Question about Flutter State and retrieving variables from State vs StatefulWidget - flutter

Here's the context:
In my app, users can create a question, and all questions will be displayed on a certain page. This is done with a ListView.builder whose itemBuilder property returns a QuestionTile.
The problem:
If I create a new question, the text of the new question is (usually) displayed as the text of the previous question.
Here's a picture of me adding three questions in order, "testqn123", "testqn456", "testqn789", but all are displayed as "testqn123".
Hot restarting the app will display the correct texts for each question, but hot reloading wont work.
In my _QuestionTileState class, if I change the line responsible for displaying the text of the question on the page, from
child: Text(text)
to
child: Text(widget.text)
the issue will be resolved for good. I'm not super familiar with how hot restart/reload and state works in flutter, but can someone explain all of this?
Here is the code for QuestionTile and its corresponding State class, and the line changed is the very last line with words in it:
class QuestionTile extends StatefulWidget {
final String text;
final String roomName;
final String roomID;
final String questionID; //
QuestionTile({this.questionID, this.text, this.roomName, this.roomID});
#override
_QuestionTileState createState() => _QuestionTileState(text);
}
class _QuestionTileState extends State<QuestionTile> {
final String text;
int netVotes = 0;
bool expand = false;
bool alreadyUpvoted = false;
bool alreadyDownvoted = false;
_QuestionTileState(this.text);
void toggleExpansion() {
setState(() => expand = !expand);
}
#override
Widget build(BuildContext context) {
RoomDbService dbService = RoomDbService(widget.roomName, widget.roomID);
final user = Provider.of<User>(context);
print(widget.text + " with questionID of " + widget.questionID);
return expand
? ExpandedQuestionTile(text, netVotes, toggleExpansion)
: Card(
elevation: 10,
child: Padding(
padding: const EdgeInsets.fromLTRB(10, 7, 15, 7),
child: GestureDetector(
onTap: () => {
Navigator.pushNamed(context, "/ChatRoomPage", arguments: {
"question": widget.text,
"questionID": widget.questionID,
"roomName": widget.roomName,
"roomID": widget.roomID,
})
},
child: new Row(
// crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Column(
// the stack overflow functionality
children: <Widget>[
InkWell(
child: alreadyUpvoted
? Icon(Icons.arrow_drop_up,
color: Colors.blue[500])
: Icon(Icons.arrow_drop_up),
onTap: () {
dynamic result = dbService.upvoteQuestion(
user.uid, widget.questionID);
setState(() {
alreadyUpvoted = !alreadyUpvoted;
if (alreadyDownvoted) {
alreadyDownvoted = false;
}
});
},
),
StreamBuilder<DocumentSnapshot>(
stream: dbService.getQuestionVotes(widget.questionID),
builder: (context, snapshot) {
if (!snapshot.hasData) {
return Center(child: CircularProgressIndicator());
} else {
// print("Current Votes: " + "${snapshot.data.data["votes"]}");
// print("questionID: " + widget.questionID);
return Text("${snapshot.data.data["votes"]}");
}
},
),
InkWell(
child: alreadyDownvoted
? Icon(Icons.arrow_drop_down,
color: Colors.red[500])
: Icon(Icons.arrow_drop_down),
onTap: () {
dbService.downvoteQuestion(
user.uid, widget.questionID);
setState(() {
alreadyDownvoted = !alreadyDownvoted;
if (alreadyUpvoted) {
alreadyUpvoted = false;
}
});
},
),
],
),
Container(
//color: Colors.red[100],
width: 290,
child: Align(
alignment: Alignment.centerLeft,
child: Text(text)), // problem solved if changed to Text(widget.text)
),
}
}

You can wrap your UI with a Stream Builder, this will allow the UI to update every time any value changes from Firestore.
Since you are using an item builder you can wrap the widget that is placed with the item builder.
That Should update the UI

Related

How to change variable value in flutter with bloc?

Want to ask is How to change variable value with stream flutter?
You think my question is so fundamental and I can search in everywhere on internet. But in this scenario with stream, I can't change the variable value with method. How I need to do? please guide me. I will show with example.
Here, this is bloc class code with rxDart.
class ChangePinBloc {
final ChangePinRepository _changePinRepository = ChangePinRepository();
final _isValidateConfirmNewPinController = PublishSubject();
String oldPin = '';
Stream get isValidateConfirmNewPinStream =>
_isValidateConfirmNewPinController.stream;
void checkValidateConfirmNewPin(
{required String newPinCode, required String oldPinCode}) {
if (newPinCode == oldPinCode) {
oldPin = oldPinCode;
changePin(newCode: newPinCode);
isValidateConfirmPin = true;
_isValidateConfirmNewPinController.sink.add(isValidateConfirmPin);
} else {
isValidateConfirmPin = false;
_isValidateConfirmNewPinController.sink.add(isValidateConfirmPin);
}
}
void changePin({required String newCode}) async {
changePinRequestBody['deviceId'] = oldPin;
}
dispose() {
}
}
Above code, want to change the value of oldPin value by calling checkValidateConfirmNewPin method from UI. And want to use that oldPin value in changePin method. but oldPin value in changePin always get empty string.
This is the calling method checkValidateConfirmNewPin from UI for better understanding.
PinCodeField(
pinLength: 6,
onComplete: (value) {
pinCodeFieldValue = value;
changePinBloc.checkValidateConfirmNewPin(
newPinCode: value,
oldPinCode: widget.currentPinCodeFieldValue!);
},
onChange: () {},
),
Why I always get empty String although assign a value to variable?
Lastly, this is complete code that calling state checkValidateConfirmNewPin from UI.
void main() {
final changePinBloc = ChangePinBloc();
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: StreamBuilder(
stream: changePinBloc.isValidateConfirmNewPinStream,
builder: (context, AsyncSnapshot pinValidateSnapshot) {
return Stack(
children: [
Positioned.fill(
child: Column(
children: [
const PinChangeSettingTitle(
title: CONFIRM_NEW_PIN_TITLE,
subTitle: CONFIRM_NEW_PIN_SUBTITLE,
),
const SizedBox(
height: margin50,
),
Padding(
padding: const EdgeInsets.only(
left: margin50, right: margin50),
child: PinCodeField(
pinLength: 6,
onComplete: (value) {
changePinBloc.checkValidateConfirmNewPin(
newPinCode: value,
oldPinCode: widget.newCodePinValue!,
);
},
onChange: () {},
),
)
],
),
),
pinValidateSnapshot.hasData
? pinValidateDataState(pinValidateSnapshot, changePinBloc)
: const Positioned.fill(
child: SizedBox(),
),
],
);
},
),
),
);
}
}
To update the variable you should emit a new state using emit() method.
Just make sure your bloc is correct as it should inherit from Bloc object. Read flutter_bloc documentation to know how to use it.
A simple example:
class ExampleBloc extends Bloc<ExampleEvent, ExampleState> {
ExampleBloc() : super(ExampleInitial()) {
on<ExampleEvent>((event, emit) {
//Do some logic here
emit(ExampleLoaded());
});
}
}

What can I do to make my ListView stop incrementing the data every time I open it?

My first Flutter project, which is a tricycle booking system, has just begun. Using the ListView widget, I wanted to display all of the active passengers that are saved in my Firebase Database. However, when I attempted to display it and place it in a List, all functions are working fine at first click. When you click the button to view the ListView a second time, all of the saved data are replicated. The list continues after my third click and grows by three. The image below illustrates what takes place when I repeatedly click on the ListView.
These are the blocks of code that are utilized for this functionality:
CODE for Functionality
retrieveOnlinePassengersInformation(List onlineNearestPassengersList) async
{
dList.clear();
DatabaseReference ref = FirebaseDatabase.instance.ref().child("passengers");
for(int i = 0; i<onlineNearestPassengersList.length; i++)
{
await ref.child(onlineNearestPassengersList[i].passengerId.toString())
.once()
.then((dataSnapshot)
{
var passengerKeyInfo = dataSnapshot.snapshot.value;
dList.add(passengerKeyInfo);
print("passengerKey Info: " + dList.toString());
});
}
}
CODE for the UI
body: ListView.builder(
itemCount: dList.length,
itemBuilder: (BuildContext context, int index)
{
return GestureDetector(
onTap: ()
{
setState(() {
chosenPassengerId = dList[index]["id"].toString();
});
Navigator.pop(context, "passengerChoosed");
},
child: Card(
color: Colors.grey,
elevation: 3,
shadowColor: Colors.green,
margin: EdgeInsets.all(8.0),
child: ListTile(
leading: Padding(
padding: const EdgeInsets.only(top: 2.0),
child: Icon(
Icons.account_circle_outlined,
size: 26.sp,
color: Color(0xFF777777),
),
),
title: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
Row(
children: [
Text(
dList[index]["first_name"] + " " + dList[index]["last_name"],
style: TextStyle(
fontFamily: "Montserrat",
fontSize: 18.sp,
fontWeight: FontWeight.bold,
color: Colors.black,
),
),
Icon(
Icons.verified_rounded,
color: Color(0xFF0CBC8B),
size: 22.sp,
),
],
),
],
),
),
),
);
},
),
Expected Result:
Actual Result AFTER CLICKING MANY TIMES:
Made a demo for you how to call function once on load
class CustomWidgetName extends StatefulWidget {
const CustomWidgetName({Key? key}) : super(key: key);
#override
State<CustomWidgetName> createState() => _CustomWidgetNameState();
}
class _CustomWidgetNameState extends State<CustomWidgetName> {
List? dList = [];
void myDataFunction() async {
// do your data fetch and add to dList
final newList = [];
setState(() {
dList = newList;
});
}
#override
void initState() {
super.initState();
myDataFunction(); // Call your async function here
}
#override
Widget build(BuildContext context) {
return Scaffold();
}
}
Try this solution.
Update SelectNearestActiveDriversScreen() like this:
class SelectNearestActiveDriversScreen extends StatefulWidget
{
DatabaseReference? referenceRideRequest;
final List list;
SelectNearestActiveDriversScreen({this.referenceRideRequest, required this.list});
#override
State<SelectNearestActiveDriversScreen> createState() => _SelectNearestActiveDriversScreenState();
}
In homepage.dart, declare List dList = [];, then change line 378 like this:
Navigator.push(context, MaterialPageRoute(builder: (c)=> SelectNearestActiveDriversScreen(list: dList)));
In SelectNearestActiveDriversScreen(), replace all dList with widget.list.
Finally, if you are using variables in a specific file declare them in that file(not in another file) or pass them in the constructor of the class / file / widget /screen you are calling.
If you would rather use global variables and state managers go for packages like GetX.

Flutter provider consumer removes my items

I'm trying to build a sort function in order to sort JSON data.
For this, I have a button that opens a "showModalBottomSheet".
Within it I can choose the following data of the school class numbers.
So in my data I have 6 classrooms when loading in my constructor.
My filter is represented by buttons which are active or not if the filter contains the number of the classroom. My code works pretty much, my problem is that when I select a filter button in order to activate or not the filter, the button is deleted instead of staying but changing color
My notifier :
class TablesNotifier with ChangeNotifier {
// Services
// ---------------------------------------------------------------------------
final jsonSelectorService = locator<JsonSelectorService>();
// Variables
// ---------------------------------------------------------------------------
//all data from my classerooms in JSON
List<ClassroomModel> classrooms;
// Data that I will display and reconstruct based on my filter parameters
List<ClassroomModel> classroomsFiltered;
List<int> numberOfClassrooms = List();
// Model which will store the parameters of my filters and as a function I will load the data to display
FilterClassroomsModel filterClassroomsModel = FilterClassroomsModel();
// Constructor
// ---------------------------------------------------------------------------
TablesNotifier(){
_initialise();
}
// Initialisation
// ---------------------------------------------------------------------------
Future _initialise() async{
classrooms = await jsonSelectorService.classrooms('data');
classroomsFiltered = classrooms ;
// I install the number of existing classrooms
// Here the result is [1,2,3,4,5,6]
classrooms.forEach((element) {
if(!numberOfClassrooms.contains(element.type)){
numberOfClassrooms.add(element.type);
}
});
// I install the number of classrooms activated by default in my filter
// As I decide to display all my classrooms by default
// My filter on the classrooms must contain all the loaded classrooms
filterClassroomsModel.classrooms = numberOfClassrooms;
notifyListeners();
}
// Functions public
// ---------------------------------------------------------------------------
void saveClassroomsSelected(int index)
{
// Here my classroom model also contains the numbers of the classrooms that I want to filter
if(filterClassroomsModel.classrooms.contains(index)){
filterClassroomsModel.classrooms.remove(index);
}else{
filterClassroomsModel.classrooms.add(index);
}
notifyListeners();
}
}
I have identified that in my function initialize () if I change my code by this it works :
filterClassroomsModel.classrooms= numberOfClassrooms; // this
filterClassroomsModel.classrooms= [1,2,3,4,5,6]; // By this
I am losing the dynamic side of my classroom calculation and that does not suit me. But I don't understand this behavior.
My view :
class TableScreen extends StatelessWidget {
final String title;
TableScreen({Key key, #required this.title}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
drawer: MenuDrawerComponent.builder(context),
appBar: AppBar(
backgroundColor: AppColors.backgroundDark,
elevation: 0,
centerTitle: true,
title: Text(title),
),
floatingActionButton: FloatingActionButton.extended(
icon: Icon(Icons.sort),
label: Text('Filter'),
onPressed: () async{
slideSheet(context);
},
backgroundColor: AppColors.contrastPrimary,
),
body: _buildBody(context),
);
}
Widget _buildBody(BuildContext context)
{
var _tableProvider = Provider.of<TablesNotifier>(context);
if(_tableProvider.chargesFiltered == null){
return Center(
child: CircularProgressIndicator(
backgroundColor: AppColors.colorShadowLight,
),
);
}else{
return Column(
children: <Widget>[
Expanded(
child: Container(
padding: EdgeInsets.only(top: 10, right : 20, left : 20),
child: ListView.builder(
itemCount: _tableProvider.classroomsFiltered.length,
itemBuilder: (context, index){
return Container(
child: Column(
children: [
Row(
// Some classrooms data
),
],
),
);
},
),
)
),
],
);
}
}
void slideSheet(BuildContext context) {
var _tableProvider = Provider.of<TablesNotifier>(context, listen:false);
showModalBottomSheet(
context: context,
isScrollControlled: true,
isDismissible: true,
builder: (context) {
return Wrap(
children: [
Container(
color: Color(0xFF737373),
child: Container(
child: Column(
children: <Widget>[
// Some filters ...
// Here I want to rebuild the list of button for show the changes
ChangeNotifierProvider.value(
value: _tableProvider,
child: Consumer<TablesNotifier>(
builder: (context, model, child){
return _listOfClassrooms(context);
}
),
),
],
),
),
),
]
);
});
}
Widget _listOfClassrooms(BuildContext context){
var _tableProvider = Provider.of<TablesNotifier>(context);
List<Widget> list = List<Widget>();
var listClassrooms = _tableProvider.numberOfClassrooms;
var filterClassrooms = _tableProvider.filterClassroomsModel.classrooms;
for (var i = 0; i < listClassrooms.length; i++) {
int selectIndex = 0;
if(filterClassrooms.contains(listClassrooms[i])){
selectIndex = listClassrooms[i];
}
list.add(
RadioComponent(
text: "${listClassrooms[i]}",
index: listClassrooms[i],
width: (MediaQuery.of(context).size.width - 56) /3,
selectedIndex: selectIndex,
onPressed: _tableProvider.saveChargesSelected,
),
);
}
return Wrap(
spacing: 8.0, // gap between adjacent chips
runSpacing: 8.0, // gap between lines
children: list
);
}
}
My FilterClassroomsModel :
class FilterClassroomsModel {
int order;
int sort;
List<int> classrooms;
FilterClassroomsModel ({
this.order = 0,
this.sort = 0,
this.classrooms = const[],
});
#override
String toString() {
return '{ '
'${this.order}, '
'${this.sort}, '
'${this.classrooms}, '
'}';
}
}
EDIT : Resolved topic. Thanks to Javachipper.
In the notifier I replace that :
filterClassroomsModel.classrooms = numberOfClassrooms;
By that :
filter.classrooms = List<int>();
filter.classrooms.addAll(numberOfClassrooms);
change this:
filterClassroomsModel.classrooms = numberOfClassrooms;
to:
filterClassroomsModel.classrooms.addAll(numberOfClassrooms);
Update (you can also do it like this):
filterClassroomsModel.classrooms= new List<int>();
filterClassroomsModel.classrooms.addAll(numberOfClassrooms);

Can I use Dismissible without actually dismissing the widget?

I'm trying to make a widget that can be swiped to change the currently playing song in a playlist. I'm trying to mimic how other apps do it by letting the user swipe away the current track and the next one coming in. Dismissible is so close to what I actually want. It has a nice animation and I can easily use the onDismissed function to handle the logic. My issue is that Dismissible actually wants to remove the widget from the tree, which I don't want.
The widget I'm swiping gets updated with a StreamBuilder when the song changes, so being able to swipe away the widget to a new one would be perfect. Can I do this or is there a better widget for my needs?
Here's the widget I'm working on:
class NowPlayingBar extends StatelessWidget {
const NowPlayingBar({
Key key,
}) : super(key: key);
#override
Widget build(BuildContext context) {
return StreamBuilder<ScreenState>(
stream: _screenStateStream,
builder: (context, snapshot) {
if (snapshot.hasData) {
final screenState = snapshot.data;
final queue = screenState.queue;
final mediaItem = screenState.mediaItem;
final state = screenState.playbackState;
final processingState =
state?.processingState ?? AudioProcessingState.none;
final playing = state?.playing ?? false;
if (mediaItem != null) {
return Container(
width: MediaQuery.of(context).size.width,
child: Dismissible(
key: Key("NowPlayingBar"),
onDismissed: (direction) {
switch (direction) {
case DismissDirection.startToEnd:
AudioService.skipToNext();
break;
case DismissDirection.endToStart:
AudioService.skipToPrevious();
break;
default:
throw ("Unsupported swipe direction ${direction.toString()} on NowPlayingBar!");
}
},
child: ListTile(
leading: AlbumImage(itemId: mediaItem.id),
title: mediaItem == null ? null : Text(mediaItem.title),
subtitle: mediaItem == null ? null : Text(mediaItem.album),
trailing: Row(
mainAxisSize: MainAxisSize.min,
children: [
if (playing)
IconButton(
onPressed: () => AudioService.pause(),
icon: Icon(Icons.pause))
else
IconButton(
onPressed: () => AudioService.play(),
icon: Icon(Icons.play_arrow)),
],
),
),
),
);
} else {
return Container(
width: MediaQuery.of(context).size.width,
child: ListTile(
title: Text("Nothing playing..."),
));
}
} else {
return Container(
width: MediaQuery.of(context).size.width,
// The child below looks pretty stupid but it's actually genius.
// I wanted the NowPlayingBar to stay the same length when it doesn't have data
// but I didn't want to actually use a ListTile to tell the user that.
// I use a ListTile to create a box with the right height, and put whatever I want on top.
// I could just make a container with the length of a ListTile, but that value could change in the future.
child: Stack(
alignment: Alignment.center,
children: [
ListTile(),
Text(
"Nothing Playing...",
style: TextStyle(color: Colors.grey, fontSize: 18),
)
],
));
}
},
);
}
}
Here's the effect that I'm going for (although I want the whole ListTile to get swiped, not just the song name): https://i.imgur.com/ZapzpJS.mp4
This can be done by using the confirmDismiss callback instead of the onDismiss callback. To make sure that the widget never actually gets dismissed, you need to return false at the end of the function.
Dismissible(
confirmDismiss: (direction) {
...
return false;
}
)

Check / Uncheck ListTiles in ListView.builder() - Flutter

I have a ListView.builder(); in showModalBottomSheet();
Need to select / deselect multiple items on tap everything is well but need to close the modal and show it again to apply changes, another thing is the ListTiles sometimes duplicated more than once, function emptyList doesn't work well.
import 'package:http/http.dart' as http;
import 'dart:convert';
import 'dart:async';
import 'package:flutter/material.dart';
import 'book_details.dart' show BookDetails;
class Explore extends StatefulWidget {
#override
_ExploreState createState() => _ExploreState();
}
var _books,
_categories,
_arranges,
_currentCategory,
_selected,
_primeColor,
_currentFilter,
_isThereIsFilters,
_booksContainer,
_booksWithFilters,
_isLoading,
_noBooks,
_itemIcon;
final GlobalKey<ScaffoldState> _scaffoldKeyExplore =
new GlobalKey<ScaffoldState>();
List<String> _getCats = new List();
List<String> _getArrs = new List();
void _insertCategories() {
for (int i = 0; i < _categories.length; i++) {
_getCats.add(_categories[i]);
}
_getCats.sort();
}
void _insertArranges() {
for (int i = 0; i < _arranges.length; i++) {
_getArrs.add(_arranges[i]);
}
}
class _ExploreState extends State<Explore> with TickerProviderStateMixin {
onCatChange(String category) {
setState(() {
_currentCategory = category;
});
}
#override
void initState() {
super.initState();
_primeColor = Color.fromRGBO(239, 89, 39, 1.0);
_categories = ["أول", "ثاني", "ثالث", "رابع", "خامس"];
_arranges = ["أول", "ثاني", "ثالث", "رابع", "خامس"];
_currentFilter = _arranges[0];
_selected = [];
_isThereIsFilters = false;
}
void emptyList(List list) {
for (var i = 0; i < list.length; i++) {
list.remove(list[i]);
}
}
_showSheet(String type) {
switch (type) {
case "filters":
showModalBottomSheet(
context: _scaffoldKeyExplore.currentContext,
builder: (BuildContext context) {
return Directionality(
textDirection: TextDirection.rtl,
child: Container(
child: Column(children: <Widget>[
Expanded(
child: new ListView.builder(
itemCount: _getArrs[0] != null ? _getArrs.length : 0,
itemBuilder: (BuildContext context, int i) {
return new RadioListTile(
title: Text(_getArrs[i]),
value: _getArrs[i],
groupValue: _currentFilter,
onChanged: (val) {
setState(() {
_currentFilter = val;
});
});
}),
)
])),
);
});
break;
case "categories":
default:
showModalBottomSheet(
context: _scaffoldKeyExplore.currentContext,
builder: (BuildContext context) {
return Directionality(
textDirection: TextDirection.rtl,
child: Container(
child: Column(children: <Widget>[
Container(
color: _primeColor,
child: Row(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
IconButton(
icon: Icon(Icons.close, color: Colors.white),
onPressed: () {
emptyList(_selected);
//Navigator.pop(context);
//_showSheet(type);
}),
IconButton(
icon:
Icon(Icons.done_all, color: Colors.white),
onPressed: () {
if (_selected.length > 0) {
_getFilteredBooks(_selected);
setState(() {
_isThereIsFilters = true;
});
} else {
setState(() {
_isThereIsFilters = false;
});
}
Navigator.pop(context);
})
]),
),
Expanded(
child: new ListView.builder(
itemCount: _getCats != null ? _getCats.length : 0,
itemBuilder: (BuildContext context, int i) {
final _isSelected = _selected.contains(_getCats[i]);
return new ListTile(
leading: Icon(Icons.category),
trailing: _isSelected ? Icon(Icons.done) : null,
title: Text(_getCats[i]),
onTap: () {
setState(() {
_isSelected
? _selected.remove(_getCats[i])
: _selected.add(_getCats[i]);
});
//Navigator.pop(context);
//_showSheet(type);
});
}),
)
])),
);
});
break;
}
}
#override
Widget build(BuildContext context) {
return new Directionality(
textDirection: TextDirection.rtl,
child: new Scaffold(
key: _scaffoldKeyExplore,
appBar:
AppBar(title: Text("استكشاف"), elevation: 0.0, actions: <Widget>[
IconButton(
icon: Icon(Icons.category, color: _primeColor),
onPressed: () => _showSheet("categories")),
IconButton(
icon: Icon(Icons.filter_list, color: _primeColor),
onPressed: () => _showSheet("filters"))
]),
body: Center(child: Text("Nothing..."));
));
}
}
Thank you
need to close the modal and show it again to apply changes
This happens because the showModalBottomSheet's builder needs to be called again to reflect the changes.
In Flutter, StatefulWidgets should be able to rebuild any time the state changes - which is not the case here, because of the bottom sheet being shown.
Why did I run into this issue (on a meta level)?
Storing the state in StatefulWidgets is useful for saving UI state, but you quickly outgrow this technique if you want to store some "app state" or "data state" that is independent of the screen it's on.
It is finally time to fundamentally rethink your state management and settle on a full-fledged state management pattern that decouples the state from the widgets. Luckily, there are a few to choose from:
Making everything global, like you did above. This is generally not a good idea, as you break the contract of setState (state can be modified without the widgets being notified). Also, you break hot restart and stuff like that.
Using an InheritedWidget, where widgets below a root widget can access the same state.
Using a ScopedModel, which builds on top of that.
Using the infamous BLoC pattern, which also builds on top of the InheritedWidget, but adds some Stream-y stuff to make everything more reactive.
Probably many more.
Here is a great Youtube video about state management from Google I/O, where several patterns are being presented.
Anyways, are bottom sheets the right widget for the task ahead?
According to the Material Design spec, the modal bottom sheet is "an alternative to inline menus or simple dialogs on mobile, providing room for additional items, longer descriptions, and iconography".
More concrete, the showModalBottomSheet function is designed to show a widget that doesn't affect the parent over time, but rather - if at all - at a single point in time. That's why it returns a Future<T>, not a Stream<T>.
Be aware that you are trying to use the bottom sheet in a way that it's not intended to be used.
In your case, I'd recommend just using a new screen.