 300,
child: CupertinoPicker(
scrollController: _controller,
backgroundColor: Colors.white,
itemExtent: 30.0,
children: [
for (final item in widget.items) Center(child: Text(item)),
],
onSelectedItemChanged: widget.onSelectedItemChanged,
),
);
}
}
You could also find an interactive example in this DartPad.

Related

pass value between bottomNavigationBar views

How am I supposed to pass a value in this big mess called Flutter?
30 years old php global $var wasn't good?
All these years were to come up with setState, passed in a controller which get redeclared as a key inside a stateful widget that receive the value from a Navigator?
By the way, I tried using Navigator.push but it seems to open a completely new window, the value is there but I'd need it to show in the tab body not in a new window, below is my code:
main.dart
import 'dart:core';
import 'dart:developer';
import 'dart:io';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter App',
theme: ThemeData(
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: HomeView(),
);
}
}
class HomeView extends StatefulWidget {
#override
_HomeViewState createState() => _HomeViewState();
}
class _HomeViewState extends State<HomeView> {
final tabs = [QRViewExample(), SecondView(res: '')];
int _currentIndex = 0;
#override
void initState() {
setState(() {});
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
toolbarHeight: 40.0,
elevation: 0,
centerTitle: true,
title: Text('Flutter App'),
),
body: tabs[_currentIndex],
bottomNavigationBar: BottomNavigationBar(
backgroundColor: Colors.red,
currentIndex: _currentIndex,
type: BottomNavigationBarType.fixed,
selectedItemColor: Colors.white,
unselectedItemColor: Colors.white.withOpacity(0.5),
items: [
BottomNavigationBarItem(
icon: Icon(Icons.qr_code),
label: 'Scan',
),
BottomNavigationBarItem(
icon: Icon(Icons.list),
label: 'List',
),
],
onTap: (index) {
setState(() {
_currentIndex = index;
});
},
),
);
}
}
// SECOND TAB WIDGET (custom)
class SecondView extends StatelessWidget {
const SecondView({Key? key, required this.res}) : super(key: key);
final String? res;
#override
Widget build(BuildContext context) {
return Container(
child: Center(
child: Text(res!),
),
);
}
}
// FIRST TAB WIDGET (qrcode)
class QRViewExample extends StatefulWidget {
const QRViewExample({Key? key}) : super(key: key);
#override
State<StatefulWidget> createState() => _QRViewExampleState();
}
class _QRViewExampleState extends State<QRViewExample> {
Barcode? result;
QRViewController? controller;
final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');
#override
void reassemble() {
super.reassemble();
if (Platform.isAndroid) {
controller!.pauseCamera();
}
controller!.resumeCamera();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: Container(
height: 500,
child: Padding(
padding: EdgeInsets.all(8.0),
child: Column(
children: <Widget>[
Expanded(flex: 4, child: _buildQrView(context)),
Expanded(
flex: 1,
child: FittedBox(
fit: BoxFit.contain,
child: Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
if (result != null)
Text(
'Barcode Type: ${describeEnum(result!.format)} Data: ${result!.code}')
else
const Text('Scan a code'),
Row(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Container(
margin: const EdgeInsets.all(8),
child: ElevatedButton(
onPressed: () async {
await controller?.toggleFlash();
setState(() {});
},
child: FutureBuilder(
future: controller?.getFlashStatus(),
builder: (context, snapshot) {
return Text('Flash: ${snapshot.data}');
},
)),
),
Container(
margin: const EdgeInsets.all(8),
child: ElevatedButton(
onPressed: () async {
await controller?.flipCamera();
setState(() {});
},
child: FutureBuilder(
future: controller?.getCameraInfo(),
builder: (context, snapshot) {
if (snapshot.data != null) {
return Text(
'Camera facing ${describeEnum(snapshot.data!)}');
} else {
return const Text('loading');
}
},
)),
)
],
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Container(
margin: const EdgeInsets.all(8),
child: ElevatedButton(
onPressed: () async {
await controller?.pauseCamera();
},
child: const Text('pause',
style: TextStyle(fontSize: 20)),
),
),
Container(
margin: const EdgeInsets.all(8),
child: ElevatedButton(
onPressed: () async {
await controller?.resumeCamera();
},
child: const Text('resume',
style: TextStyle(fontSize: 20)),
),
)
],
),
],
),
),
)
],
),
),
),
);
}
Widget _buildQrView(BuildContext context) {
var scanArea = (MediaQuery.of(context).size.width < 400 ||
MediaQuery.of(context).size.height < 400)
? 150.0
: 300.0;
return QRView(
key: qrKey,
onQRViewCreated: _onQRViewCreated,
overlay: QrScannerOverlayShape(
borderColor: Colors.cyanAccent,
borderRadius: 10,
borderLength: 30,
borderWidth: 10,
cutOutSize: scanArea),
onPermissionSet: (ctrl, p) => _onPermissionSet(context, ctrl, p),
);
}
void _onQRViewCreated(QRViewController controller) {
setState(() {
this.controller = controller;
});
controller.scannedDataStream.listen((scanData) {
controller.pauseCamera();
setState(() {
result = scanData;
});
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => SecondView(res: result!.code)))
.then((value) => controller.resumeCamera());
});
}
void _onPermissionSet(BuildContext context, QRViewController ctrl, bool p) {
log('${DateTime.now().toIso8601String()}_onPermissionSet $p');
if (!p) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text('no Permission')),
);
}
}
#override
void dispose() {
controller?.dispose();
super.dispose();
}
}
How am I supposed to pass a value in this big mess called Flutter?
With state management tools like InheritedWidget, InheritedModel, Provider, BloC and many more.
30 years old php global $var wasn't good? All these years were to come up with setState, passed in a controller which get redeclared as a key inside a stateful widget that receive the value from a Navigator?
Well, you shouldn't do that and it's not meant to be done like that. We can use several methods to propagate data down the widget tree. Let me explain this with InheritedWidget. But sometimes you want to go for Provider which is a wrapper class for InheritedWidget.
First we create a class named QRListModel which extends InheritedModel:
class QRListModel extends InheritedWidget {
final List<Barcode> qrList = []; // <- This holds our data
QRListModel({required super.child});
#override
bool updateShouldNotify(QRListModel oldWidget) {
return !listEquals(oldWidget.qrList, qrList);
}
static QRListModel of(BuildContext context) {
final QRListModel? result = context.dependOnInheritedWidgetOfExactType<QRListModel>();
assert(result != null, 'No QRListModel found in context');
return result!;
}
}
updateShouldNotify is a method we have to override to tell Flutter, when we want the widgets to rebuild. We want this to happen when the list changes. The of method is just a handy way to access the QRListModel.
Now wrap a parent widget of both the scan tab view and the list tab view inside QRListModel. We go for HomeView:
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter App',
theme: ThemeData(
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: QRListModel(child: HomeView()), // <- here!
);
}
}
We can take any parent widget but it should be a class where we don't call setState. Otherwise our QRListModel also gets rebuilt and our list is gone.
Now we can access QRListModel from anywhere inside the subtree. We need it here:
void _onQRViewCreated(QRViewController controller) {
setState(() {
this.controller = controller;
this.controller!.resumeCamera();
});
controller.scannedDataStream.listen((scanData) async {
controller.pauseCamera();
QRListModel.of(context).qrList.add(scanData); // <- Here we access the list
await showDialog(
context: context,
builder: (context) => SimpleDialog(
title: Text("Barcode was added!"),
children: [
Text(scanData.code!)
],
)
);
});
}
And here we read the list:
class SecondView extends StatelessWidget {
const SecondView({Key? key, required this.res}) : super(key: key);
final String? res;
#override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: QRListModel.of(context).qrList.length,
itemBuilder: (context, index) {
return Card(
child: ListTile(
title: Text(QRListModel.of(context).qrList[index].code ?? "NO"),
),
);
}
);
}
}
Now both pages have access to the qr list. Please do mind that a InheritedWidget can only have final fields. So if you need mutable fields, you need an additional wrapper class. We don't need it as we don't change the list but only its elements.
By the way: You shouldn't call setState inside initState. You did this here:
class _HomeViewState extends State<HomeView> {
final tabs = [QRViewExample(), SecondView(res: '')];
int _currentIndex = 0;
#override
void initState() {
setState(() {}); // <- Don't call setState inside initState!
super.initState();
}

Changing the state Widget of one through another Widget

MyHomePageState:
Widget build(BuildContext context) {
double screenWidth = MediaQuery.of(context).size.width;
return Scaffold(
backgroundColor: bgColor,
body: ListView(
children: <Widget>[
Stack(
alignment: Alignment.topCenter,
children: <Widget>[
mainWidget(),
],
),
connectedStatusText(),
],
));
}
I'm trying to change the status of connectedStatusText() from mainWidget()!
My connectedStatus:
class connectedStatusText extends StatefulWidget
{
State<connectedStatusText> createState() {
return connectedStatus();
}
}
class connectedStatus extends State<connectedStatusText> {
String status = "IDLE";
#override
Widget build(BuildContext context) {
return Align(
alignment: Alignment.center,
child: RichText(
textAlign: TextAlign.center,
text: TextSpan(text: 'Status:', style: connectedStyle, children: [
TextSpan(text: status, style: disconnectedRed)
]),
),
);
}
}
I want to change the $status text to "connected" through ontap of mainWidget().
mainWidget:
....
class mainWidget extends StatefulWidget
{
MyED createState() => new MyED();
}
class MyED extends State<mainWidget> {
child: new GestureDetector(
onTap: () => setState(() {
//change here
}
tried to set a global variable to connectedStatus:
GlobalKey<connectedStatus> key = GlobalKey<connectedStatus>();
and change by ontap...
child: new GestureDetector(
onTap: () => setState(() {
//change here
key.currentState.status = "CONNECTED";
}
)
}
but it does not work!
Any help for me to change this text through another place?
Please refer to below example code to update state using ValueNotifier and ValueListenableBuilder.
ValueNotifer & ValueListenableBuilder can be used to hold value and update widget by notifying its listeners and reducing number of times widget tree getting rebuilt.
import 'package:flutter/material.dart';
const Color darkBlue = Color.fromARGB(255, 18, 32, 47);
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(
scaffoldBackgroundColor: darkBlue,
),
debugShowCheckedModeBanner: false,
home: Screen2(),
);
}
}
class Screen2 extends StatefulWidget {
final String userId; // receives the value
const Screen2({Key key, this.userId}) : super(key: key);
#override
_Screen2State createState() => _Screen2State();
}
class _Screen2State extends State<Screen2> {
final ValueNotifier<bool> updateStatus = ValueNotifier(false);
#override
Widget build(BuildContext context) {
double screenWidth = MediaQuery.of(context).size.width;
return Scaffold(
backgroundColor: Colors.blue,
body: ListView(
children: <Widget>[
Stack(
alignment: Alignment.topCenter,
children: <Widget>[
mainWidget(
updateStatus: updateStatus,
),
],
),
connectedStatusText(
updateStatus: updateStatus,
),
],
),
); // uses the value
}
}
class connectedStatusText extends StatefulWidget {
final ValueNotifier<bool> updateStatus;
connectedStatusText({
Key key,
this.updateStatus,
}) : super(key: key);
State<connectedStatusText> createState() {
return connectedStatus();
}
}
class connectedStatus extends State<connectedStatusText> {
String status = "IDLE";
#override
Widget build(BuildContext context) {
return Align(
alignment: Alignment.center,
child: /*
In order update widget we can use ValueListenableBuilder which updates the particular widget when the value changes (ValueNotifier value)
*/
ValueListenableBuilder(
valueListenable: widget.updateStatus,
builder: (context, snapshot, child) {
return RichText(
textAlign: TextAlign.center,
text: TextSpan(text: 'Status:', children: [
TextSpan(
text: (widget.updateStatus.value == true)
? "Active"
: status,
)
]),
);
}),
);
}
}
class mainWidget extends StatefulWidget {
final String userId; // receives the value
final ValueNotifier<bool> updateStatus;
mainWidget({
Key key,
this.userId,
this.updateStatus,
}) : super(key: key);
#override
_mainWidgetState createState() => _mainWidgetState();
}
class _mainWidgetState extends State<mainWidget> {
#override
Widget build(BuildContext context) {
return GestureDetector(
onTap: () {
widget.updateStatus.value = !widget.updateStatus.value;
},
child: ValueListenableBuilder(
valueListenable: widget.updateStatus,
builder: (context, snapshot, child) {
return Text(snapshot.toString());
}));
// uses the value
}
}

How to SetState() of Parent when child is Updated in flutter

I have a list view and inside the list view, there is a child widget which can grow when user tap on that.
I want to scroll to the bottom of the list when the user taps on the child and it grows.
when I pass callback function from the parent to the child to scroll to the bottom.
and call the function when the user tap on the child.
I get the following error: setState() or markNeedsBuild() called during build.
class MyWidget extends StatefulWidget {
#override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
ScrollController _controller = ScrollController();
void scrollToLast() {
print("trying to scroll");
setState(() {
_controller.animateTo(
_controller.position.maxScrollExtent,
duration: Duration(microseconds: 300),
curve: Curves.easeInOut,
);
});
}
#override
Widget build(BuildContext context) {
return ListView(
controller: _controller,
children: <Widget>[
MyChildWidget(
scrollToLast: this.scrollToLast,
)
],
);
}
}
class MyChildWidget extends StatefulWidget {
final VoidCallback scrollToLast;
MyChildWidget({
this.scrollToLast,
});
#override
_MyChildWidgetState createState() => _MyChildWidgetState(
scrollToLast: this.scrollToLast,
);
}
class _MyChildWidgetState extends State<MyChildWidget> {
final VoidCallback scrollToLast;
_MyChildWidgetState({
this.scrollToLast,
});
int count = 5;
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {
setState(() {
this.count += 5;
});
this.scrollToLast();
},
child: Column(
mainAxisSize: MainAxisSize.max,
children: List<Widget>.generate(
this.count,
(int index) => Container(
color: Colors.blue,
height: 30,
margin: EdgeInsets.all(10),
),
),
),
);
}
}
You can copy paste run full code below
You can use WidgetsBinding.instance.addPostFrameCallback
code snippet
void scrollToLast() {
print("trying to scroll");
WidgetsBinding.instance.addPostFrameCallback((_) {
setState(() {
_controller.animateTo(
_controller.position.maxScrollExtent,
duration: Duration(microseconds: 300),
curve: Curves.easeInOut,
);
});
});
}
working demo
full code
import 'package:flutter/material.dart';
class MyWidget extends StatefulWidget {
#override
_MyWidgetState createState() => _MyWidgetState();
}
class _MyWidgetState extends State<MyWidget> {
ScrollController _controller = ScrollController();
void scrollToLast() {
print("trying to scroll");
WidgetsBinding.instance.addPostFrameCallback((_) {
setState(() {
_controller.animateTo(
_controller.position.maxScrollExtent,
duration: Duration(microseconds: 300),
curve: Curves.easeInOut,
);
});
});
}
#override
Widget build(BuildContext context) {
return ListView(
controller: _controller,
children: <Widget>[
MyChildWidget(
scrollToLast: this.scrollToLast,
)
],
);
}
}
class MyChildWidget extends StatefulWidget {
final VoidCallback scrollToLast;
MyChildWidget({
this.scrollToLast,
});
#override
_MyChildWidgetState createState() => _MyChildWidgetState(
/*scrollToLast: this.scrollToLast,*/
);
}
class _MyChildWidgetState extends State<MyChildWidget> {
/* final VoidCallback scrollToLast;
_MyChildWidgetState({
this.scrollToLast,
});*/
int count = 5;
#override
Widget build(BuildContext context) {
return InkWell(
onTap: () {
setState(() {
this.count += 5;
});
widget.scrollToLast();
},
child: Column(
mainAxisSize: MainAxisSize.max,
children: List<Widget>.generate(
this.count,
(int index) => Container(
color: Colors.blue,
height: 30,
margin: EdgeInsets.all(10),
child: Text('$index'),
),
),
),
);
}
}
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(
title: "Demo",
),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(child: MyWidget()),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}

Child widget send dynamic data

I have a two-page app. On-Page One I am showing an UUID which changes every 1 second. It is shown using listview. Once the user clicks on the list view it goes to the second page and shows the data on that card.
It should have been the changing UUID. but the data shown is static UUID. How I can pass the data changed on page 1 to page 2?
import 'dart:async';
import 'package:uuid/uuid.dart';
import 'package:uuid/uuid_util.dart';
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
List<EuropeanCountries> europeanCountries = [];
class EuropeanCountries {
String myText;
String myUuid;
EuropeanCountries({
this.myText,
this.myUuid,
});
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
int _perPage = 50;
ScrollController _myScrollController = ScrollController();
void _incrementCounter() async {
const ThreeSec = const Duration(seconds: 1);
this._counter++;
europeanCountries.insert(
0,
EuropeanCountries(
myText: this._counter.toString(),
));
print(europeanCountries[0].myText);
setState(() {});
}
void getMoreData() {
print('adding More Product ');
europeanCountries.add(EuropeanCountries(
myText: this._counter.toString(),
));
//europeanCountries.insert(0, EuropeanCountries(myText:this._counter.toString(), myButtonText: "", myColor: Colors.blue));
setState(() {});
}
void generateUUID() async {
var uuid = Uuid();
for (int i = 0; i < 6000; i++) {
await new Future.delayed(new Duration(milliseconds: 1000));
for (EuropeanCountries currCountry in europeanCountries) {
currCountry.myUuid = uuid.v1();
}
setState(() {});
}
}
#override
void initState() {
// TODO: implement initState
super.initState();
generateUUID();
_myScrollController.addListener(() {
double maxscroll = _myScrollController.position.maxScrollExtent;
double currentScroll = _myScrollController.position.pixels;
double delta = MediaQuery.of(context).size.height * 0.25;
print("mac Scroll Controller - " + maxscroll.toString());
print("Current Scroll Controller - " + currentScroll.toString());
print("delta Scroll Controller - " + delta.toString());
if ((maxscroll - currentScroll) < delta) {
getMoreData();
}
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: _myListView(context),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
Widget _myListView(BuildContext context) {
// backing data
return Container(
child: europeanCountries.length == 0
? Center(
child: Text('No Product to Display'),
)
: ListView.builder(
controller: _myScrollController,
itemCount: europeanCountries.length,
reverse: false,
itemBuilder: (context, index) {
return myContainer(index: index);
},
),
);
}
}
class myContainer extends StatefulWidget {
final int index;
const myContainer({Key key, this.index}) : super(key: key);
#override
_myContainerState createState() => _myContainerState();
}
class _myContainerState extends State<myContainer> {
#override
Widget build(BuildContext context) {
return Container(
height: 120,
decoration: BoxDecoration(
border: Border.all(color: Colors.blue[700]),
shape: BoxShape.rectangle,
borderRadius: BorderRadius.all(Radius.circular(8)),
),
margin: EdgeInsets.all(20),
child: Column(
children: <Widget>[
Text(europeanCountries[widget.index].myText),
SizedBox(
height: 15,
),
RaisedButton(
child: Text('Detail'),
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => SecondRoute(
myCountry: europeanCountries[widget.index],
)),
);
},
color: Colors.blue[700],
textColor: Colors.white,
padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
splashColor: Colors.black,
),
Text(europeanCountries[widget.index].myUuid != null
? europeanCountries[widget.index].myUuid
: 'Default')
],
),
);
}
}
class SecondRoute extends StatefulWidget {
final EuropeanCountries myCountry;
const SecondRoute({Key key, this.myCountry}) : super(key: key);
#override
_SecondRouteState createState() => _SecondRouteState();
}
class _SecondRouteState extends State<SecondRoute> {
#override
void didUpdateWidget(SecondRoute oldWidget) {
// TODO: implement didUpdateWidget
super.didUpdateWidget(oldWidget);
setState(() {});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Second Route"),
),
body: Center(
child: RaisedButton(
onPressed: () {
Navigator.pop(context);
},
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Center(
child: Text(widget.myCountry.myUuid != null
? widget.myCountry.myText
: 'default'),
),
SizedBox(height: 15),
Center(
child: Text(widget.myCountry.myUuid != null
? widget.myCountry.myUuid
: 'default'),
),
],
),
),
),
);
}
}
https://imgur.com/VqRfcZY
<blockquote class="imgur-embed-pub" lang="en" data-id="VqRfcZY"></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

Flutter: Dissmissible widgets disable Tabview drag detection

I have two tabs, the left tab having a list of tiles and the right tab having nothing. The user can drag the screen from right-to-left or left-to-right to get from one tab to the other.
The left tab has a list of dismissible tiles that only have "direction: DismissDirection.startToEnd" (from left-to-right) enabled so that the user can still theoretically drag (from right-to-left) to go to the right tab.
However, I believe the Dismissible widget still receives the right-to-left drag information which is disabling the TabView drag to change tabs.
In essence, how do I allow the right-to-left drag to be detected by only the TabView and not the Dismissible item?
If an explicit solution/example with code snippets can be given, I would very very much appreciate the help!
Here's a paste for your main.dart file:
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter/semantics.dart';
void main() {
SystemChrome.setPreferredOrientations([
DeviceOrientation.portraitUp,
DeviceOrientation.portraitDown,
]);
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark(),
home: MainPage(),
);
}
}
class MainPage extends StatefulWidget {
#override
State<StatefulWidget> createState() => _MainPageState();
}
class _MainPageState extends State<MainPage>
with SingleTickerProviderStateMixin {
TabController _tabController;
#override
void initState() {
_tabController = TabController(vsync: this, length: 2, initialIndex: 1);
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Container(
color: Colors.black,
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Expanded(
child: TabBarView(
controller: _tabController,
children: <Widget>[
TabWithSomething(),
TabWithNothing(),
],
),
),
],
),
),
),
);
}
}
class TabWithNothing extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: Container(
child: Text("Swipe from left-to-right!"),
),
);
}
}
class TabWithSomethingItem implements Comparable<TabWithSomethingItem> {
TabWithSomethingItem({this.index, this.name, this.subject, this.body});
TabWithSomethingItem.from(TabWithSomethingItem item)
: index = item.index,
name = item.name,
subject = item.subject,
body = item.body;
final int index;
final String name;
final String subject;
final String body;
#override
int compareTo(TabWithSomethingItem other) => index.compareTo(other.index);
}
class TabWithSomething extends StatefulWidget {
const TabWithSomething({Key key}) : super(key: key);
static const String routeName = '/material/leave-behind';
#override
TabWithSomethingState createState() => TabWithSomethingState();
}
class TabWithSomethingState extends State<TabWithSomething> {
List<TabWithSomethingItem> TabWithSomethingItems;
void initListItems() {
TabWithSomethingItems =
List<TabWithSomethingItem>.generate(10, (int index) {
return TabWithSomethingItem(
index: index,
name: 'Item $index',
subject: 'Swipe from left-to-right to delete',
body: "Swipe from right-to-left to go back to old tab");
});
}
#override
void initState() {
super.initState();
initListItems();
}
void _handleDelete(TabWithSomethingItem item) {
setState(() {
TabWithSomethingItems.remove(item);
});
}
#override
Widget build(BuildContext context) {
Widget body;
body = ListView(
children:
TabWithSomethingItems.map<Widget>((TabWithSomethingItem item) {
return _TabWithSomethingListItem(
item: item,
onDelete: _handleDelete,
dismissDirection: DismissDirection.startToEnd,
);
}).toList());
return body;
}
}
class _TabWithSomethingListItem extends StatelessWidget {
const _TabWithSomethingListItem({
Key key,
#required this.item,
#required this.onDelete,
#required this.dismissDirection,
}) : super(key: key);
final TabWithSomethingItem item;
final DismissDirection dismissDirection;
final void Function(TabWithSomethingItem) onDelete;
void _handleDelete() {
onDelete(item);
}
#override
Widget build(BuildContext context) {
final ThemeData theme = Theme.of(context);
return Semantics(
customSemanticsActions: <CustomSemanticsAction, VoidCallback>{
const CustomSemanticsAction(label: 'Delete'): _handleDelete,
},
child: Dismissible(
key: ObjectKey(item),
direction: dismissDirection,
onDismissed: (DismissDirection direction) => _handleDelete(),
background: Container(
color: theme.primaryColor,
child: const ListTile(
leading: Icon(Icons.delete, color: Colors.white, size: 36.0))),
child: Container(
decoration: BoxDecoration(
color: theme.canvasColor,
border: Border(bottom: BorderSide(color: theme.dividerColor))),
child: ListTile(
title: Text(item.name),
subtitle: Text('${item.subject}\n${item.body}'),
isThreeLine: true),
),
),
);
}
}
UPDATE:
I'm thinking we could change the "dismissible.dart" file to change the "TabControlller", but i'm not sure how I might do that.
In the "dismissible.dart" file:
...
void _handleDragUpdate(DragUpdateDetails details) {
if (!_isActive || _moveController.isAnimating)
return;
final double delta = details.primaryDelta;
if (delta < 0) print(delta); // thinking of doing something here
...