I want to Create an TextField at the bottom of the page like message app.
There is also a IconButton, which adds the entered text into ListView if TextField is not empty. If it is empty then it will show error in SnackBar.
The Problem is the SnackBar stacks on top of TextField. But I want it to be either top or bottom of TextField.
import 'package:flutter/material.dart';
Future<void> main() async {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MainPage(),
);
}
}
class MainPage extends StatefulWidget {
#override
_MainPageState createState() => _MainPageState();
}
class _MainPageState extends State<MainPage> {
final _textList = <String>[];
TextEditingController _textController;
bool _addText(context, String text) {
print(text);
if (text?.isNotEmpty == true) {
setState(() {
_textList.add(text);
});
return true;
} else {
Scaffold.of(context).showSnackBar(
SnackBar(
content: Text("Invalid Text Entered"),
behavior: SnackBarBehavior.fixed,
),
);
return false;
}
}
#override
void initState() {
_textController = TextEditingController();
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Demo"),
),
body: SafeArea(
child: Column(
children: <Widget>[
Expanded(
child: ListView.separated(
itemCount: _textList.length,
separatorBuilder: (_, __) => Divider(height: 1.0),
itemBuilder: (context, index) => ListTile(
title: Text("${_textList[index]}"),
),
),
),
_buildBottom(),
],
),
),
);
}
Widget _buildBottom() {
return Material(
elevation: 5.0,
color: Colors.blue[100],
child: Row(
children: <Widget>[
Expanded(
child: TextField(
controller: _textController,
decoration: InputDecoration(
hintText: "Enter Text",
contentPadding: EdgeInsets.symmetric(horizontal: 10.0),
border: InputBorder.none,
),
),
),
Builder(
builder: (context) => IconButton(
icon: Icon(Icons.add),
onPressed: () {
final success = _addText(context, _textController.text);
if (success) _textController.clear();
},
),
),
],
),
);
}
}
This is my code in DartPad
try this,
import 'package:flutter/material.dart';
Future<void> main() async {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: MainPage(),
);
}
}
class MainPage extends StatefulWidget {
#override
_MainPageState createState() => _MainPageState();
}
class _MainPageState extends State<MainPage> {
final _textList = <String>[];
TextEditingController _textController;
bool isVisible = false;
bool _addText(context, String text) {
print(text);
if (text?.isNotEmpty == true) {
setState(() {
_textList.add(text);
});
return true;
} else {
Scaffold.of(context).showSnackBar(
new SnackBar(
content: Text("Invalid Text Entered"),
behavior: SnackBarBehavior.fixed,
duration: Duration(seconds: 3),
onVisible: (() {
setState(() {
isVisible = true;
});
Future.delayed(Duration(seconds: 3)).then((_) => setState(() {
isVisible = false;
}));
}),
),
);
return false;
}
}
#override
void initState() {
_textController = TextEditingController();
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Demo"),
),
body: SafeArea(
child: Column(
children: <Widget>[
Expanded(
child: ListView.separated(
itemCount: _textList.length,
separatorBuilder: (_, __) => Divider(height: 1.0),
itemBuilder: (context, index) => ListTile(
title: Text("${_textList[index]}"),
),
),
),
AnimatedContainer(
margin: EdgeInsets.only(bottom: isVisible ? 50 : 0),
child: _buildBottom(),
duration: Duration(milliseconds: 100),
),
],
),
),
);
}
Widget _buildBottom() {
return Material(
elevation: 5.0,
color: Colors.blue[100],
child: Row(
children: <Widget>[
Expanded(
child: TextField(
controller: _textController,
decoration: InputDecoration(
hintText: "Enter Text",
contentPadding: EdgeInsets.symmetric(horizontal: 10.0),
border: InputBorder.none,
),
),
),
Builder(
builder: (context) => IconButton(
icon: Icon(Icons.add),
onPressed: () {
final success = _addText(context, _textController.text);
if (success) _textController.clear();
},
),
),
],
),
);
}
}
Perhaps using Flushbar might help with your problem. There are many properties that you can change, such as flushbarPosition.
It might not solve your problem exactly how you would expect it to but it can make the Flushbar appear from the top instead of the bottom and that's one way around your problem
Flushbar: https://pub.dev/packages/flushbar
I think the best thing you can do here is to change the behaviour to floating
SnackBar(
behavior: SnackBarBehavior.floating,
...
Related
`I want to access the provider in the AddRecipe page in order to save a new recipe and notify the listeners, in my case the list.builder in UserRecipes to rebuild.
Sorry for the big amount of code, I added everything that I thought may be useful. I just can't figure it out, have been trying for hours.
This is the error that I get:
ProviderNotFoundException (Error: Could not find the correct Provider<RecipeProvider> above this AddRecipe Widget
These are the files:
Wrapper.dart:
class Wrapper extends StatelessWidget {
const Wrapper({super.key});
#override
Widget build(BuildContext context) {
final user = Provider.of<User?>(context);
if (user == null) {
return const AuthPage();
} else {
return MultiProvider(
providers: [
ChangeNotifierProvider(create: (_) => RecipeProvider(uid: user.uid))
],
child: const HomePage()
);
}
}
}
Home.dart:
class HomePage extends StatefulWidget {
const HomePage({super.key});
#override
State<HomePage> createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
final AuthService _auth = AuthService();
// The 4 main application screens
static const List<Destination> allDestinations = <Destination>[
Destination(0, 'Home', Icons.home, Colors.teal),
Destination(1, 'Meals', Icons.dinner_dining, Colors.orange),
Destination(2, 'Recipes', Icons.restaurant_menu_sharp, Colors.amber),
Destination(3, 'Profile', Icons.person, Colors.blue),
];
int currentPageIndex = 0;
final screens = [
Center(child: Text('Home'),),
Center(child: Text('Meals'),),
RecipesPage(),
Center(child: Text('My profile'),),
];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: CustomAppBar(title: allDestinations[currentPageIndex].title, backButton: false, signOutButton: true),
bottomNavigationBar: NavigationBar(
onDestinationSelected: (int index) {
setState(() {
currentPageIndex = index;
});
},
selectedIndex: currentPageIndex,
destinations: allDestinations.map((Destination destination) {
return NavigationDestination(
icon: Icon(destination.icon, color: destination.color),
label: destination.title
);
}).toList(),
),
body: screens[currentPageIndex]
);
}
}
class Destination {
const Destination(this.index, this.title, this.icon, this.color);
final int index;
final String title;
final IconData icon;
final MaterialColor color;
}
Recipes.dart:
const List<Widget> recipes = <Widget>[
Text('My recipes'),
Text('Other recipes')
];
class RecipesPage extends StatefulWidget {
const RecipesPage({super.key});
#override
State<RecipesPage> createState() => _RecipesPageState();
}
class _RecipesPageState extends State<RecipesPage> {
final List<bool> _selectedRecipes = <bool>[true, false];
final _searchContoller = TextEditingController();
#override
void dispose() {
_searchContoller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
var provider = context.watch<RecipeProvider>();
return Scaffold(
body: SafeArea(
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
SizedBox(height: 20),
ToggleButtons(
direction: Axis.horizontal,
onPressed: (int index) {
setState(() {
for (int i = 0; i < _selectedRecipes.length; i++) {
_selectedRecipes[i] = i == index;
}
});
},
borderRadius: const BorderRadius.all(Radius.circular(12)),
selectedBorderColor: Colors.blue[700],
selectedColor: Colors.white,
fillColor: Colors.blue[200],
color: Colors.blue[400],
constraints: const BoxConstraints(
minHeight: 40.0,
minWidth: 165.0,
),
isSelected: _selectedRecipes,
children: recipes
),
SizedBox(height: 10),
// Search textfield
Padding(
padding: const EdgeInsets.symmetric(horizontal: 30.0),
child: TextField(
controller: _searchContoller,
decoration: InputDecoration(
enabledBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.white),
borderRadius: BorderRadius.circular(12),
),
focusedBorder: OutlineInputBorder(
borderSide: BorderSide(color: Colors.blue),
borderRadius: BorderRadius.circular(12),
),
hintText: 'Search',
fillColor: Colors.grey[250],
filled: true
),
),
),
SizedBox(height: 20),
Expanded(
child: _getRecipePage(),
),
],
)
),
),
floatingActionButton: Consumer<RecipeProvider>(
builder: (context, value, child) {
return _getFAB();
},
)
);
}
Widget _getFAB() {
if (_selectedRecipes[1]) {
return Container();
} else {
return FloatingActionButton(
child: Icon(Icons.add, size: 35),
onPressed: () => {
Navigator.of(context).push(
MaterialPageRoute(
builder: (_) => AddRecipe()
)
),
},
);
}
}
Widget _getRecipePage() {
if (_selectedRecipes[0]) {
return UserRecipesWidget(search: _searchContoller.text.trim());
} else {
return OtherRecipesWidget();
}
}
}
User_recipes.dart:
class UserRecipesWidget extends StatefulWidget {
UserRecipesWidget({super.key, required this.search});
String search;
#override
State<UserRecipesWidget> createState() => _UserRecipesWidgetState();
}
class _UserRecipesWidgetState extends State<UserRecipesWidget> {
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
var provider = context.watch<RecipeProvider>();
return FutureBuilder(
future: provider.getUserRecipesFuture,
builder: (BuildContext ctx, AsyncSnapshot asyncSnapshot) {
if (asyncSnapshot.connectionState == ConnectionState.done) {
if (asyncSnapshot.hasError) {
return const Center(child: Text('Could not retreive recipes!'));
}
return ListView.builder(
itemCount: provider.recipes.length,
itemBuilder: (BuildContext ctx, int index) {
return GestureDetector(
onTap: () => {
Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => RecipePage(recipe: provider.recipes[index])
)
),
},
child: RecipeCard(recipe: provider.recipes[index]),
);
}
);
} else {
return Center(child: CircularProgressIndicator());
}
}
);
}
}
RecipeProvider:
class RecipeProvider extends ChangeNotifier {
late RecipeService _recipeService;
List<RecipeModel> recipes = [];
late Future getUserRecipesFuture;
final String uid;
RecipeProvider({ required this.uid }) {
_recipeService = RecipeService(uid: uid);
getUserRecipesFuture = _getUserRecipesFuture();
}
Future _getUserRecipesFuture() async {
recipes = await _recipeService.getUserRecipes();
addDummyRecipe();
}
addDummyRecipe() {
recipes.add(RecipeModel(uid: "test", userId: "test", recipeName: "Pork"));
recipes.add(RecipeModel(uid: "test1", userId: "test1", recipeName: "Pizza"));
recipes.add(RecipeModel(uid: "test2", userId: "test2", recipeName: "Burger"));
notifyListeners();
}
}
And the main one that gives the error, add_recipe.dart:
class AddRecipe extends StatefulWidget {
const AddRecipe({super.key});
#override
State<AddRecipe> createState() => _AddRecipeState();
}
class _AddRecipeState extends State<AddRecipe> {
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: CustomAppBar(title: 'Add recipe', backButton: true),
body: SafeArea(
child: Center(
child: Column(
children: [
Text('Add recipe'),
SizedBox(height: 50),
// Add recipe button
Padding(
padding: const EdgeInsets.symmetric(horizontal: 30.0),
child: GestureDetector(
onTap: () async {
context.read<RecipeProvider>().addDummyRecipe();
},
child: Container(
padding: EdgeInsets.all(16),
decoration: BoxDecoration(
color: Colors.green,
borderRadius: BorderRadius.circular(12),
),
child: Center(
child: Text(
'Save recipe',
style: TextStyle(
color: Colors.white,
fontWeight: FontWeight.bold,
fontSize: 20,
),
),
),
),
),
),
]
)
)
),
);
}
}
`
the exception happens because you provided the RecipeProvider only for the HomePage(). means when you push a new route, it doesn't have that the RecipeProvider instance.
if you can't provide the RecipeProvider Golobally because it needs the uid, then you must provide it each time you push a new route
change your RecipePage Navigator to this
Navigator.of(context).push(
MaterialPageRoute(
builder: (_) => ChangeNotifierProvider.value(
value: context.read<RecipeProvider>(),
child: RecipePage(recipe: provider.recipes[index]),
),
),
),
and your AddRecipe
Navigator.of(context).push(
MaterialPageRoute(
builder: (_) => ChangeNotifierProvider.value(
value: context.read<RecipeProvider>(),
child: AddRecipe(),
),
),
),
for many of you this is an obvious / stupid question, but I've come to a point where I don't have a clue anymore. I have real difficulties understanding State Management with Bloc / Cubit.
Expectation: I have a page with a ListView (recipe_list) of all recipes and an 'add' button. Whenever I click on a ListItem or the 'add' button I go to the next page (recipe_detail). On this page I can create a new recipe (if clicked the 'add' button before), update or delete the existing recipe (if clicked on ListItem before). When I click the 'save' or 'delete' button the Navigator pops and I go back to the previous page (recipe_list). I used Cubit to manage the state of the recipe list. My expectation is that the ListView updates automatically after I clicked 'save' or 'delete'. But I have to refresh the App to display the changes.
main.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(
debugShowCheckedModeBanner: false,
title: 'Recipe Demo',
home: BlocProvider<RecipeCubit>(
create: (context) => RecipeCubit(RecipeRepository())..getAllRecipes(),
child: const RecipeList(),
)
);
}
}
recipe_list.dart
class RecipeList extends StatefulWidget {
const RecipeList({Key? key}) : super(key: key);
#override
_RecipeListState createState() => _RecipeListState();
}
class _RecipeListState extends State<RecipeList> {
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Container(
padding: const EdgeInsets.symmetric(
horizontal: 24.0
),
color: const Color(0xFFF6F6F6),
child: Stack(
children: [
Column(
children: [
Container(
margin: const EdgeInsets.only(
top: 32.0,
bottom: 32.0
),
child: const Center(
child: Text('Recipes'),
),
),
Expanded(
child: BlocBuilder<RecipeCubit, RecipeState>(
builder: (context, state) {
if (state is RecipeLoading) {
return const Center(
child: CircularProgressIndicator(),
);
} else if (state is RecipeError) {
return const Center(
child: Icon(Icons.close),
);
} else if (state is RecipeLoaded) {
final recipes = state.recipes;
return ListView.builder(
itemCount: recipes.length,
itemBuilder: (context, index) {
return GestureDetector(
onTap: () {
Navigator.push(context, MaterialPageRoute(
builder: (context) {
return BlocProvider<RecipeCubit>(
create: (context) => RecipeCubit(RecipeRepository()),
child: RecipeDetail(recipe: recipes[index]),
);
}
));
},
child: RecipeCardWidget(
title: recipes[index].title,
description: recipes[index].description,
),
);
},
);
} else {
return const Text('Loading recipes error');
}
}
),
),
],
),
Positioned(
bottom: 24.0,
right: 0.0,
child: FloatingActionButton(
heroTag: 'addBtn',
onPressed: () {
Navigator.push(context, MaterialPageRoute(
builder: (context) {
return BlocProvider<RecipeCubit>(
create: (context) => RecipeCubit(RecipeRepository()),
child: const RecipeDetail(recipe: null),
);
}
));
},
child: const Icon(Icons.add_rounded),
backgroundColor: Colors.teal,
),
)
],
),
),
),
);
}
}
recipe_detail.dart
class RecipeDetail extends StatefulWidget {
final Recipe? recipe;
const RecipeDetail({Key? key, required this.recipe}) : super(key: key);
#override
_RecipeDetailState createState() => _RecipeDetailState();
}
class _RecipeDetailState extends State<RecipeDetail> {
final RecipeRepository recipeRepository = RecipeRepository();
final int _recipeId = 0;
late String _recipeTitle = '';
late String _recipeDescription = '';
final recipeTitleController = TextEditingController();
final recipeDescriptionController = TextEditingController();
late FocusNode _titleFocus;
late FocusNode _descriptionFocus;
bool _buttonVisible = false;
#override
void initState() {
if (widget.recipe != null) {
_recipeTitle = widget.recipe!.title;
_recipeDescription = widget.recipe!.description;
_buttonVisible = true;
}
_titleFocus = FocusNode();
_descriptionFocus = FocusNode();
super.initState();
}
#override
void dispose() {
recipeTitleController.dispose();
recipeDescriptionController.dispose();
_titleFocus.dispose();
_descriptionFocus.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: SafeArea(
child: Container(
padding: const EdgeInsets.symmetric(
horizontal: 24.0
),
color: const Color(0xFFF6F6F6),
child: Stack(
children: [
Column(
children: [
Align(
alignment: Alignment.topLeft,
child: InkWell(
child: IconButton(
highlightColor: Colors.transparent,
color: Colors.black54,
onPressed: () {
Navigator.pop(context);
},
icon: const Icon(Icons.arrow_back_ios_new_rounded),
),
),
),
TextField(
focusNode: _titleFocus,
controller: recipeTitleController..text = _recipeTitle,
decoration: const InputDecoration(
hintText: 'Enter recipe title',
border: InputBorder.none
),
style: const TextStyle(
fontSize: 26.0,
fontWeight: FontWeight.bold
),
onSubmitted: (value) => _descriptionFocus.requestFocus(),
),
TextField(
focusNode: _descriptionFocus,
controller: recipeDescriptionController..text = _recipeDescription,
decoration: const InputDecoration(
hintText: 'Enter recipe description',
border: InputBorder.none
),
),
],
),
Positioned(
bottom: 24.0,
left: 0.0,
child: FloatingActionButton(
heroTag: 'saveBtn',
onPressed: () {
if (widget.recipe == null) {
Recipe _newRecipe = Recipe(
_recipeId,
recipeTitleController.text,
recipeDescriptionController.text
);
context.read<RecipeCubit>().createRecipe(_newRecipe);
//recipeRepository.createRecipe(_newRecipe);
Navigator.pop(context);
} else {
Recipe _newRecipe = Recipe(
widget.recipe!.id,
recipeTitleController.text,
recipeDescriptionController.text
);
context.read<RecipeCubit>().updateRecipe(_newRecipe);
//recipeRepository.updateRecipe(_newRecipe);
Navigator.pop(context);
}
},
child: const Icon(Icons.save_outlined),
backgroundColor: Colors.amberAccent,
),
),
Positioned(
bottom: 24.0,
right: 0.0,
child: Visibility(
visible: _buttonVisible,
child: FloatingActionButton(
heroTag: 'deleteBtn',
onPressed: () {
context.read<RecipeCubit>().deleteRecipe(widget.recipe!.id!);
//recipeRepository.deleteRecipe(widget.recipe!.id!);
Navigator.pop(context);
},
child: const Icon(Icons.delete_outline_rounded),
backgroundColor: Colors.redAccent,
),
),
),
],
),
),
),
);
}
}
recipe_state.dart
part of 'recipe_cubit.dart';
abstract class RecipeState extends Equatable {
const RecipeState();
}
class RecipeInitial extends RecipeState {
#override
List<Object> get props => [];
}
class RecipeLoading extends RecipeState {
#override
List<Object> get props => [];
}
class RecipeLoaded extends RecipeState {
final List<Recipe> recipes;
const RecipeLoaded(this.recipes);
#override
List<Object> get props => [recipes];
}
class RecipeError extends RecipeState {
final String message;
const RecipeError(this.message);
#override
List<Object> get props => [message];
}
recipe_cubit.dart
part 'recipe_state.dart';
class RecipeCubit extends Cubit<RecipeState> {
final RecipeRepository recipeRepository;
RecipeCubit(this.recipeRepository) : super(RecipeInitial()) {
getAllRecipes();
}
void getAllRecipes() async {
try {
emit(RecipeLoading());
final recipes = await recipeRepository.getAllRecipes();
emit(RecipeLoaded(recipes));
} catch (e) {
emit(const RecipeError('Error'));
}
}
void createRecipe(Recipe recipe) async {
await recipeRepository.createRecipe(recipe);
final newRecipes = await recipeRepository.getAllRecipes();
emit(RecipeLoaded(newRecipes));
}
void updateRecipe(Recipe recipe) async {
await recipeRepository.updateRecipe(recipe);
final newRecipes = await recipeRepository.getAllRecipes();
emit(RecipeLoaded(newRecipes));
}
void deleteRecipe(int id) async {
await recipeRepository.deleteRecipe(id);
final newRecipes = await recipeRepository.getAllRecipes();
emit(RecipeLoaded(newRecipes));
}
}
It looks like you're creating another BlocProvider when you're navigating to RecipeDetail page. When you're pushing new MaterialPageRoute, this new page gets additionally wrapped in new RecipeCubit. Then, when you're calling context.read<RecipeCubit>(), you're referencing that provider (as this is closest BlocProvider in the widget tree). Your RecipeList can't react to those changes because it's BlocBuilder is looking for a BlocProvider declared above it in the widget tree (the one in MyApp).
Besides that, newly created provider gets removed from the widget tree anyway when you're closing RecipeDetail page as it is declared in the MaterialPageRoute which has just been pushed off the screen.
Try to remove the additional BlocProvider (the one in RecipeList, in OnTap function of RecipeCardWidget):
onTap: () {
Navigator.push(context, MaterialPageRoute(
builder: (context) {
return BlocProvider<RecipeCubit>( // remove this BlocProvider
create: (context) => RecipeCubit(RecipeRepository()),
child: RecipeDetail(recipe: recipes[index]),
);
}
));
},
I have the following cart screen which contains the address fields. When a user wants to update their address, they click on Update button, which takes them to the address screen where they can update the address. Although when the back button is clicked to return back to the cart screen,the print function shows the updated value but the UI still shows the old value.
class CartScreen extends StatefulWidget {
static const routeName = '/cart';
#override
_CartScreenState createState() => _CartScreenState();
}
class _CartScreenState extends State<CartScreen> {
Future _addressFuture;
String value = 'deliver';
var address;
void initState() {
_addressFuture = _obtainAddressFuture();
super.initState();
}
Future _obtainAddressFuture() async {
address = await Provider.of<Addresses>(context, listen: false).fetchMyAddress();
}
void didChangeDependencies() async {
print('inside didchange');
super.didChangeDependencies();
}
#override
void dispose() {
super.dispose();
}
#override
Widget build(BuildContext context) {
print('Rebuild cart');
return GestureDetector(
child: Scaffold(
appBar: AppBar(
title: Text('Your Cart'),
),
body: FutureBuilder(
future: _addressFuture,
builder: (ctx, dataSnapshot) {
if (dataSnapshot.error != null) {
print('Data snapshot error is ' +
dataSnapshot.error.toString());
return Center(
child: Text('Something went wrong!'),
);
} else if (dataSnapshot.connectionState ==
ConnectionState.waiting) {
return Center(
child: Loading(),
);
} else {
return Container(
child: SingleChildScrollView(
child: Column(
children: [
Card(
margin: EdgeInsets.symmetric(
horizontal: 15,
vertical: 4,
),
child: Column(
children: [
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
new GestureDetector(
onTap: () async{
_awaitReturnValueFromSecondScreen(context);
},
child: Container(
padding: EdgeInsets.all(10),
child: const Text("Update",
style: TextStyle(
color: Colors.blue))),
)
],
),
TextFormField(
initialValue: address.name,
readOnly: true,
decoration: InputDecoration(
border: InputBorder.none,
prefixIcon: Icon(Icons.person,
color: Colors.orangeAccent),
labelText: 'Contact name'),
),
],
)),
],
)));
}
})));
}
void _awaitReturnValueFromSecondScreen(BuildContext context) async {
// start the SecondScreen and wait for it to finish with a result
final result = await Navigator.push(
context,
MaterialPageRoute(
builder: (context) => AddressScreen('cartScreen'),
));
setState(() {
address = result;
});
print(address.name);
}
}
please check the below example as it requires async and await to get the data from 2nd screen
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
void main() => runApp(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 Location',
theme: ThemeData(
primarySwatch: Colors.amber,
),
home: Provider(
create: (context) => Addresses(),
child: CartScreen(),
),
);
}
}
class CartScreen extends StatefulWidget {
static const routeName = '/cart';
#override
_CartScreenState createState() => _CartScreenState();
}
class _CartScreenState extends State<CartScreen> {
Future? _addressFuture;
String value = 'deliver';
var address;
void initState() {
_addressFuture = _obtainAddressFuture();
super.initState();
}
Future _obtainAddressFuture() async {
address =
await Provider.of<Addresses>(context, listen: false).fetchMyAddress();
}
void didChangeDependencies() async {
super.didChangeDependencies();
}
#override
void dispose() {
super.dispose();
}
#override
Widget build(BuildContext context) {
return GestureDetector(
child: Scaffold(
appBar: AppBar(
title: Text('Your Cart'),
),
body: FutureBuilder(
future: _addressFuture,
builder: (ctx, dataSnapshot) {
if (dataSnapshot.error != null) {
print('Data snapshot error is ' + dataSnapshot.error.toString());
return const Center(
child: Text('Something went wrong!'),
);
} else if (dataSnapshot.connectionState ==
ConnectionState.waiting) {
return const Center(
child: CircularProgressIndicator(),
);
} else {
return SingleChildScrollView(
child: Column(
children: [
Card(
margin: const EdgeInsets.symmetric(
horizontal: 15,
vertical: 4,
),
child: Column(
children: [
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
GestureDetector(
onTap: () async {
// Here you have to wait for the screen to retrun data so we use asyn await
final result = await Navigator.push(
context,
MaterialPageRoute(
builder: (_) =>
AddressScreen(title: 'cartScreen'),
),
);
print(result);
},
child: Container(
padding: EdgeInsets.all(10),
child: const Text(
"Update",
style: TextStyle(
color: Colors.blue,
),
),
),
)
],
),
TextFormField(
// initialValue: address.name,
readOnly: true,
decoration: InputDecoration(
border: InputBorder.none,
prefixIcon: Icon(Icons.person,
color: Colors.orangeAccent),
labelText: 'Contact name',
),
),
],
),
),
],
),
);
}
},
),
),
);
}
}
class AddressScreen extends StatelessWidget {
const AddressScreen({
Key? key,
required this.title,
}) : super(key: key);
final String title;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(title),
),
body: Center(
child: TextButton(
onPressed: () {
// Here you have pass the data that you want
Navigator.pop(context, 'Data pass here ');
},
child: Text('Pass data back'),
),
),
);
}
}
class Addresses {
Future fetchMyAddress() async {}
}
I am stuck here for the past 20 days in returning data in my app from the other screen. I'm new to programming and need help. I've been searching through all the internet to find an answer related to my query but nothing is helping though. I ask my fellow SO guys to please help.
You can look at the entire code which I've made open here.
My code:
class SecondPage extends StatefulWidget {
#override
_SecondPageState createState() => _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
#override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.all(30),
child: Stack(
alignment: Alignment.bottomRight,
children: <Widget>[
FloatingActionButton(
child: Icon(
Icons.add,
color: Colors.blue,
),
onPressed: () async {
final newList = await Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FavoriteList(),
),
);
setState(() {
return ListView.builder(
itemCount: newList.length,
itemBuilder: (context, index){
return Container(
child: Text('item: $newList'),
);
},
);
});
},
)
],
),
);
}
}
The screen where Navigator.pop() is used:
final Set saved = Set();
class FavoriteList extends StatefulWidget {
#override
_FavoriteListState createState() => _FavoriteListState();
}
class _FavoriteListState extends State<FavoriteList> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Add to Favorites!'),
centerTitle: true,
backgroundColor: Colors.red),
body: SafeArea(
child: ListView.builder(
itemCount: 53,
itemBuilder: (context, index) {
return CheckboxListTile(
activeColor: Colors.red,
checkColor: Colors.white,
value: saved.contains(index),
onChanged: (val) {
setState(() {
// isChecked = val; // changed
// if(val == true){ // changed
// __saved.add(context); // changed
// } else{ // changed
// __saved.remove(context); // changed
// } // changed
if (val == true) {
saved.add(index);
} else {
saved.remove(index);
}
});
},
title: Row(
children: <Widget>[
Image.asset('lib/images/${images[index]}'),
SizedBox(
width: 10,
),
Text(nameOfSite[index]),
],
),
);
},
),
),
floatingActionButton: FloatingActionButton(
foregroundColor: Colors.red,
child: Icon(Icons.check),
onPressed: () {
Navigator.pop<Set>(context, saved);
},
),
);
}
}
Here is the SecondPage and FavoriteList that I made
import 'package:flutter/material.dart';
import 'package:aioapp2/lists.dart';
Set<int> favorites = {};
class SecondPage extends StatefulWidget {
#override
_SecondPageState createState() => _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
#override
Widget build(BuildContext context) {
return Stack(
fit: StackFit.expand,
children: <Widget>[
_getFavoriteList(),
Align(
alignment: Alignment.bottomRight,
child: Padding(
padding: const EdgeInsets.all(20.0),
child: FloatingActionButton(
child: Icon(
Icons.edit,
color: Colors.blue,
),
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => EditFavorites(),
),
).then((updatedFavorites) {
if (updatedFavorites != null)
setState(() {
favorites = updatedFavorites;
});
});
},
),
),
)
],
);
}
Widget _getFavoriteList() {
if (favorites?.isNotEmpty == true)
return _FavoriteList();
else
return _EmptyFavoriteList();
}
}
class _EmptyFavoriteList extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Flexible(
child: SingleChildScrollView(
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'Add Your Favorite Sites Here!❤',
style: TextStyle(color: Colors.white),
),
Icon(
Icons.favorite,
size: 150,
color: Colors.blue[100],
),
],
),
),
),
),
],
);
}
}
class _FavoriteList extends StatelessWidget {
#override
Widget build(BuildContext context) {
return ListView.builder(
itemCount: favorites.length,
itemBuilder: (context, index) {
return ListTile(
leading: CircleAvatar(
backgroundImage: AssetImage('lib/images/${images[index]}'),
),
title: Text(nameOfSite[favorites.elementAt(index)]),
);
},
);
}
}
//Its FavoriteList Page. I changed the name
class EditFavorites extends StatefulWidget {
#override
_EditFavoritesState createState() => _EditFavoritesState();
}
class _EditFavoritesState extends State<EditFavorites> {
final _editableFavorites = <int>{};
#override
void initState() {
_editableFavorites.addAll(favorites);
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Add to Favorites!'),
centerTitle: true,
backgroundColor: Colors.red,
actions: <Widget>[
IconButton(
icon: Icon(Icons.done),
onPressed: () {
Navigator.pop<Set>(context, _editableFavorites);
},
)
],
),
//backgroundColor: Colors.indigo,
body: SafeArea(
child: ListView.builder(
itemCount: nameOfSite.length,
itemBuilder: (context, index) {
return ListTile(
leading: CircleAvatar(
backgroundImage: AssetImage('lib/images/${images[index]}'),
),
title: Text(nameOfSite[index]),
trailing: IconButton(
icon: _editableFavorites.contains(index)
? Icon(
Icons.favorite,
color: Colors.red,
)
: Icon(
Icons.favorite_border,
color: Colors.grey,
),
onPressed: () {
setState(() {
if (_editableFavorites.contains(index))
_editableFavorites.remove(index);
else
_editableFavorites.add(index);
});
},
),
);
},
),
),
);
}
}
Just replace secondtab.dart with this code.
You can copy paste run full code below
You have to move out return ListView to the same layer with FloatingActionButton
working demo
full code
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: SecondPage(),
);
}
}
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>[
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.display1,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
class SecondPage extends StatefulWidget {
#override
_SecondPageState createState() => _SecondPageState();
}
class _SecondPageState extends State<SecondPage> {
Set newList = {};
#override
Widget build(BuildContext context) {
return Container(
padding: EdgeInsets.all(30),
child: Stack(
alignment: Alignment.bottomRight,
children: <Widget>[
ListView.builder(
itemCount: newList.length,
itemBuilder: (context, index) {
return Container(
child: Text('item: ${newList.elementAt(index)}'),
);
},
),
FloatingActionButton(
child: Icon(
Icons.add,
color: Colors.blue,
),
onPressed: () async {
newList = await Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FavoriteList(),
),
);
setState(() {});
},
)
],
),
);
}
}
final Set saved = Set();
class FavoriteList extends StatefulWidget {
#override
_FavoriteListState createState() => _FavoriteListState();
}
class _FavoriteListState extends State<FavoriteList> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Add to Favorites!'),
centerTitle: true,
backgroundColor: Colors.red),
body: SafeArea(
child: ListView.builder(
itemCount: 53,
itemBuilder: (context, index) {
return CheckboxListTile(
activeColor: Colors.red,
checkColor: Colors.white,
value: saved.contains(index),
onChanged: (val) {
setState(() {
// isChecked = val; // changed
// if(val == true){ // changed
// __saved.add(context); // changed
// } else{ // changed
// __saved.remove(context); // changed
// } // changed
if (val == true) {
saved.add(index);
} else {
saved.remove(index);
}
});
},
title: Row(
children: <Widget>[
//Image.asset('lib/images/${images[index]}'),
SizedBox(
width: 10,
),
Text('nameOfSite[index]'),
],
),
);
},
),
),
floatingActionButton: FloatingActionButton(
foregroundColor: Colors.red,
child: Icon(Icons.check),
onPressed: () {
Navigator.pop<Set>(context, saved);
},
),
);
}
}
I have a form widget, a list widget, and a "wrapper" widget or in other words, a parent/container widget. So to give an idea of the widget tree, it is as such.
Parent/Container Widget
Form Widget
Button Widget
List Widget
Notice that the form, buttons and list widget are all siblings, inside of the parent/container widget. What I want to happen, is tap on a list item in the list widget, and populate the form widget with the data that gets passed from the list widget.
Here is my parent widget.
import 'package:andplus_flutter_7_gui/model/user.dart';
import 'package:andplus_flutter_7_gui/services/user_service.dart';
import 'package:flutter/material.dart';
import 'package:rxdart/rxdart.dart';
import 'crud_form.dart';
import 'crud_list.dart';
class Crud extends StatefulWidget {
Crud({Key key, this.title}) : super(key: key);
final String title;
_CrudContainerState createState() => _CrudContainerState();
}
class _CrudContainerState extends State<Crud> {
List<User> users;
User user = User();
UserService userService;
#override
void initState() {
super.initState();
if (userService == null) {
userService = UserService(user);
}
}
#override
void dispose() {
// TODO: implement dispose
super.dispose();
userService.dispose();
}
#override
Widget build(BuildContext context) {
return Material(
child: Scaffold(
resizeToAvoidBottomPadding: false,
appBar: AppBar(
title: Text(widget.title),
),
body: Builder(
builder: (context) => Column(
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
flex: 2,
child: StreamBuilder(
builder: (context, AsyncSnapshot<User> snapshot) {
return CrudForm(
user: snapshot.data,
onUserAdded: (user) {
userService.addUser(user);
},
);
},
stream: userService.userObservable,
),
),
Expanded(
child: Text("Future button widget"),
),
Expanded(
flex: 3,
child: StreamBuilder(
builder: (ctx, AsyncSnapshot<List<User>> snap) {
return CrudList(
onUserSelected: userService.userSelected,
users: snap.data,
);
},
stream: userService.usersObservable,
),
),
],
),
),
),
);
}
void onEditUser(User user) {
setState(() {
user = user;
});
}
}
The above widget wraps the three widgets I mentioned.
Here are the children widget:
Form:
import 'package:andplus_flutter_7_gui/model/user.dart';
import 'package:flutter/material.dart';
class CrudForm extends StatefulWidget {
CrudForm({Key key, this.onUserAdded, this.user}) : super(key: key);
final User user;
final void Function(User user) onUserAdded;
_CrudFormState createState() => _CrudFormState(user: user);
}
class _CrudFormState extends State<CrudForm> {
_CrudFormState({this.user});
User user = User();
var _key = GlobalKey<FormState>();
#override
Widget build(BuildContext context) {
return Container(
child: Builder(
builder: (context) => Container(
color: Colors.blueAccent[100],
child: Form(
key: _key,
child: Padding(
padding: const EdgeInsets.only(left: 8.0),
child: Column(
mainAxisSize: MainAxisSize.min,
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Row(
children: <Widget>[
Text(
"First Name",
style: TextStyle(fontSize: 20),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
initialValue: widget.user?.firstName == null ||
widget.user.firstName.isEmpty
? user.firstName
: widget.user.firstName,
validator: (value) {
if (value.isEmpty) {
return "First name is required";
}
return null;
},
onSaved: (value) {
setState(() {
user.firstName = value;
});
},
),
),
)
],
),
Row(
children: <Widget>[
Text(
"Last Name",
style: TextStyle(fontSize: 20),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: TextFormField(
validator: (value) {
if (value.isEmpty) {
return "Last name is required";
}
return null;
},
onSaved: (value) {
setState(() {
user.lastName = value;
});
},
),
),
),
],
),
RaisedButton(
child: Text(
"Save",
),
splashColor: Colors.blueGrey,
onPressed: () {
if (!_key.currentState.validate()) {
return;
}
_key.currentState.save();
widget.onUserAdded(
new User(
firstName: user.firstName,
lastName: user.lastName,
),
);
},
)
],
),
),
),
),
),
);
}
}
Here is my list widget.
import 'package:andplus_flutter_7_gui/model/user.dart';
import 'package:flutter/material.dart';
class CrudList extends StatefulWidget {
CrudList({Key key, this.users, this.onUserSelected}) : super(key: key);
final List<User> users;
final SelectUser onUserSelected;
_CrudListState createState() => _CrudListState();
}
class _CrudListState extends State<CrudList> {
#override
Widget build(BuildContext context) {
return Container(
color: Colors.green,
child: ListView.builder(
itemCount: widget.users?.length ?? 0,
itemBuilder: (BuildContext context, int index) {
var user = widget.users[index];
return ListTile(
key: Key(index.toString()),
title: Center(
child: Text(
"${user.firstName} ${user.lastName}",
style: TextStyle(color: Colors.white),
),
),
onTap: () {
print("${widget.users[index]} $index");
widget.onUserSelected(widget.users[index]);
},
);
},
),
);
}
}
typedef void SelectUser(User user);
And just for further context, here is my user service, responsible for adding the objects to the stream, and using the stream builder within rxdart to notify of state changes.
import 'package:andplus_flutter_7_gui/model/user.dart';
import 'package:rxdart/rxdart.dart';
class UserService {
User _editedUser = User();
List<User> _users = <User>[];
BehaviorSubject<User> _userSubject;
BehaviorSubject<List<User>> _usersSubject;
UserService(this._editedUser) {
_userSubject = BehaviorSubject<User>.seeded(_editedUser);
_usersSubject = BehaviorSubject<List<User>>.seeded(_users);
}
Observable<List<User>> get usersObservable => _usersSubject.stream;
Observable<User> get userObservable => _userSubject.stream;
addUser(User user) {
_users.add(user);
_usersSubject.add(_users);
}
dispose() {
_userSubject.close();
_usersSubject.close();
}
void userSelected(User user) {
_editedUser = user;
_userSubject.add(_editedUser);
}
}
What am I missing? It looks like my widget rebuilds, and tries to set the initial value in the form when I tap the user in the list widget. But the actual field doesn't get updated and I'm not sure why.
I'd appreciate any documentation or articles on how to better approach data and state management between sibling widgets within the flutter framework.
Here's a similar use case that I tried to implement locally. What I'm doing here is I generate TextFormFields dynamically and assign TextEditingController.
Column textField(int n) {
List<Widget> listForm = [];
while (n > 0) {
var textEditingController = TextEditingController();
listForm.add(
TextFormField(
controller: textEditingController,
onTap: () {
_selectedField = textEditingController;
},
),
);
n--;
}
return Column(children: listForm);
}
Clicking a ListView item updates the text of the currently selected TextFormField.
InkWell(
onTap: () {
debugPrint('Selected $index!');
if (_selectedField != null) {
_selectedField!.value = TextEditingValue(text: 'Item $index');
}
},
child: ListTile(
title: Text('Item $index'),
),
);
Complete sample
import 'package:flutter/material.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(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
TextEditingController? _selectedField;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Container(
padding: const EdgeInsets.all(8.0),
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(flex: 1, child: textField(3)),
Expanded(flex: 1, child: listItems()),
],
),
),
),
);
}
Column textField(int n) {
List<Widget> listForm = [];
while (n > 0) {
var textEditingController = TextEditingController();
listForm.add(
TextFormField(
controller: textEditingController,
onTap: () {
debugPrint('Current Controller: $textEditingController');
_selectedField = textEditingController;
},
),
);
n--;
}
return Column(children: listForm);
}
ListView listItems() {
return ListView.builder(
itemCount: 5,
itemBuilder: (BuildContext context, int index) {
return InkWell(
onTap: () {
if (_selectedField != null) {
_selectedField!.value = TextEditingValue(text: 'Item $index');
}
},
child: ListTile(
title: Text('Item $index'),
),
);
},
);
}
}
Demo