So I am implementing a 'settings' view in my Flutter app. The idea is all settings will appear in a ListView, and when the user will click on a ListTile, a showModalBottomSheet will pop where the user will be able to manipulate the setting. The only problem I am having is I am unable to migrate the showModalBottomSheet to a separate class as I cannot make the new function (outside the class) return the manipulated setting variable. This has lead to a messy code, all in a single class.
class Page extends StatefulWidget {
Page({Key key}) : super(key: key);
#override
_Page createState() => _Page();
}
class _Page extends State<Page> {
var value;
#override
Widget build(BuildContext context) {
return ListView(
children: <Widget>[
ListTile(
title: Text("Age"),
trailing: Text(value),
onTap: () {
setState(() {
value = _valueSelector(); // This doesn't work, but to give an idea what I want
});
},
),
],
);
}
}
int _valueSelector(context) { // Doesn't return
var age = 0;
showModalBottomSheet<void>(
context: context,
builder: (BuildContext context) {
return StatefulBuilder(
builder: (BuildContext context, StateSetter setState) {
return Wrap(
children: [
Column(
children: <Widget>[
Slider(
value: age.toDouble(),
min: 0,
max: 18,
divisions: 18,
onChanged: (value) {
setState(() {
age = value.toInt();
});
},
),
],
),
],
);
});
},
).whenComplete(() {
return age; // Not sure if return is supposed to be here
});
}
How can I implement showModalBottomSheet in a separate class and just make it return the variable representing the setting chosen by the user?
You can try the below code,
First, create a class custom_bottom_sheet.dart and add the below code. You can use it everywhere in the project. And also use this library modal_bottom_sheet: ^0.2.0+1 to get the showMaterialModalBottomSheet.
customBottomSheet(BuildContext context, {#required Widget widget}) async {
return await showMaterialModalBottomSheet(
context: context,
backgroundColor: AppColors.transparent_100,
barrierColor: AppColors.black_75,
isDismissible: false,
enableDrag: true,
builder: (_, ScrollController scrollController) {
return widget;
},
);
}
Sample example code:
Create another class called bottom_sheet_example.dart and add the below code.
class BottomSheetExample {
static Future getSheet(BuildContext _context,
{ValueChanged<bool> onChanged}) async {
await customBottomSheet(
_context,
widget: SafeArea(
child: Container(
padding: EdgeInsets.only(left: 40.0, right: 40.0),
height: 170.0,
width: double.infinity,
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(27.0),
topRight: Radius.circular(27.0))),
child: Container(
padding: EdgeInsets.only(top: 32),
child: Column(
children: [
Text("Were you at Queen Victoria Building?"),
SizedBox(height: 48),
Row(
children: [
Expanded(
child: RaisedButton(
child: Text("No"),
onPressed: () {
Navigator.of(_context).pop();
onChanged(false);
},
),
),
SizedBox(width: 18),
Expanded(
child: RaisedButton(
child: Text("Yes"),
onPressed: () {
Navigator.of(_context).pop();
onChanged(true);
},
),
),
],
),
SizedBox(height: 24),
],
),
),
)),
);
}
}
Button click to show the bottom sheet
#override
Widget build(BuildContext context) {
return Scaffold(
body: yourBodyWidget(),
bottomNavigationBar: Container(
height: 40,
width: double.infinity,
child: FlatButton(
onPressed: () {
/// call BottomSheetExample class
BottomSheetExample.getSheet(
context,
onChanged: (bool result) async {
///
/// add your code
},
);
},
child: Text("show bottom sheet")),
),
);
}
In onChanged callback you can return your value(obj/String/num/bool/list).
Thank you!
I am working on a card game and it includes 2 parts.
InputPage
GamePage
In InputPage() user picks cards and it has a new game button. When user click on it, page must be reload. I did this with Navigator.of method. But when user go to GamePage(), i got an error like this:
Unhandled Exception: setState() called after dispose(): _GamePageState#d4518(lifecycle state: defunct, not mounted)
This error happens if you call setState() on a State object for a widget that no longer appears in the widget tree (e.g., whose parent widget no longer includes the widget in its build). This error can occur when code calls setState() from a timer or an animation callback.
The preferred solution is to cancel the timer or stop listening to the animation in the dispose() callback. Another solution is to check the "mounted" property of this object before calling setState() to ensure the object is still in the tree.
This is my code:
ayarAlert2(BuildContext context) async {
AlertDialog alert = AlertDialog(
title: Center(
child: Container(
decoration: BoxDecoration(
borderRadius: const BorderRadius.all(
Radius.circular(15.0),
),
),
child: Text(
" Settings ",
style: TextStyle(color: Colors.white, fontWeight: FontWeight.w300),
),
),
),
backgroundColor: Color(0xFF1F010B),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(15)),
content: Container(
child: Wrap(
runSpacing: 5,
spacing: 10,
children: <Widget>[
FlatButton(
onPressed: () {
Navigator.pop(context);
Navigator.of(context).push(new MaterialPageRoute(
builder: (BuildContext context) => InputPage()));
},
child: Center(
child: Row(
children: [Container(
child: Text(
" New Game ",
style: TextStyle(
color: Colors.white,
fontSize: 32,
fontWeight: FontWeight.w300),
)),
],
),
)),
],
),
),
);
// show the dialog
showDialog(
barrierColor: Colors.black.withOpacity(0.01),
context: context,
builder: (BuildContext context) {
return alert;
},
);
}
When user picks all the cards ,he/she press the " START " button. Heres the start button :
Navigator.of(context).pushReplacement(
new MaterialPageRoute(
builder: (BuildContext context) =>
new GamePage(
mycards: cardBrain.mycards,
yourcards:
cardBrain.rakipcards,
annen: true,
)));
This is InputPage() 's initState
#override
void initState() {
super.initState();
Future.delayed(Duration.zero, () {
showDialog(
context: context,
builder: (context) => AlertDialog(
content: Container(
child: Wrap(
alignment: WrapAlignment.center,
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: [
FlatButton(
onPressed: () {
setState(() {
cardBrain.kartbol();
Navigator.pop(context);
});
},
child: Center(
child: Row(
children: [
Center(
child: Container(
child: Text(
" START ",
)),
),
],
),
)),
],
),
],
),
),
));
});
}
#override
void dispose() {
// TODO: implement dispose
super.dispose();
// animationController.dispose() instead of your controller.dispose
}
And this is GamePage() 's initState :
#override
void initState() {
super.initState();
WidgetsBinding.instance
.addPostFrameCallback((_) => showAlertDialog(context));
_now = DateTime.now().second.toString();
// defines a timer
_everySecond = Timer.periodic(Duration(seconds: 1), (Timer t) {
if (annenn == true) {
setState(() {
_now = DateTime.now().second.toString();
if (cardBrain.bitir == 13) {
if (ihale <= cardBrain.bizimskor) {
mesaj = "WIN";
} else {
mesaj = "LOSE";
}
sonucAlert(context, cardBrain.bizimskor, mesaj, cardBrain.onunskor,
widget.annen);
}
});
}
});
}
A solution would be to use the popAndPushNamed method:
await Navigator.popAndPushNamed(context, '/gameScreen');
Remember to define the route in the MaterialApp class, usually in the main.dart file:
MaterialApp(
initialRoute: '/',
routes: {
'/': (context) => InputPage(),
'/gameScreen': (context) => GamePage(),
},
);
what is the proper way to call Dialog function from another class.
I have been searching this topic for a while but seems none of them are my answer.
my Dialog has a little complicated logic for server communicating and some paginations
so this code is going to be long for just one dart file. so I want to separate them.
and I need the some dialog animations so I picked the showGeneralDialog()
I also saw the example dialog implementaion using StatefulBuilder() which can use setState,
but this problem is it is not able to use initState()
for now, what I did is below
dart1 file
import 'package:aaa/bbb/some_dialog_file.dart'
as someDialog;
GestureDetector(
onTap: () async{
var result =
await someDialog.displayDialogOKCallBack(
context,
);
},
child: Container(
width: 60,
height: 60,
child: Icon(
Icons.comment,
size: 38,
),
),
)
dart2 file
Future<dynamic> displayDialogOKCallBack(BuildContext context) async {
return await showGeneralDialog(
barrierLabel: "Label",
barrierDismissible: true,
// barrierColor: ,
transitionDuration: Duration(milliseconds: 400),
context: context,
pageBuilder: (context, anim1, anim2) {
return StatefulBuilder(builder: (context, setState) {
return Scaffold(
body: SafeArea(
),
);
});
},
transitionBuilder: (context, anim1, anim2, child) {
return SlideTransition(
position:
Tween(begin: Offset(0, 1), end: Offset(0, -0.02)).animate(anim1),
child: child,
);
},
);
}
so my question is I want to build very clean animation dialog
which is logically separated from base class file and it has to have initState(), and setState()
how could I acheive this ? thanks
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Container(
child: RaisedButton(
onPressed: () {
someDialog(context);
},
child: Text("click"),
),
);
}
Future<dynamic> someDialog(BuildContext context) async {
return await showGeneralDialog(
barrierLabel: "Label",
barrierDismissible: true,
context: context,
pageBuilder: (context, anim1, anim2) {
return Scaffold(
backgroundColor: Colors.transparent,
body: SafeArea(
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.end,
children: [
Column(
mainAxisAlignment: MainAxisAlignment.start,
children: [
// List
AnotherClassDialog(),
],
),
],
),
),
),
);
});
}
}
class AnotherClassDialog extends StatefulWidget {
#override
_AnotherClassDialogState createState() => _AnotherClassDialogState();
}
class _AnotherClassDialogState extends State<AnotherClassDialog> {
Color color;
#override
void initState() {
// TODO: implement initState
super.initState();
color = Colors.black;
}
#override
Widget build(BuildContext context) {
return Center(
child: Column(
children: [
RaisedButton(
onPressed: () {
setState(() {
color = Colors.red;
});
},
),
Container(
width: 100,
height: 100,
color: color,
),
RaisedButton(
onPressed: () {
setState(() {
color = Colors.green;
});
},
)
],
),
);
}
}
I use a custom dialog in my app in some classes and had the same problem.
You should define a dialog and pass context and other variables to it and call it everywhere you want.
You can define a dialog like this :
showCustomDialog(BuildContext context, String title, String description) {
showDialog(
context: context,
builder: (BuildContext context) {
return AlertDialog(
title: Text(
title,
textAlign: TextAlign.right,
),
content: SingleChildScrollView(
child: Text(
description,
style: Theme.of(context).textTheme.bodyText1,
textAlign: TextAlign.right,
),
),
actions: [
FlatButton(
child: Text(
'ok',
style: Theme.of(context).textTheme.bodyText2.copyWith(
color: Theme.of(context).accentColor,
),
),
onPressed: () => Navigator.of(context).pop(),
),
],
actionsPadding: EdgeInsets.symmetric(
horizontal: 10,
vertical: 5,
),
);
});
}
and use it everywhere you want like this :
InkWell(
child: Icon(
Icons.error_outline,
size: 17,
),
onTap: () => showCustomDialog(context,"text1" , "text2") ,
),
I hope my answer will help you.
I'm newbie in flutter and wanted to know what is better way to add CircularProgressIndicator in my layout. For example, my login view. This view have username, password and login Button. I did want create a overlay layout (with Opacity) that, when loading, show progress indicator like I use in NativeScript, but I'm little confused with how to do and too if it is the better way. On NativeScript, for example, I add IndicatorActivity in main layout and set busy to true or false, so it overlay all view components when is loading.
Edit:
I was able to reach this result:
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
bool _loading = false;
void _onLoading() {
setState(() {
_loading = true;
new Future.delayed(new Duration(seconds: 3), _login);
});
}
Future _login() async{
setState((){
_loading = false;
});
}
#override
Widget build(BuildContext context) {
var body = new Column(
children: <Widget>[
new Container(
height: 40.0,
padding: const EdgeInsets.all(10.0),
margin: const EdgeInsets.fromLTRB(15.0, 150.0, 15.0, 0.0),
decoration: new BoxDecoration(
color: Colors.white,
),
child: new TextField(
decoration: new InputDecoration.collapsed(hintText: "username"),
),
),
new Container(
height: 40.0,
padding: const EdgeInsets.all(10.0),
margin: const EdgeInsets.all(15.0),
decoration: new BoxDecoration(
color: Colors.white,
),
child: new TextField(
decoration: new InputDecoration.collapsed(hintText: "password"),
),
),
],
);
var bodyProgress = new Container(
child: new Stack(
children: <Widget>[
body,
new Container(
alignment: AlignmentDirectional.center,
decoration: new BoxDecoration(
color: Colors.white70,
),
child: new Container(
decoration: new BoxDecoration(
color: Colors.blue[200],
borderRadius: new BorderRadius.circular(10.0)
),
width: 300.0,
height: 200.0,
alignment: AlignmentDirectional.center,
child: new Column(
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Center(
child: new SizedBox(
height: 50.0,
width: 50.0,
child: new CircularProgressIndicator(
value: null,
strokeWidth: 7.0,
),
),
),
new Container(
margin: const EdgeInsets.only(top: 25.0),
child: new Center(
child: new Text(
"loading.. wait...",
style: new TextStyle(
color: Colors.white
),
),
),
),
],
),
),
),
],
),
);
return new Scaffold(
appBar: new AppBar(
title: new Text(widget.title),
),
body: new Container(
decoration: new BoxDecoration(
color: Colors.blue[200]
),
child: _loading ? bodyProgress : body
),
floatingActionButton: new FloatingActionButton(
onPressed: _onLoading,
tooltip: 'Loading',
child: new Icon(Icons.check),
),
);
}
}
I'm still adapting to the idea of states. This code is within the expected when working with flutter?
In flutter, there are a few ways to deal with Asynchronous actions.
A lazy way to do it can be using a modal. Which will block the user input, thus preventing any unwanted actions.
This would require very little change to your code. Just modifying your _onLoading to something like this :
void _onLoading() {
showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
return Dialog(
child: new Row(
mainAxisSize: MainAxisSize.min,
children: [
new CircularProgressIndicator(),
new Text("Loading"),
],
),
);
},
);
new Future.delayed(new Duration(seconds: 3), () {
Navigator.pop(context); //pop dialog
_login();
});
}
The most ideal way to do it is using FutureBuilder and a stateful widget. Which is what you started.
The trick is that, instead of having a boolean loading = false in your state, you can directly use a Future<MyUser> user
And then pass it as argument to FutureBuilder, which will give you some info such as "hasData" or the instance of MyUser when completed.
This would lead to something like this :
#immutable
class MyUser {
final String name;
MyUser(this.name);
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
Future<MyUser> user;
void _logIn() {
setState(() {
user = new Future.delayed(const Duration(seconds: 3), () {
return new MyUser("Toto");
});
});
}
Widget _buildForm(AsyncSnapshot<MyUser> snapshot) {
var floatBtn = new RaisedButton(
onPressed:
snapshot.connectionState == ConnectionState.none ? _logIn : null,
child: new Icon(Icons.save),
);
var action =
snapshot.connectionState != ConnectionState.none && !snapshot.hasData
? new Stack(
alignment: FractionalOffset.center,
children: <Widget>[
floatBtn,
new CircularProgressIndicator(
backgroundColor: Colors.red,
),
],
)
: floatBtn;
return new ListView(
padding: const EdgeInsets.all(15.0),
children: <Widget>[
new ListTile(
title: new TextField(),
),
new ListTile(
title: new TextField(obscureText: true),
),
new Center(child: action)
],
);
}
#override
Widget build(BuildContext context) {
return new FutureBuilder(
future: user,
builder: (context, AsyncSnapshot<MyUser> snapshot) {
if (snapshot.hasData) {
return new Scaffold(
appBar: new AppBar(
title: new Text("Hello ${snapshot.data.name}"),
),
);
} else {
return new Scaffold(
appBar: new AppBar(
title: new Text("Connection"),
),
body: _buildForm(snapshot),
);
}
},
);
}
}
For me, one neat way to do this is to show a SnackBar at the bottom while the Signing-In process is taken place, this is a an example of what I mean:
Here is how to setup the SnackBar.
Define a global key for your Scaffold
final GlobalKey<ScaffoldState> _scaffoldKey = new GlobalKey<ScaffoldState>();
Add it to your Scaffold key attribute
return new Scaffold(
key: _scaffoldKey,
.......
My SignIn button onPressed callback:
onPressed: () {
_scaffoldKey.currentState.showSnackBar(
new SnackBar(duration: new Duration(seconds: 4), content:
new Row(
children: <Widget>[
new CircularProgressIndicator(),
new Text(" Signing-In...")
],
),
));
_handleSignIn()
.whenComplete(() =>
Navigator.of(context).pushNamed("/Home")
);
}
It really depends on how you want to build your layout, and I am not sure what you have in mind.
Edit
You probably want it this way, I have used a Stack to achieve this result and just show or hide my indicator based on onPressed
class TestSignInView extends StatefulWidget {
#override
_TestSignInViewState createState() => new _TestSignInViewState();
}
class _TestSignInViewState extends State<TestSignInView> {
bool _load = false;
#override
Widget build(BuildContext context) {
Widget loadingIndicator =_load? new Container(
color: Colors.grey[300],
width: 70.0,
height: 70.0,
child: new Padding(padding: const EdgeInsets.all(5.0),child: new Center(child: new CircularProgressIndicator())),
):new Container();
return new Scaffold(
backgroundColor: Colors.white,
body: new Stack(children: <Widget>[new Padding(
padding: const EdgeInsets.symmetric(vertical: 50.0, horizontal: 20.0),
child: new ListView(
children: <Widget>[
new Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center
,children: <Widget>[
new TextField(),
new TextField(),
new FlatButton(color:Colors.blue,child: new Text('Sign In'),
onPressed: () {
setState((){
_load=true;
});
//Navigator.of(context).push(new MaterialPageRoute(builder: (_)=>new HomeTest()));
}
),
],),],
),),
new Align(child: loadingIndicator,alignment: FractionalOffset.center,),
],));
}
}
Create a bool isLoading and set it to false. With the help of ternary operator, When user clicks on login button set state of isLoading to true. You will get circular loading indicator in place of login button
isLoading ? new PrimaryButton(
key: new Key('login'),
text: 'Login',
height: 44.0,
onPressed: setState((){isLoading = true;}))
: Center(
child: CircularProgressIndicator(),
),
You can see Screenshots how it looks while before login is clicked
After login is clicked
In mean time you can run login process and login user. If user credentials are wrong then again you will setState of isLoading to false, such that loading indicator will become invisible and login button visible to user.
By the way, primaryButton used in code is my custom button. You can do same with OnPressed in button.
Step 1: Create Dialog
showAlertDialog(BuildContext context){
AlertDialog alert=AlertDialog(
content: new Row(
children: [
CircularProgressIndicator(),
Container(margin: EdgeInsets.only(left: 5),child:Text("Loading" )),
],),
);
showDialog(barrierDismissible: false,
context:context,
builder:(BuildContext context){
return alert;
},
);
}
Step 2: Call it
showAlertDialog(context);
await firebaseAuth.signInWithEmailAndPassword(email: email, password: password);
Navigator.pop(context);
Example Dialog and login form
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:firebase_auth/firebase_auth.dart';
class DynamicLayout extends StatefulWidget{
#override
State<StatefulWidget> createState() {
// TODO: implement createState
return new MyWidget();
}
}
showAlertDialog(BuildContext context){
AlertDialog alert=AlertDialog(
content: new Row(
children: [
CircularProgressIndicator(),
Container(margin: EdgeInsets.only(left: 5),child:Text("Loading" )),
],),
);
showDialog(barrierDismissible: false,
context:context,
builder:(BuildContext context){
return alert;
},
);
}
class MyWidget extends State<DynamicLayout>{
Color color = Colors.indigoAccent;
String title='app';
GlobalKey<FormState> globalKey=GlobalKey<FormState>();
String email,password;
login() async{
var currentState= globalKey.currentState;
if(currentState.validate()){
currentState.save();
FirebaseAuth firebaseAuth=FirebaseAuth.instance;
try {
showAlertDialog(context);
AuthResult authResult=await firebaseAuth.signInWithEmailAndPassword(
email: email, password: password);
FirebaseUser user=authResult.user;
Navigator.pop(context);
}catch(e){
print(e);
}
}else{
}
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar:AppBar(
title: Text("$title"),
) ,
body: Container(child: Form(
key: globalKey,
child: Container(
padding: EdgeInsets.all(10),
child: Column(children: <Widget>[
TextFormField(decoration: InputDecoration(icon: Icon(Icons.email),labelText: 'Email'),
// ignore: missing_return
validator:(val){
if(val.isEmpty)
return 'Please Enter Your Email';
},
onSaved:(val){
email=val;
},
),
TextFormField(decoration: InputDecoration(icon: Icon(Icons.lock),labelText: 'Password'),
obscureText: true,
// ignore: missing_return
validator:(val){
if(val.isEmpty)
return 'Please Enter Your Password';
},
onSaved:(val){
password=val;
},
),
RaisedButton(color: Colors.lightBlue,textColor: Colors.white,child: Text('Login'),
onPressed:login),
],)
,),)
),
);
}
}
Example from Ui
1. Without plugin
class IndiSampleState extends State<ProgHudPage> {
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Demo'),
),
body: Center(
child: RaisedButton(
color: Colors.blueAccent,
child: Text('Login'),
onPressed: () async {
showDialog(
context: context,
builder: (BuildContext context) {
return Center(child: CircularProgressIndicator(),);
});
await loginAction();
Navigator.pop(context);
},
),
));
}
Future<bool> loginAction() async {
//replace the below line of code with your login request
await new Future.delayed(const Duration(seconds: 2));
return true;
}
}
2. With plugin
check this plugin progress_hud
add the dependency in the pubspec.yaml file
dev_dependencies:
progress_hud:
import the package
import 'package:progress_hud/progress_hud.dart';
Sample code is given below to show and hide the indicator
class ProgHudPage extends StatefulWidget {
#override
_ProgHudPageState createState() => _ProgHudPageState();
}
class _ProgHudPageState extends State<ProgHudPage> {
ProgressHUD _progressHUD;
#override
void initState() {
_progressHUD = new ProgressHUD(
backgroundColor: Colors.black12,
color: Colors.white,
containerColor: Colors.blue,
borderRadius: 5.0,
loading: false,
text: 'Loading...',
);
super.initState();
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('ProgressHUD Demo'),
),
body: new Stack(
children: <Widget>[
_progressHUD,
new Positioned(
child: RaisedButton(
color: Colors.blueAccent,
child: Text('Login'),
onPressed: () async{
_progressHUD.state.show();
await loginAction();
_progressHUD.state.dismiss();
},
),
bottom: 30.0,
right: 10.0)
],
));
}
Future<bool> loginAction()async{
//replace the below line of code with your login request
await new Future.delayed(const Duration(seconds: 2));
return true;
}
}
I took the following approach, which uses a simple modal progress indicator widget that wraps whatever you want to make modal during an async call.
The example in the package also addresses how to handle form validation while making async calls to validate the form (see flutter/issues/9688 for details of this problem). For example, without leaving the form, this async form validation method can be used to validate a new user name against existing names in a database while signing up.
https://pub.dartlang.org/packages/modal_progress_hud
Here is the demo of the example provided with the package (with source code):
Example could be adapted to other modal progress indicator behaviour (like different animations, additional text in modal, etc..).
This is my solution with stack
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'dart:async';
final themeColor = new Color(0xfff5a623);
final primaryColor = new Color(0xff203152);
final greyColor = new Color(0xffaeaeae);
final greyColor2 = new Color(0xffE8E8E8);
class LoadindScreen extends StatefulWidget {
LoadindScreen({Key key, this.title}) : super(key: key);
final String title;
#override
LoginScreenState createState() => new LoginScreenState();
}
class LoginScreenState extends State<LoadindScreen> {
SharedPreferences prefs;
bool isLoading = false;
Future<Null> handleSignIn() async {
setState(() {
isLoading = true;
});
prefs = await SharedPreferences.getInstance();
var isLoadingFuture = Future.delayed(const Duration(seconds: 3), () {
return false;
});
isLoadingFuture.then((response) {
setState(() {
isLoading = response;
});
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(
widget.title,
style: TextStyle(color: primaryColor, fontWeight: FontWeight.bold),
),
centerTitle: true,
),
body: Stack(
children: <Widget>[
Center(
child: FlatButton(
onPressed: handleSignIn,
child: Text(
'SIGN IN WITH GOOGLE',
style: TextStyle(fontSize: 16.0),
),
color: Color(0xffdd4b39),
highlightColor: Color(0xffff7f7f),
splashColor: Colors.transparent,
textColor: Colors.white,
padding: EdgeInsets.fromLTRB(30.0, 15.0, 30.0, 15.0)),
),
// Loading
Positioned(
child: isLoading
? Container(
child: Center(
child: CircularProgressIndicator(
valueColor: AlwaysStoppedAnimation<Color>(themeColor),
),
),
color: Colors.white.withOpacity(0.8),
)
: Container(),
),
],
));
}
}
You can do it for center transparent progress indicator
Future<Null> _submitDialog(BuildContext context) async {
return await showDialog<Null>(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
return SimpleDialog(
elevation: 0.0,
backgroundColor: Colors.transparent,
children: <Widget>[
Center(
child: CircularProgressIndicator(),
)
],
);
});
}
{
isloading? progressIos:Container()
progressIos(int i) {
return Container(
color: i == 1
? AppColors.liteBlack
: i == 2 ? AppColors.darkBlack : i == 3 ? AppColors.pinkBtn : '',
child: Center(child: CupertinoActivityIndicator()));
}
}
You can use FutureBuilder widget instead. This takes an argument which must be a Future. Then you can use a snapshot which is the state at the time being of the async call when loging in, once it ends the state of the async function return will be updated and the future builder will rebuild itself so you can then ask for the new state.
FutureBuilder(
future: myFutureFunction(),
builder: (context, AsyncSnapshot<List<item>> snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
} else {
//Send the user to the next page.
},
);
Here you have an example on how to build a Future
Future<void> myFutureFunction() async{
await callToApi();}
Centered on screen:
Column(
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Row(
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
children: [CircularProgressIndicator()])
])
class Loader extends StatefulWidget {
#override
State createState() => LoaderState();
}
class LoaderState extends State<Loader> with SingleTickerProviderStateMixin {
AnimationController controller;
Animation<double> animation;
#override
void initState() {
super.initState();
controller = AnimationController(
duration: Duration(milliseconds: 1200), vsync: this);
animation = CurvedAnimation(parent: controller, curve: Curves.elasticOut);
animation.addListener(() {
this.setState(() {});
});
animation.addStatusListener((AnimationStatus status) {});
controller.repeat();
}
#override
void dispose() {
controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
color: Colors.blue,
height: 3.0,
width: animation.value * 100.0,
),
Padding(
padding: EdgeInsets.only(bottom: 5.0),
),
Container(
color: Colors.blue[300],
height: 3.0,
width: animation.value * 75.0,
),
Padding(
padding: EdgeInsets.only(bottom: 5.0),
),
Container(
color: Colors.blue,
height: 3.0,
width: animation.value * 50.0,
)
],
);
}
}
Expanded(
child: Padding(
padding:
EdgeInsets.only(left: 20.0, right: 5.0, top:20.0),
child: GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FirstScreen()));
},
child: Container(
alignment: Alignment.center,
height: 45.0,
decoration: BoxDecoration(
color: Color(0xFF1976D2),
borderRadius: BorderRadius.circular(9.0)),
child: Text('Login',
style: TextStyle(
fontSize: 20.0, color: Colors.white))),
),
),
),
For your case, maybe it can be done by using showing a modal with a circle indicator. But I recommend using a simple plugin https://pub.dev/packages/flutter_easyloading.
The installation supper easy. Just run this flutter pub add flutter_easyloading in your terminal
Put this in you main.dart app
import 'package:flutter/material.dart';
import 'package:kunjungi_dokter/pages/welcome.dart';
import 'package:flutter_easyloading/flutter_easyloading.dart'; // <- add this
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: const Welcome(),
builder: EasyLoading.init(), // <- add this
);
}
}
To show the modal or the loading widget, in my case I show it in mya _login function in Login Screen:
import 'package:flutter_easyloading/flutter_easyloading.dart';
// ... other code
_login() async {
EasyLoading.show(status: 'loading...', maskType: EasyLoadingMaskType.black); // code to show modal with masking
var data = await LoginAPI.connectToAPI(
emailController.text, passwordController.text);
if (data.isError) {
EasyLoading.showError('Login Error: ' + data.message); // code to show modal without masking and auto close
} else {
await storage.write(key: 'token', value: data.token);
await storage.write(key: 'email', value: emailController.text);
EasyLoading.showSuccess('Login Success!'); // code to show modal without masking and auto close
Navigator.of(context)
.push(MaterialPageRoute(builder: ((context) => const Home())));
}
}
// ... other code
Tips, you can use this to close the modal:
EasyLoading.dismiss();
You will need a library for it
void onLoading() {
showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) {
return GFLoader(
type: GFLoaderType.android,
);
},
);
}
and then use this function where you need in code
onLoading;