setState() doesn't update constructor values in TabBarView tabs - flutter

Question

I have a TabBarView with two tabs in main widget. First tab includes gridview with cards. Cards use parent widget (MyHomePage) as listener to listen in-card button clicks.
When i click on button in some card, listener impl. must open second Tab and pass selected Excursion to it. But when I do it, at first iteration, ExcursionEditor(currentExcursion) says, that argument is null, but parent build says, that it is not. If I resize my browser, it calls global rebuild and currentExcursion reach last build value.
So, i cant understand, why MyHomePage build doesn't affect on TabBarView content with arguments passed by constructor
class MyHomePage
import 'package:flutter/material.dart';
import 'package:questbuilder/api/content_manager.dart';
import 'package:questbuilder/model/excursion.dart';
import 'package:questbuilder/pages/tab_editor.dart';
import 'package:questbuilder/pages/tab_my_excursions.dart';
import 'package:questbuilder/widgets/excursion_preview_card.dart';
import 'package:logger/logger.dart';
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage>
with TickerProviderStateMixin
implements ExcursionCardInteractionListener {
Logger logger = Logger();
Excursion currentExcursion;
TabController tabController;
#override
void initState() {
super.initState();
print("INIT STATE FOR HOME PAGE");
tabController = TabController(vsync: this, length: 2);
}
#override
Widget build(BuildContext context) {
var screenSize = MediaQuery.of(context).size;
print("HOME PAGE BUILD currentExcursion = ${currentExcursion?.toJson()}");
return Scaffold(
extendBodyBehindAppBar: true,
appBar: PreferredSize(
preferredSize: Size(screenSize.width, 1000),
child: Container(
color: Colors.black,
child: Padding(
padding: EdgeInsets.fromLTRB(10, 10, 30, 0),
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: [
Row(children: [
Padding(
padding: EdgeInsets.fromLTRB(10, 0, 10, 10),
child: Text('QUESTBUILDER',
style: TextStyle(color: Colors.white))),
SizedBox(width: screenSize.width / 20),
Container(
width: screenSize.width / 6,
child: TabBar(
labelPadding: EdgeInsets.fromLTRB(10, 0, 10, 10),
indicatorColor: Colors.white,
controller: tabController,
tabs: [
Tab(text: "Мои экскурсии"),
Tab(text: "Редактор"),
]))
]),
Padding(
padding: EdgeInsets.fromLTRB(0, 0, 0, 10),
child: Row(
children: [
FlatButton.icon(
label: Text("Создать экскурсию"),
icon: Icon(Icons.add),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(40.0)),
textColor: Colors.white,
color: Colors.green,
onPressed: () {
createExcursion();
}),
SizedBox(
width: 40,
),
InkWell(
onTap: () {},
child: Text(
'Вход',
style: TextStyle(color: Colors.white),
),
)
],
)),
],
),
),
),
),
body: Padding(
padding: EdgeInsets.all(15),
child: TabBarView(
controller: tabController,
children: [
// Set listener to cards in this widget to prerform 'edit' clicks
MyExcursionsTab(this),
ExcursionEditor(currentExcursion)
],
)));
}
// Here i call setState from cards
#override
void editExcursion(Excursion excursion) {
setState(() {
currentExcursion = excursion;
});
tabController.animateTo(1);
}
#override
void dispose() {
tabController.dispose();
super.dispose();
}
void createExcursion() {
ContentManager.client.createExcursion(0).then((value) {
currentExcursion = value;
editExcursion(currentExcursion);
});
}
}
class ExcursionEditor
import 'dart:typed_data';
import 'package:file_picker/file_picker.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:questbuilder/api/content_manager.dart';
import 'package:questbuilder/model/excursion.dart';
import 'package:questbuilder/model/excursion_content.dart';
import 'package:questbuilder/model/excursion_data.dart';
import 'package:questbuilder/model/picture.dart';
class ExcursionEditor extends StatefulWidget {
Excursion excursion;
ExcursionEditor(this.excursion);
#override
State<StatefulWidget> createState() => ExcursionEditorState();
}
class ExcursionEditorState extends State<ExcursionEditor> {
ExcursionData currentData;
ExcursionContent currentContent;
Excursion excursion;
List<Picture> pictures = [];
#override
void initState() {
super.initState();
print("INIT EDITOR widget.excrusion = ${widget.excursion?.toJson()}");
// At this point, after call setState() in HomePage widget.excrusion is always null
// until I resize browser, thereby calling global state reset
//
if (widget.excursion != null)
ContentManager.client.getPictureList(widget.excursion.id).then((value) {
pictures.addAll(value);
print(pictures);
});
}
#override
Widget build(BuildContext context) {
excursion = widget.excursion;
print("BUILD EDITOR excursion = ${widget.excursion?.toJson()}");
return excursion != null
? Container()
: Container(
child: Align(
alignment: Alignment.center,
child: Text("Выберите экскурсию для редактирования")));
}
}
Log of first launch and card click build sequence:
HOME PAGE BUILD currentExcursion = null
HOME PAGE BUILD currentExcursion = {id: 1}
INIT EDITOR widget.excrusion = null
BUILD EDITOR excursion = null
After browser window resize
HOME PAGE BUILD currentExcursion = {id: 1}
BUILD EDITOR excursion = {id: 1}
BUILD EDITOR excursion = {id: 1}
HOME PAGE BUILD currentExcursion = {id: 1}
BUILD EDITOR excursion = {id: 1}
After screen resize problem still appear, just replacing null value in editor with old Excursion. New clicks on cards doesn't have effect, setState in callback still not update.
I've tried to bind it on static stream listeners, on TabController listener - it just look like TabBarView late for 1 build cycle of arguments update. Maybe there are some similar questions, but i've done all from thouse answers and got nothing

Answer 1

I am not really sure, but it seems like race condition between setState and _tabController.animateTo(1); because they both try to rebuild the child ExcursionEditor(currentExcursion)
If you print the excursion in ExcursionEditor constructor, you will see the updated value. But at the end the value not reach the build function.
The simple workaround is changing editExcursion to the async function and add a small delay between this 2 actions. Otherwise you can try to use other way to pass data between widgets (like provider)
#override
Future editExcursion(Excursion excursion) async {
setState(() {
currentExcursion = excursion;
});
await Future.delayed(Duration(milliseconds:50));
tabController.animateTo(1);
}