am creating checkbox like this:
for (var a in user.poll.questions[i].options) {
children.add(
new Row(
children: [
new Checkbox(
value: checkBoxValue,
onChanged: (bool newValue) {
setState(() {
checkBoxValue = newValue;
});
}
),
new Text(a.text),
],
),
);
}
and this will create this:
Which is what i need .. but the problem is when one checked all will be updated and be checked and reverse ...
i want to check one .. and only this one will be checked and i get its value ..
how to do this? is there is checkbox id or something?
You can save selected question - something like:
Question selectedQuestion = null;
.....
for (var a in user.poll.questions[i].options) {
children.add(
new Row(
children: [
new Checkbox(
value: selectedQuestion == a,
onChanged: (bool newValue) {
setState(() {
selectedQuestion = a;
});
}
),
new Text(a.text),
],
),
);
}
UPD
For multiple checking:
1 - set list instead of one value
final List<Question> questionList = [];
2 - change CheckBox behavior
Checkbox(
value: questionList.contains(a),
onChanged: (bool newValue) {
setState(() {
newValue ? questionList.add(a) : questionList.remove(a);
});
}
)
Related
If you make a new Flutter project and include the dependencies and then replace your main.dart file you should be where I am on this question.
I left the original load: with Future.delayed but it doesn't seem to matter. I know partially what my problem is but am unable to come up with a better solution.
1) I don't seem to be using my snapshot.data and instead I am just making a empty List with str and then i just addAll into it and use that. So i'd love to not do that, i originally was using snapshot.data but ran into problems when I tried to "pull to load more data" which happens after you scroll to the bottom of the list.
The problem with my current method of doing this is that if you pull to load more users and then try to pull again before the users have loaded, The app breaks and doesn't wait for the data to properly load. I believe that I need to be doing that all in the load: of this library easy_refresh... but I am not sure how to rewrite my code to accomplish that.
How can I get my data to load with snapshot.data and then when I pull to refresh, I append 100 more users to that list but the UI waits for the list to update before it finishes the load. Would I be better off just putting a Blocking UI element and after the str list updates? and when new users are loaded I unblock the UI? which sorta feels hackish and not the correct way to solve this. The plugin itself should be able to do the loading and when its ready it stops the spinner under the list and says "finished".
pubspec.yaml
dependencies:
flutter:
sdk: flutter
flutter_easyrefresh: ^1.2.7
http: ^0.12.0+2
main.dart
import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:convert';
import 'package:flutter_easyrefresh/easy_refresh.dart';
import 'package:http/http.dart' as http;
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
backgroundColor: Colors.white
),
home: DuelLeaderBoards(),
);
}
}
class DuelLeaderBoards extends StatefulWidget {
#override
_DuelLeaderBoardsState createState() => _DuelLeaderBoardsState();
}
class _DuelLeaderBoardsState extends State<DuelLeaderBoards> {
List<Entry> str = [];
GlobalKey<EasyRefreshState> _easyRefreshKey = new GlobalKey<EasyRefreshState>();
GlobalKey<RefreshHeaderState> _headerKey = new GlobalKey<RefreshHeaderState>();
GlobalKey<RefreshHeaderState> _connectorHeaderKey = new GlobalKey<RefreshHeaderState>();
GlobalKey<RefreshFooterState> _footerKey = new GlobalKey<RefreshFooterState>();
GlobalKey<RefreshFooterState> _connectorFooterKey = new GlobalKey<RefreshFooterState>();
Future<LeaderBoards> getLeaderBoards(start) async {
String apiURL = 'https://stats.quake.com/api/v2/Leaderboard?from=$start&board=duel&season=current';
final response = await http.get(apiURL);
if (response.statusCode == 200) {
final responseBody = leaderBoardsFromJson(response.body);
return responseBody;
} else {
throw Exception('Failed to load Data');
}
}
void updateLeaderBoardList(e) async {
setState(() {
str.addAll(e.entries);
});
}
#override
void initState() {
getLeaderBoards(0).then((onValue) => str = onValue.entries );
super.initState();
}
#override
Widget build(BuildContext context) {
Widget header = ClassicsHeader(
key: _headerKey,
refreshText: "pullToRefresh",
refreshReadyText: "releaseToRefresh",
refreshingText: "refreshing...",
refreshedText: "refreshed",
moreInfo: "updateAt",
bgColor: Colors.transparent,
textColor: Colors.white,
);
Widget footer = ClassicsFooter(
key: _footerKey,
loadHeight: 50.0,
loadText: "pushToLoad",
loadReadyText: "releaseToLoad",
loadingText: "loading",
loadedText: "loaded",
noMoreText: "Finished",
moreInfo: "updateAt",
bgColor: Colors.transparent,
textColor: Colors.white,
);
return FutureBuilder(
future: getLeaderBoards(0),
builder:
(BuildContext context, AsyncSnapshot<LeaderBoards> snapshot) {
if (!snapshot.hasData) {
return Center(
child: CircularProgressIndicator(),
);
} else {
return Builder(builder: (BuildContext context) {
return Center(
child: new EasyRefresh(
key: _easyRefreshKey,
behavior: ScrollOverBehavior(),
refreshHeader: ConnectorHeader(
key: _connectorHeaderKey,
header: header,
),
refreshFooter: ConnectorFooter(
key: _connectorFooterKey,
footer: footer,
),
child: CustomScrollView(
semanticChildCount: str.length,
slivers: <Widget>[
SliverList(
delegate: SliverChildListDelegate(<Widget>[header]),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(context, index) {
return new Container(
height: 70.0,
child: Card(
child: new Text(
'${index+1}: ${str[index].userName}',
style: new TextStyle(fontSize: 18.0),
),
));
},
childCount: str.length,
)),
SliverList(
delegate: SliverChildListDelegate(<Widget>[footer]),
)
],
),
onRefresh: () async {
await new Future.delayed(const Duration(seconds: 0), () {
setState(() {});
});
},
loadMore: () async {
getLeaderBoards(str.length).then((onValue) => {
updateLeaderBoardList(onValue)
});
},
// loadMore: () async {
// await new Future.delayed(const Duration(seconds: 0), () {
// getLeaderBoards(str.length).then((onValue) => {
// updateLeaderBoardList(onValue)
// });
// });
// },
)
);
});
}
});
}
}
LeaderBoards leaderBoardsFromJson(String str) {
final jsonData = json.decode(str);
return LeaderBoards.fromJson(jsonData);
}
String leaderBoardsToJson(LeaderBoards data) {
final dyn = data.toJson();
return json.encode(dyn);
}
class LeaderBoards {
String boardType;
List<Entry> entries;
int totalEntries;
LeaderBoards({
this.boardType,
this.entries,
this.totalEntries,
});
factory LeaderBoards.fromJson(Map<String, dynamic> json) => new LeaderBoards(
boardType: json["boardType"] == null ? null : json["boardType"],
entries: json["entries"] == null ? null : new List<Entry>.from(json["entries"].map((x) => Entry.fromJson(x))),
totalEntries: json["totalEntries"] == null ? null : json["totalEntries"],
);
Map<String, dynamic> toJson() => {
"boardType": boardType == null ? null : boardType,
"entries": entries == null ? null : new List<dynamic>.from(entries.map((x) => x.toJson())),
"totalEntries": totalEntries == null ? null : totalEntries,
};
}
class Entry {
String userName;
int eloRating;
String profileIconId;
String namePlateId;
Entry({
this.userName,
this.eloRating,
this.profileIconId,
this.namePlateId,
});
factory Entry.fromJson(Map<String, dynamic> json) => new Entry(
userName: json["userName"] == null ? null : json["userName"],
eloRating: json["eloRating"] == null ? null : json["eloRating"],
profileIconId: json["profileIconId"] == null ? null : json["profileIconId"],
namePlateId: json["namePlateId"] == null ? null : json["namePlateId"],
);
Map<String, dynamic> toJson() => {
"userName": userName == null ? null : userName,
"eloRating": eloRating == null ? null : eloRating,
"profileIconId": profileIconId == null ? null : profileIconId,
"namePlateId": namePlateId == null ? null : namePlateId,
};
}
I looked at the documentation of loadMore. Since it says that the body of the function assigned to loadMore should be async, you do not need to use then:
loadMore: () async {
final result = await getLeaderBoards(str.length);
updateLeaderboardList(result);
},
loadMore: () async {
await getLeaderBoards(str.length).then((onValue) => {
updateLeaderboardList(onValue)
});
},
but putting "await" my loader waits for the function to complete before it finishes the animation.
I'm trying to implement same layout in flutter how can i achieve it, i have already tried using wrap widget but Textfield getting full width and changing textfield width dynamically based on content is not possible
I don't know if this is too late. But this library is exactly what you need. You have all steps on the website.
It's a library called Flutter Chips. There are the steps and I'll put the link from the library too.
https://pub.dev/packages/flutter_chips_input
First of all install the library:
dependencies:
flutter_chips_input: ^1.9.4
Here is the code part:
ChipsInput(
initialValue: [
AppProfile('John Doe', 'jdoe#flutter.io', 'https://d2gg9evh47fn9z.cloudfront.net/800px_COLOURBOX4057996.jpg')
],
decoration: InputDecoration(
labelText: "Select People",
),
maxChips: 3,
findSuggestions: (String query) {
if (query.length != 0) {
var lowercaseQuery = query.toLowerCase();
return mockResults.where((profile) {
return profile.name.toLowerCase().contains(query.toLowerCase()) || profile.email.toLowerCase().contains(query.toLowerCase());
}).toList(growable: false)
..sort((a, b) => a.name
.toLowerCase()
.indexOf(lowercaseQuery)
.compareTo(b.name.toLowerCase().indexOf(lowercaseQuery)));
} else {
return const <AppProfile>[];
}
},
onChanged: (data) {
print(data);
},
chipBuilder: (context, state, profile) {
return InputChip(
key: ObjectKey(profile),
label: Text(profile.name),
avatar: CircleAvatar(
backgroundImage: NetworkImage(profile.imageUrl),
),
onDeleted: () => state.deleteChip(profile),
materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
);
},
suggestionBuilder: (context, state, profile) {
return ListTile(
key: ObjectKey(profile),
leading: CircleAvatar(
backgroundImage: NetworkImage(profile.imageUrl),
),
title: Text(profile.name),
subtitle: Text(profile.email),
onTap: () => state.selectSuggestion(profile),
);
},
)
I need to change application locale programmatically when button pressed
my code :
MaterialApp(
localizationsDelegates: [
_newLocaleDelegate,
const AppTranslationsDelegate(),
GlobalMaterialLocalizations.delegate,
GlobalWidgetsLocalizations.delegate,
],
supportedLocales: [
const Locale('en', ''),
const Locale('ar', ''),
],
locale: mylocale,
title: appTitle,
home: Scaffold(
body: new MyCustomForm(),
),
debugShowCheckedModeBanner: false
);
new MaterialButton(
onPressed: () {
setState(() {
mylocale=Locale("ar","");
_newLocaleDelegate = AppTranslationsDelegate(newLocale:mylocale);
});
},
),
translation code :
AppTranslations.of(context).text("text")
AppTranslations Class:
class AppTranslations {
Locale locale;
static Map<dynamic, dynamic> _localisedValues;
AppTranslations(Locale locale) {
this.locale = locale;
_localisedValues = null;
}
static AppTranslations of(BuildContext context) {
return Localizations.of<AppTranslations>(context, AppTranslations);
}
static Future<AppTranslations> load(Locale locale) async {
AppTranslations appTranslations = AppTranslations(locale);
String jsonContent =
await rootBundle.loadString("assets/locale/localization_${locale.languageCode}.json");
_localisedValues = json.decode(jsonContent);
return appTranslations;
}
get currentLanguage => locale.languageCode;
String text(String key) {
print(key);
if(_localisedValues!=null)
return _localisedValues[key] ?? "$key";
else
return key;
}
}
my problem :
when Locale change page direction changed without translation ,
to get effect translation need to refresh page or go to another page and return back,
any help
Could you try wrapping your MaterialApp in an AnimatedSwitcher like so:
AnimatedSwitcher(
// Following two fields for your reference
// duration: const Duration(milliseconds: 500),
// transitionBuilder: (Widget child, Animation<double> animation) {
// return ScaleTransition(child: child, scale: animation);
// },
child: MaterialApp(
// As before, the same code, however:
key: ValueKey<Locale>(mylocale),
)
)
BTW, good practice to prefix private variables with an underscore, e.g. _myLocale.
I'm familiar with form validation using a TextFormField in Flutter, but is it possible to integrate a DropdownButton into a Form and require one of its value be selected before submission?
Basically, integrate DropdownButton validation into this basic Flutter validation example:
https://flutter.io/cookbook/forms/validation/
Dart Package have already the widget DropdownButtonFormField for this. Here is an example of how to use it:
List<String> typeNeg = [
"One",
"Two",
"Three",];
String dropdownValue = "One";
DropdownButtonFormField<String>(
value: dropdownValue,
hint: Text("Type of business"),
onChanged: (String newValue) {
setState(() {
dropdownValue = newValue;
});
},
validator: (String value) {
if (value?.isEmpty ?? true) {
return 'Please enter a valid type of business';
}
},
items: typeNeg
.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(value),
);
}).toList(),
onSaved: (val) => setState(() => _user.typeNeg = val),
),
The user model is as follows:
class User {
int id;
String name;
String email;
String typeNeg;
User({this.id, this.name, this.email, this.typeNeg});
factory User.fromJson(Map<String, dynamic> parsedJson) {
return User(
id: parsedJson["id"],
name: parsedJson["name"] as String,
email: parsedJson["email"] as String,
typeNeg: parsedJson["typeNeg"] as String,
);
}
save(){
print("User saved");
}
}
To try the validator option change String dropdownValue = "One"; to String dropdownValue = null;
From text_form_field.dart file in Flutter's source code you can see that TextFormField is no more than a FormField emitting a TextField widget in its builder callback. You can write your own DropdownFormField using a similar pattern. Here's mine:
import 'package:flutter/material.dart';
class DropdownFormField<T> extends FormField<T> {
DropdownFormField({
Key key,
InputDecoration decoration,
T initialValue,
List<DropdownMenuItem<T>> items,
bool autovalidate = false,
FormFieldSetter<T> onSaved,
FormFieldValidator<T> validator,
}) : super(
key: key,
onSaved: onSaved,
validator: validator,
autovalidate: autovalidate,
initialValue: items.contains(initialValue) ? initialValue : null,
builder: (FormFieldState<T> field) {
final InputDecoration effectiveDecoration = (decoration ?? const InputDecoration())
.applyDefaults(Theme.of(field.context).inputDecorationTheme);
return InputDecorator(
decoration:
effectiveDecoration.copyWith(errorText: field.hasError ? field.errorText : null),
isEmpty: field.value == '' || field.value == null,
child: DropdownButtonHideUnderline(
child: DropdownButton<T>(
value: field.value,
isDense: true,
onChanged: field.didChange,
items: items.toList(),
),
),
);
},
);
}
The key is to bind DropdownButton's onChanged to field.didChange. Usage is pretty straightforward:
DropdownFormField<String>(
validator: (value) {
if (value == null) {
return 'Required';
}
},
onSaved: (value) {
// ...
},
decoration: InputDecoration(
border: UnderlineInputBorder(),
filled: true,
labelText: 'Demo',
),
initialValue: null,
items: [
DropdownMenuItem<String>(
value: '1',
child: Text('1'),
),
DropdownMenuItem<String>(
value: '2',
child: Text('2'),
)
],
),
I got the idea from this site. The difference is that my version of DropdownFormField is closer to Flutter's native implementation (which extends TextFormField instead of wrapping it inside a StatefulWidget).
I have a code like this below, the simple flow is I make a loop from a list of objects to create some widgets.
class ScoringAttribute {
int _id;
bool _isdelete;
double _scorehigh, _scorelow, _scorevalue;
String _name, _scoretype, _description, _title;
}
class HomePageState extends State<HomePage> with TickerProviderStateMixin {
List dataScoringAttributes;
List<ScoringAttribute> listScoringAttributeObjects = new List<ScoringAttribute>();
final String urlPresentation = ".../.resentations/getPresentations";
final String urlScoringAttribute = ".../.scoringattributes/getScoringattributes";
Future<String> getPresentationData() async {
var responseScoringAttribute = await http.get(
Uri.encodeFull(urlScoringAttribute),
headers: {"Accept": "application/json"}
);
var scoringAttributeJson = json.decode(responseScoringAttribute.body);
dataScoringAttributes = scoringAttributeJson['scoringattributes'];
for(int i = 0; i < dataScoringAttributes.length; i++) {
var scoringAttributeObject = new ScoringAttribute();
scoringAttributeObject._id = dataScoringAttributes[i]["id"];
scoringAttributeObject._description = dataScoringAttributes[i]["iddescription"];
scoringAttributeObject._isdelete = dataScoringAttributes[i]["isdelete"];
scoringAttributeObject._name = dataScoringAttributes[i]["name"];
scoringAttributeObject._scorehigh = double.parse(dataScoringAttributes[i]["scorehigh"].toString());
scoringAttributeObject._scorelow = double.parse(dataScoringAttributes[i]["scorelow"].toString());
scoringAttributeObject._scoretype = dataScoringAttributes[i]["scoretype"];
scoringAttributeObject._title = dataScoringAttributes[i]["title"];
scoringAttributeObject._scorevalue = double.parse(dataScoringAttributes[i]["scorelow"].toString());
listScoringAttributeObjects.add(scoringAttributeObject);
}
return "Success";
}
List<Widget> scoringAttributeList() {
List<Widget> list = new List();
for(int i = 0; i < listScoringAttributeObjects.length; i++) {
if(listScoringAttributeObjects[i]._scoretype == "slider") {
list.add(
new Container(
child: new Column(
children: <Widget>[
new Column(
children: <Widget>[
//THE SLIDER VALUE TEXT
new Text(
//CONVERT DOUBLE TYPE TO STRING WITHOUT DECIMAL POINTS
listScoringAttributeObjects[i]._scorevalue.toStringAsFixed(listScoringAttributeObjects[i]._scorevalue.truncateToDouble() == listScoringAttributeObjects[i]._scorevalue ? 0 : 0),
style: new TextStyle(
fontSize: 28.0,
),
),
//THE SLIDER
new Slider(
activeColor: Colors.blueAccent,
inactiveColor: const Color(0xFFb7d2e0),
min: double.parse(listScoringAttributeObjects[i]._scorelow.toString()),
max: double.parse(listScoringAttributeObjects[i]._scorehigh.toString()),
value: double.parse(listScoringAttributeObjects[i]._scorevalue.toString()),
onChanged: (double value) {
setState(() {
listScoringAttributeObjects[i]._scorevalue = double.parse(value.round().toString());
});
},
),
],
),
],
),
),
);
}
else if(listScoringAttributeObjects[i]._scoretype == "text_field") {
list.add(...);
}
else if(listScoringAttributeObjects[i]._scoretype == "stars") {
list.add(...);
}
else if(listScoringAttributeObjects[i]._scoretype == "thumb") {
list.add(new Container(...);
}
}
return list;
}
#override
Widget build(BuildContext context) {
return new Scaffold(
body: FutureBuilder<String> (
future: getPresentationData(),
builder: (context, snapshot) {
if(snapshot.hasData) {
return new Column(
children: <Widget>[
new Column(
children: scoringAttributeList(),
),
],
),
}
},
),
);
}
}
There are some different widgets depending on the type, and there are 4 types, and 1 type might have more than 1 widget in it, so I make the loop depend on the data that it got from DB.
The problem is I don't know why every time I use setState() inside the loop, it always processes the loop again, so it'll be an infinite loop to create a new widget, and it'll duplicate the widget from the beginning (only happen when the setState() is called).
Ex: there are 4 data inside the List, and if the setState() is called, it'll show 8 data (show the first 4 data twice)
Here's the example of how I setState() into the data inside the List
onChanged: (double value) {
setState(() {
listScoringAttributeObjects[i]._scorevalue = double.parse(value.round().toString());
});
},
I think the problem is because I setState() into some data inside the List. So when the List state is changed, it'll re-render anything that is related to the List.
Is it true?
If yes, is there any other solution how to change my code?
If not, is there any mistake in my code or my logic maybe?
Thank you. Really looking forward to some solution about this, cause I really got stuck in this, and its already been a week :(
Simple move your getPresentationData() into state variable. So that it will get triggered only once.
class HomePageState extends State<HomePage> with TickerProviderStateMixin {
Future<String> _presentationFuture;
initState() {
_presentationFuture = getPresentationData()
}
//other contents
#override
Widget build(BuildContext context) {
return new Scaffold(
body: FutureBuilder<String> (
future: _presentationFuture,
builder: (context, snapshot) {
if(snapshot.hasData) {
Reason for duplicate: we can calling setState on Slider dataChange which will re-render the HomePageState which will again trigger the network call (getPresentationData())
Note: If you want to trigger network on slider change, clear the list before making a network call
Future<String> getPresentationData() async {
listScoringAttributeObjects = new List<ScoringAttribute>(); // clear data
var responseScoringAttribute = await http.get(
Uri.encodeFull(urlScoringAttribute),
headers: {"Accept": "application/json"}
);
I don't see how this would be related to the one setState() in your code. It is only called when the slider is used.
I think the problem is caused by list.add(...); in scoringAttributeList(). You shouldn't modify data when build() is executed.
You should assume that build() can be called repeatedly and at any time.
Build your code so that this doesn't cause issues when it happens.