How to center the Title of a ListTile in Flutter - flutter

I have been trying again today to center the title of a Flutter ListTile. Over the past few days I have spent an hour or two Googling and trying things then loosing my cool and giving up.
I am just learning Flutter and love the concept but can find no video training courses (Lynda.com, uDemy.com etc). I have read through the relevant documentation but cannot get rid of all the red lines that appear when I try to apply them to my code.
There must be logic in the syntax but after 2 weeks I have not worked it out yet.
Back to the problem, I have tried
List<Widget> list = <Widget>[
new ListTile(
new child: Center (
title:
new Text('Title 1',
style: new TextStyle(
fontWeight: FontWeight.w500,
color: Colors.deepOrangeAccent,
fontSize: 25.0)),
)
),
];
List<Widget> list = <Widget>[
new ListTile(
title:
new child: Center (
new Text('Title 2',
style: new TextStyle(
fontWeight: FontWeight.w500,
color: Colors.deepOrangeAccent,
fontSize: 25.0)),
)
),
];
List<Widget> list = <Widget>[
new ListTile(
child: Center
title: (
new Text('Title 3',
style: new TextStyle(
fontWeight: FontWeight.w500,
color: Colors.deepOrangeAccent,
fontSize: 25.0)),
)
),
];
List<Widget> list = <Widget>[
new ListTile(
title: Center
new Text('Title 4',
style: new TextStyle(
fontWeight: FontWeight.w500,
color: Colors.deepOrangeAccent,
fontSize: 25.0)),
)
),
];
Please help me with this problem and also where to find a video course on Flutter?
On the upside, if this continues I will no longer be grey, I will be bald instead.
I thought I worked it out when I added 'textAlign: TextAlign.center,' to the text object. There were no red lines but the text was still left aligned.

I am not sure what have you tried, but you in order to center the title of the ListTile you can use a center widget like you did in your code, or wrap your text within a Row widget and set mainAxisAlignment: MainAxisAlignment.center.
Using Center widget:
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text("ListTile Example"),),
body: new ListView(
children: new List.generate(7, (int index) {
return new ListTile(
title: new Center(child: new Text("Centered Title#$index",
style: new TextStyle(
fontWeight: FontWeight.w500, fontSize: 25.0),)),
subtitle: new Text("My title is centered"),
);
}),
),
);
}
Using Row widget:
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text("ListTile Example"),),
body: new ListView(
children: new List.generate(7, (int index) {
return new ListTile(
title: new Row(children: <Widget>[new Text("Centered Title#$index",
style: new TextStyle(
fontWeight: FontWeight.w500, fontSize: 25.0),)
], mainAxisAlignment: MainAxisAlignment.center,),
subtitle: new Text("My title is centered"),
);
}),
),
);
}
However, your problem is not about centering the title, it is about you are trying to insert too big of a Text inside a small area, that is why you are getting the red lines, so one solution is choose a smaller fontSize, a better solution is to get rid of ListTile and build your own custom widget, since a ListTile is
A single fixed-height row that typically contains some text as well as
a leading or trailing icon.
So it should not be used if you are using bigger widgets.
This is simple example of how to create a custom widget that resembles ListTile, but is more flexible and customizable when dealing with larger items:
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(title: new Text("ListTile Example"),),
body: new ListView(
children: new List.generate(7, (int index) {
return new Container(
padding: const EdgeInsets.symmetric(
vertical: 10.0, horizontal: 20.0),
child: new Column(
children: <Widget>[
new Align (child: new Text("Centered Title $index",
style: new TextStyle(fontSize: 40.0),), //so big text
alignment: FractionalOffset.topLeft,),
new Divider(color: Colors.blue,),
new Align (child: new Text("Subtitle $index"),
alignment: FractionalOffset.topLeft,),
new Divider(color: Colors.blue,),
new Align (child: new Text("More stuff $index"),
alignment: FractionalOffset.topLeft,),
new Row(mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[ //add some actions, icons...etc
new FlatButton(onPressed: () {}, child: new Text("EDIT")),
new FlatButton(onPressed: () {},
child: new Text("DELETE",
style: new TextStyle(color: Colors.redAccent),))
],),
],
),
);
}),
)
);
}

You can change the alignment of the text by using textAlign
Use this to center the Title of a ListTile:
ListTile(title: Text('YOUR TEXT', textAlign: TextAlign.center));

Here is my example of a three-row tile:
class ThreeRowTile extends StatelessWidget {
final Widget title;
final Widget detail;
final String utility1;
final String utility1Help;
final String utility2Help;
final String utility2;
final Icon icon;
final String cell;
final String home;
final String office;
final String email;
final VoidCallback cellTapped;
final VoidCallback cellLongPressed;
final VoidCallback iconTapped;
ThreeRowTile({
this.title,
this.icon,
this.detail,
this.utility1,
this.utility1Help,
this.utility2,
this.utility2Help,
this.cellTapped,
this.home,
this.email,
this.cell,
this.office,
this.cellLongPressed,
this.iconTapped,
});
#override
Widget build(BuildContext context) {
List<Widget> buildChildren() {
List<Widget> builder = [];
if (cell.isNotEmpty && !cell.toString().contains("--")) {
builder.add(ListTile(
leading: const Icon(Icons.phone),
title: Text(
'Cell',
textScaleFactor: globals.textScaleFactor,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle: Text(
cell.toString().length > 0 ? cell : "No Number Found",
textScaleFactor: globals.textScaleFactor,
),
onTap: cell.toString().contains("--")
? null
: () {
globals.Utility.makePhoneCall(context, cell);
},
));
}
if (office.isNotEmpty && !office.toString().contains("--")) {
builder.add(ListTile(
leading: const Icon(Icons.work),
title: Text(
'Office',
textScaleFactor: globals.textScaleFactor,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle: Text(
office.toString().length > 0 ? office : "No Number Found",
textScaleFactor: globals.textScaleFactor,
),
onTap: office.toString().contains("--")
? null
: () {
globals.Utility.makePhoneCall(context, office);
},
));
}
if (home.isNotEmpty && !home.toString().contains("--")) {
builder.add(ListTile(
leading: const Icon(Icons.home),
title: Text(
'Home',
textScaleFactor: globals.textScaleFactor,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle: Text(
home.toString().length > 0 ? home : "No Number Found",
textScaleFactor: globals.textScaleFactor,
),
onTap: home.toString().contains("--")
? null
: () {
globals.Utility.makePhoneCall(context, home);
},
));
}
if (email.isNotEmpty && !email.contains('No Email Address')) {
builder.add(ListTile(
leading: const Icon(Icons.email),
title: Text(
'Email',
textScaleFactor: globals.textScaleFactor,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
subtitle: Text(
email.toString().length > 0 ? email : "No Email Found",
textScaleFactor: globals.textScaleFactor,
),
onTap: email.toString().isEmpty
? null
: () {
globals.Utility.sendEmail(context, email);
},
));
}
if (builder.isEmpty) {
builder.add(
ListTile(
leading: const Icon(Icons.info),
title: Text(
'No Contact Information Found',
textScaleFactor: globals.textScaleFactor,
style: TextStyle(
fontWeight: FontWeight.bold,
),
),
),
);
}
return builder;
}
String _utility1 =
utility1 == null || utility1.contains("1-1-1800") ? "" : utility1;
String _utility2 =
utility2 == null || utility2.contains("1-1-1800") ? "" : utility2;
var rowCard = Container(
decoration: BoxDecoration(
border: Border(bottom: BorderSide(color: Colors.grey[300]))),
child: Container(
padding: const EdgeInsets.symmetric(vertical: 10.0, horizontal: 5.0),
child: new Column(
children: <Widget>[
Row(
children: <Widget>[
Align(
child: IconButton(
icon: icon,
onPressed: iconTapped,
),
alignment: FractionalOffset.centerLeft,
),
Expanded(
child: Column(
children: <Widget>[
new Align(
child: title, //so big text
alignment: FractionalOffset.topLeft,
),
// new Divider(),
new Align(
child: detail,
alignment: FractionalOffset.topLeft,
),
// new Divider(),
Row(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Expanded(
child: Container(
margin: const EdgeInsets.all(3.0),
padding: const EdgeInsets.all(3.0),
decoration: BoxDecoration(
border: Border.all(
color: _utility1.length > 1
? Colors.grey
: Colors.transparent)),
child: Tooltip(
message:
utility1Help == null ? "" : utility1Help,
child: Text(
_utility1,
maxLines: 1,
textAlign: TextAlign.center,
textScaleFactor: globals.textScaleFactor,
),
),
),
),
Expanded(
child: Container(
margin: const EdgeInsets.all(3.0),
padding: const EdgeInsets.all(3.0),
decoration: BoxDecoration(
border: Border.all(
color: _utility2.length > 1
? Colors.grey
: Colors.transparent)),
child: Tooltip(
message: utility2 == null ? "" : utility2,
child: Text(
_utility2,
maxLines: 1,
textAlign: TextAlign.center,
textScaleFactor: globals.textScaleFactor,
),
),
),
),
],
),
],
),
),
Align(
child: IconButton(
icon: Icon(Icons.arrow_drop_down),
onPressed: () {
showModalBottomSheet<void>(
context: context,
builder: (BuildContext context) {
return Container(
child: Padding(
padding: EdgeInsets.only(bottom: 10.0),
child: SingleChildScrollView(
child: Column(
mainAxisSize: MainAxisSize.min,
children: buildChildren()),
),
));
});
},
),
alignment: FractionalOffset.centerRight,
),
],
),
],
),
),
// color: globals.isDarkTheme ? Colors.black45 : Colors.white,
);
return (rowCard);
}
}
And it can be used like this:
ThreeRowTile(
icon: Icon(Icons.person),
title: _contacts?.items[index]?.lastName.toString().isEmpty &&
_contacts?.items[index]?.firstName.toString().isEmpty
? null
: Text(
(_contacts?.items[index]?.lastName ?? "") +
", " +
(_contacts?.items[index]?.firstName ?? ""),
textScaleFactor: globals.textScaleFactor,
),
detail: Text(
_contacts?.items[index]?.lastActivity,
textScaleFactor: globals.textScaleFactor,
),
utility1: _contacts?.items[index]?.dateCreated,
utility1Help: 'Date Created',
utility2: _contacts?.items[index]?.dateModified,
utility2Help: "Date Modified",
cell: _contacts?.items[index]?.cell,
home: _contacts?.items[index]?.home,
office: _contacts?.items[index]?.office,
email: _contacts?.items[index]?.email,
cellTapped: () {
globals.contactID = _contacts?.items[index]?.contactID;
Navigator.of(context).pushNamed("/contact_details").then((value) {
if (globals.infoChanged) {
_getData("", false).then((newitems) {
setState(() {
_contacts = newitems;
});
});
}
});
},
);

Related

how to remove a value from a list using remove() and setState() in Stateful widget in flutter using onpressed property of a button?

I'm trying to delete a quote from the list on clicking the button. but on click the list doesn't seem to be updated or the quote isn't being deleted on click.
any solutions would be appreciated !!!
this is a list of quotes which i'm displaying in a card in the activity
List<Quote> quotes =[
Quote(quote: "be yourself; everyone else is already taken",author: "oscar wilde"),
Quote(quote: "this is test quote 2",author: "mikey"),
Quote(quote: "good thing about music, when it hits you, you feel no pain",author: "bob marley"),
];
using a textbutton to delete a particular quote on click
class QuoteCard extends StatelessWidget {
final Quote quote;
final Function delete;
QuoteCard({required this.quote, required this.delete});
#override
Widget build(BuildContext context) {
return Card(
margin: EdgeInsets.fromLTRB(16, 16, 16, 0),
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
quote.quote,
style: TextStyle(
fontSize: 18,
color: Colors.grey[600],
),
),
SizedBox(height: 10,),
Text(
quote.author,
style: TextStyle(
fontSize: 14,
color: Colors.grey[800],
),
),
SizedBox(height: 8.0,),
TextButton(
onPressed: (){ delete; },
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(Icons.delete),
Text(
'delete quote',
),
],
)
)
],
),
),
);
}
}
trying to delete the quote using the remove() method in setState()
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.grey[200],
appBar: AppBar(
title: Text('Awesome Quotes'),
centerTitle: true,
backgroundColor: Colors.redAccent,
),
body: Column(
children: quotes.map((quote) => QuoteCard(
quote:quote,
delete:(){
setState(() {
quotes.remove(quote);
});
}
)).toList(),
),
);
}
}
Card(
margin: EdgeInsets.fromLTRB(16, 16, 16, 0),
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Text(
quote.quote,
style: TextStyle(
fontSize: 18,
color: Colors.grey[600],
),
),
SizedBox(height: 10,),
Text(
quote.author,
style: TextStyle(
fontSize: 14,
color: Colors.grey[800],
),
),
SizedBox(height: 8.0,),
TextButton(
onPressed:(){
delete();
},
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Icon(Icons.delete),
Text(
'delete quote',
),
],
)
)
],
),
),
);
Try this one, it works
onPressed:(){
delete();
},

Flutter: Carrying over data from one file to another

I have two files...Workout.dart and Submit.dart. In Workout.dart I have variables: name, sets, rep, pmg, and smg. The use will input things for the variables and then once they click submit, a new page will open displaying the data. However, I don't know how to carry over that data. I'm new to Flutter and Dart, Please help!
Workout.dart
import 'package:flutter/material.dart';
import 'package:gyminprogress/Submit.dart';
class This extends StatefulWidget{
#override
Workout createState() => Workout();
}
class Workout extends State<This> {
String name , sets , rep , pmg , smg ;
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blueGrey,
appBar: AppBar(
title: Text('Create Workouts'),
centerTitle: true,
),
body: Container(
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(
children: <Widget>[
TextField(
decoration: InputDecoration(
hintText: 'Exercise Name'
),
style: TextStyle(color:Colors.white),
onChanged: (value){
setState(() {
name = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(
hintText: 'Primary Muscle Group'
),
style: TextStyle(color:Colors.white),
onChanged: (value){
setState(() {
pmg = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(
hintText: 'Secondary Muscle Group'
),
style: TextStyle(color:Colors.white),
onChanged: (value){
setState(() {
smg = value;
});
},
),SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(
hintText: 'Reps'
),
style: TextStyle(color:Colors.white),
onChanged: (value){
setState(() {
rep = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(
hintText: 'Sets'
),
style: TextStyle(color:Colors.white),
onChanged: (value){
setState(() {
sets = value;
});
},
),
Expanded(
child: Container(
child: Column(mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
RaisedButton(
color: Colors.cyan[200],
padding: EdgeInsets.symmetric(
horizontal: 80.0,
vertical: 20.0
,),
child: Text('Submit',style: TextStyle(
color: Colors.black,fontWeight: FontWeight.w200
),) ,
onPressed: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => Submit (
)),
);
},
),
]
),]),)
)
]
)
),
),
);
}
}
Submit.dart
import 'package:flutter/material.dart';
import 'package:gyminprogress/Workout.dart';
class Submit extends StatefulWidget{
#override
Enter createState() => Enter();
}
class Enter extends State<Submit> {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blueGrey,
appBar: AppBar(
title: Text('Create Workouts'),
centerTitle: true,
),
body: Container(
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(
children: <Widget>[
Text('Exercise Name : ${Workout.name}',
style: TextStyle(fontSize: 20.0,color: Colors.white, fontWeight: FontWeight.w200),),
Text('Primary Muscle Group : ${Workout.pmg} ',
style: TextStyle(fontSize: 20.0,color: Colors.white, fontWeight: FontWeight.w200),),
Text('Secondary Muscle Group : ${Workout.smg} ',
style: TextStyle(fontSize: 20.0,color: Colors.white, fontWeight: FontWeight.w200),),
Text('Reps : ${Workout.rep}',
style: TextStyle(fontSize: 20.0,color: Colors.white, fontWeight: FontWeight.w200),),
Text('Sets : ${Workout.sets}',
style: TextStyle(fontSize: 20.0,color: Colors.white, fontWeight: FontWeight.w200),),
]
)
)
)
);
}
}
To pass data from one widget to another you have to do two things,
Create a constructor of widget having data which it will accept,
Pass that data while calling it from another widget.
here is the code which solves your problem:
workout.dart
import "package:flutter/material.dart";
import './submit.dart';
class Workout extends StatefulWidget {
#override
_WorkoutState createState() => _WorkoutState();
}
class _WorkoutState extends State<Workout> {
String name, sets, rep, pmg, smg;
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Builder(
builder: (context) => Scaffold(
appBar: AppBar(
title: Text('Create Workouts'),
centerTitle: true,
),
body: Container(
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Scaffold(
body: Column(children: <Widget>[
TextField(
decoration: InputDecoration(hintText: 'Exercise Name'),
style: TextStyle(color: Colors.black),
onChanged: (value) {
setState(() {
name = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration:
InputDecoration(hintText: 'Primary Muscle Group'),
style: TextStyle(color: Colors.black),
onChanged: (value) {
setState(() {
pmg = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration:
InputDecoration(hintText: 'Secondary Muscle Group'),
style: TextStyle(color: Colors.black),
onChanged: (value) {
setState(() {
smg = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(hintText: 'Reps'),
style: TextStyle(color: Colors.black),
onChanged: (value) {
setState(() {
rep = value;
});
},
),
SizedBox(
height: 40.0,
),
TextField(
decoration: InputDecoration(hintText: 'Sets'),
style: TextStyle(color: Colors.black),
onChanged: (value) {
setState(() {
sets = value;
});
},
),
Expanded(
child: Container(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Row(
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
RaisedButton(
color: Colors.cyan[200],
padding: EdgeInsets.symmetric(
horizontal: 80.0,
vertical: 20.0,
),
child: Text(
'Submit',
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.w600),
),
onPressed: () {
//String name, sets, rep, pmg, smg;
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => Submit(
name: name,
sets: sets,
rep: rep,
pmg: pmg,
smg: smg,
),
),
);
},
),
]),
]),
))
]))),
),
),
),
);
}
}
submit.dart
import "package:flutter/material.dart";
class Submit extends StatelessWidget {
final String name, sets, rep, pmg, smg;
const Submit({
Key key,
this.name = "",
this.sets = "",
this.rep = "",
this.pmg = "",
this.smg = "",
}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.blueGrey,
appBar: AppBar(
title: Text('Create Workouts'),
centerTitle: true,
),
body: Container(
child: Padding(
padding: const EdgeInsets.all(20.0),
child: Column(children: <Widget>[
Text(
'Exercise Name : ${name}',
style: TextStyle(
fontSize: 20.0,
color: Colors.white,
fontWeight: FontWeight.w200),
),
Text(
'Primary Muscle Group : ${pmg} ',
style: TextStyle(
fontSize: 20.0,
color: Colors.white,
fontWeight: FontWeight.w200),
),
Text(
'Secondary Muscle Group : ${smg} ',
style: TextStyle(
fontSize: 20.0,
color: Colors.white,
fontWeight: FontWeight.w200),
),
Text(
'Reps : ${rep}',
style: TextStyle(
fontSize: 20.0,
color: Colors.white,
fontWeight: FontWeight.w200),
),
Text(
'Sets : ${sets}',
style: TextStyle(
fontSize: 20.0,
color: Colors.white,
fontWeight: FontWeight.w200),
),
]))));
}
}
Output:
New Updated code
Output:
You can pass data in the navigator.
class Workout extends ....> {
String name;
Person(this.name);
}
// Navigate to second screen with data
Navigator.push(context, new MaterialPageRoute(builder: (context) => new SecondScreenWithData(person: new Person("Vishal"))));
Then in the second screen
class SecondScreenWithData extends StatelessWidget {
// Declare a field that holds the Person data
final Person person;
// In the constructor, require a Person
SecondScreenWithData({Key key, #required this.person}) : super(key: key);
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text("Second Screen With Data"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
// Display passed data from first screen
Text("name: ${person.name}"),
RaisedButton(
child: Text("Back to previous screen"),
onPressed: () {
// Navigate back to first screen when tapped!
Navigator.pop(context);
}
),
],
)
),
);
}

The getter was called on a null

I am trying to show the progessbar until the data is fetched. At init state I have the api called. It shows the error as shown in the image and then the layouts are shown without showing the progress bar. I am new to flutter and could not get through this.
I have implemented as follows:
#override
void initState() {
super.initState();
getDetails();
}
GetDetails method
void getDetails() async {
setState(() {
_isLoading = true;
});
MenuDetailsResponse moreResponse = await getMenuDetails(widget.id);
if (moreResponse != null && moreResponse.data != null) {
setState(() {
details = moreResponse.data;
if (details.detail.maxQty != null) {
maxQtyController =
new TextEditingController(text: details.detail.maxQty.toString());
} else {
maxQtyController = new TextEditingController();
}
print(details);
_isLoading = false;
});
} else if (moreResponse != null) {
setState(() {
_isLoading = false;
});
showAlerts(context, "Sorry!!", moreResponse.message, AlertType.error);
} else {
setState(() {
_isLoading = false;
});
showAlerts(context, "Sorry!!",
"Something went wrong, Please try again later!!", AlertType.error);
}
}
Build Method:
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,
iconTheme: IconThemeData(color: Theme.of(context).primaryColor),
title: Text(
"Menu Details",
style: TextStyle(color: Theme.of(context).primaryColor),
),
),
body: Stack(
children: <Widget>[
Opacity(
opacity: _isLoading
? 0.3
: 1, // You can reduce this when loading to give different effect
child: AbsorbPointer(
absorbing: _isLoading,
child: _buildLayout(),
),
),
Opacity(
opacity: _isLoading ? 1.0 : 0,
child: Center(
child: CircularProgressIndicator(
backgroundColor: Theme.of(context).primaryColor,
),
)),
],
),
);
}
BuildLayout widget
Widget _buildLayout() {
return Container(
margin: EdgeInsets.all(10),
child: Wrap(
children: <Widget>[
Column(
children: <Widget>[
SizedBox(height: 20),
Text(
"Enter max quantity for today",
style: TextStyle(color: Theme.of(context).primaryColor),
),
SizedBox(height: 20),
_buildTopItems(),
],
)
],
),
);
}
Widget topItems
Widget _buildTopItems() {
return Container(
margin: EdgeInsets.only(top: 10),
child: Wrap(
children: <Widget>[
Row(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Container(
child: Image.network(
details.detail.image,
height: 150,
width: 150,
fit: BoxFit.fill,
),
),
SizedBox(
width: 10,
),
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
details.detail.name,
style: TextStyle(fontSize: 18),
),
SizedBox(height: 5),
Row(
children: <Widget>[
Text("Rs " + details.detail.price.toString(),
style: TextStyle(
decoration: TextDecoration.lineThrough)),
SizedBox(width: 5),
Text("Rs " + details.detail.discountPrice.toString(),
style: TextStyle(
fontSize: 17,
color: Theme.of(context).primaryColor,
))
],
),
SizedBox(height: 5),
Text(details.detail.foodtypedata.foodType),
SizedBox(height: 5),
StarRating(
rating: double.parse(details.detail.rating),
size: 24.0,
),
SizedBox(height: 5),
details.detail.status >= 1
? Text(
"Available",
style: TextStyle(
color: Theme.of(context).primaryColor),
)
: Text(
"UnAvailable",
style: TextStyle(color: Colors.red),
),
Text(
"- " + details.detail.createdAt,
textAlign: TextAlign.left,
),
],
))
]),
],
),
);
}
It appears to me that details is a class field and when build is called for the first time it will be null.
This happens because you are filling details on initState, but getDetails is an asynchronous call, so initState will execute and queue getDetails for later, as it's a Future, so it executes in the future, not right now. Right now Flutter goes to build and details is accessed there which is still null.
If you need data from a Future inside your build method, use a FutureBuilder.
I solved this by changing buildmethod as follows:
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,
iconTheme: IconThemeData(color: Theme.of(context).primaryColor),
title: Text(
"Menu Details",
style: TextStyle(color: Theme.of(context).primaryColor),
),
),
body: _isLoading
? Center(
child: CircularProgressIndicator(
backgroundColor: Theme.of(context).primaryColor,
),
)
: _buildLayout()
);
}

How can I show/hide menu items in Nav Drawer and enable/disable overflow menu items in App Bar programatically in Flutter?

I have been trying to do what the title says but have found no information on the web at all. In regular Android code, this is as simple as finding the ViewID of the drawer/toolbar, getting the menu item, and either calling .setEnabled() or .setVisible() on the menu item. How can I do this in Flutter? Basically when a certain url is loaded in webView, I want to either enable/disable or show/hide programatically (in the onLoadStart and onLoadFinished methods for webview_flutter). For reference, my scaffold:
return new Scaffold(
appBar: new AppBar(
title: new Text(appBarTitle),
actions: <Widget>[
IconButton(
icon: Icon(
Icons.refresh,
color: Colors.white,
),
onPressed: () {
webView.reload();
},
),
PopupMenuButton<Choice> ( //showchoice??
onSelected: _select,
itemBuilder: (BuildContext context) {
return choices.map((Choice choice) {
return PopupMenuItem<Choice>(
value: choice,
child: Text(choice.title),
);
}).toList();
},
),
],
),
drawer: Drawer(
child: ListView(
children: <Widget>[
new DrawerHeader(
child: Column (
crossAxisAlignment: CrossAxisAlignment.start,
mainAxisSize: MainAxisSize.max,
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget> [
Text(
'HLS Grades',
textAlign: TextAlign.left,
style: TextStyle(
color: Colors.white,
fontSize: 20,
),
),
Text(
'Canvas Online Grading System',
style: TextStyle(
color: Colors.white,
fontSize: 12,
),
),
]),
decoration: BoxDecoration(
color: Colors.blue,
),
),
Divider(),
Text(
'Course Actions',
style: TextStyle(
color: Colors.black,
fontSize: 12,
),
),
ListTile(
leading: Icon(MyFlutterApp.assignment),
title: Text('Assignments'),
onTap: () {
setState(() => _selectedDrawerIndex = 0);
_onSelectNavItem(0);
},
),
ListTile(
leading: Icon(MyFlutterApp.grades),
title: Text('Grades'),
onTap: () {
setState(() => _selectedDrawerIndex = 1);
_onSelectNavItem(1);
},
),
ListTile(
leading: Icon(MyFlutterApp.people),
title: Text('Users'),
onTap: () {
setState(() => _selectedDrawerIndex = 2);
_onSelectNavItem(2);
},
),
ListTile(
leading: Icon(MyFlutterApp.syllabus),
title: Text('Syllabus'),
onTap: () {
setState(() => _selectedDrawerIndex = 3);
_onSelectNavItem(3);
},
),
ListTile(
leading: Icon(MyFlutterApp.discussions),
title: Text('Discussions'),
onTap: () {
setState(() => _selectedDrawerIndex = 4);
_onSelectNavItem(4);
},
),
Divider(),
Text(
'App Actions',
style: TextStyle(
color: Colors.black,
fontSize: 12,
),
),
ListTile(
leading: Icon(MyFlutterApp.logout),
title: Text('Logout'),
onTap: () {
_onSelectNavItem(5);
},
),
ListTile(
leading: Icon(MyFlutterApp.settings),
title: Text('Settings'),
onTap: () {
_onSelectNavItem(6);
},
),
],
),
),
And the code for my choice class:
class Choice {
const Choice({this.title, this.icon});
final String title;
final IconData icon;
}
const List<Choice> choices = const <Choice>[
const Choice(title: 'All Grading Periods'),
const Choice(title: 'Trimester 1'),
const Choice(title: 'Trimester 2'),
const Choice(title: 'Trimester 3'),
];
class ChoiceCard extends StatelessWidget {
const ChoiceCard({Key key, this.choice}) : super(key: key);
final Choice choice;
#override
Widget build(BuildContext context) {
final TextStyle textStyle = Theme.of(context).textTheme.headline4;
return Card(
color: Colors.white,
child: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Icon(choice.icon, size: 128.0, color: textStyle.color),
Text(choice.title, style: textStyle),
],
),
),
);
}
}
Any help would be appreciated!
For whoever is stumped by this and is looking for an answer, just wrap your ListTile in a
Visibility (
visible: _visible
child: ListTile(...)
);
and whenever you want to remove, just
setState(() {
_visible = false;
});
or whenever you want to show
setState(() {
_visible = true;
});

How To Dynamically add Dropdown buttons or delete dropdown(s) in listview with flutter Web?

i have created a page where a user who will click a title to edit the contents and can add and delete devices that the article is attached to,
but i could not figure it out on how to program the drop down dynamically, to add more drop downs when a user press the add device button,
the additional function they want me to add as well is on the Dropdown list, when they select 'NONE' it should remove that dropdown as well,
i am planning to use mysql,xampp or sqlite for my database if im done with the UI,
import 'package:flutter/material.dart';
import 'package:surveyadminpanel/Contents/tabbar.dart';
import 'package:surveyadminpanel/widgets/button.dart';
import 'package:surveyadminpanel/widgets/simplewidgets.dart';
import 'homepage.dart';
import 'dart:ui';
class Item {
Item(this.name);
String name;
}
class editsurvey extends StatefulWidget {
#override
_editsurveyState createState() => _editsurveyState();
}
class _editsurveyState extends State<editsurvey>{
int surveyquestionnum = 1;
int surveyquestiontotal = 1;
List<Item> selectedUser = [null, null];
List<Item> selecteddata = [null, null];
List<Item> users;
int linkdevices = 1;
String dropdownvalue= "SELECT FROM DROPDOWN";
List data = [
'Sample Data 1',
'Sample Data 2',
'Sample Data 3',
'Sample Data 4',
'Sample Data 5',
'Sample Data 6',
];
#override
void initState() {
super.initState();
users = <Item>[
Item('Sample device 1'),
Item('Sample device 2'),
Item('Sample device 3'),
Item('Sample device 4'),
];
}
#override
Widget _dropdownbutton (List<Item> userlist, int index){
return Container(
padding: EdgeInsets.all(1),
width: MediaQuery.of(context).size.width,
decoration: BoxDecoration(
border: Border.all(),
borderRadius: BorderRadius.all(
Radius.circular(15.0) //
),
),
child: DropdownButton<Item>(
underline: SizedBox(),
isExpanded: true,
icon: Icon(Icons.arrow_drop_down),
hint: Text(" $dropdownvalue"),
value: selectedUser[index],
onChanged: (Item Value) {
setState(() {
selectedUser[index] = Value;
});
},
items: userlist.map((Item user) {
return DropdownMenuItem<Item>(
value: user,
child: Row(
children: <Widget>[
SizedBox(width: 10,),
Text(
user.name,
style: TextStyle(color: Colors.black),
),
],
),
);
}).toList(),
),
);
}
Widget _text(texthere,bold,size,color){
return Text(texthere,style: TextStyle(fontWeight: bold,fontSize: size,color: color),overflow: TextOverflow.ellipsis,maxLines: 1);
}
Widget _logo(){
return InkWell(
onTap: (){
Navigator.push(
context,
MaterialPageRoute(builder: (context) => admincontent()),
);
},
child: Container(width: 500,height: 200,child: Image.asset("images/v2.jpg")));
}
Widget build(BuildContext context) {
double screenHeight = MediaQuery.of(context).size.height;
double screenWidth = MediaQuery.of(context).size.width;
return Scaffold(
appBar: AppBar(
title: Padding(padding: EdgeInsets.only(left: 30),
child: RichText(
text: TextSpan(
text: 'Good Morning Welcome to Sample:',
style: TextStyle(
color: Colors.blueAccent, fontSize: 18),
children: <TextSpan>[
TextSpan(text: usernametitle,
style: TextStyle(
color: Colors.black, fontSize: 18),
)
]
),
)
),
elevation: 1,
automaticallyImplyLeading: false,
backgroundColor: Colors.white,
leading: _logo(),
actions: <Widget>[
IconButton(
icon: const Icon(Icons.notifications),
color: Colors.blueAccent,
tooltip: 'Show Notification',
onPressed: () {
},
),
IconButton(
color: Colors.lightGreen,
icon: const Icon(Icons.account_circle),
tooltip: 'Check your Profile',
onPressed: () {
},
),
],
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Container(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
SizedBox(height: 5),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
_text("EDIT SURVEY", FontWeight.bold, 20,Colors.blue),
roundedRectButton("BACK", signInGradients),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Container(
width: screenWidth/1.6,
height: screenHeight/1.6,
decoration: BoxDecoration(
color: Colors.orange[200],
borderRadius: new BorderRadius.all(new Radius.circular(20.0)),
),
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
_text("SURVEY TITLE", FontWeight.bold, 17,Colors.white),
_text(data[0], FontWeight.bold, 19, Colors.black),
_text("DATE CREATED", FontWeight.bold, 17,Colors.white),
_text(data[1], null, 19, Colors.black),
_text("CURRENT STATUS", FontWeight.bold, 17,Colors.white),
_text(data[2], null, 19, Colors.black),
_text("LANGUAGE VERSION", FontWeight.bold, 17,Colors.white),
_text(data[3], null, 19, Colors.black),
_text("NUMBERS OF ASSESSORS", FontWeight.bold, 17,Colors.white),
_text(data[4], null, 19, Colors.black),
_text("TOTAL RENDERED SURVEYS", FontWeight.bold, 17,Colors.white),
_text(data[5], null, 19, Colors.black),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
InkWell(
onTap: (){
},
child: Container(width: 100,height: 50,child: Text("EDIT SURVEY")),
),
_text("LINKED DEVICES : $linkdevices", FontWeight.bold, 17,Colors.white),
],
)
],
),
)
),
Container(
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
width: 1.0,
style: BorderStyle.solid
)
),
width: screenWidth/1.6,
height: screenHeight/1.6,
child: Column(
children: <Widget>[
_text("DEVICES PINNED", FontWeight.bold, 20,Colors.blue),
ListView.separated(
shrinkWrap: true,
itemCount: linkdevices,
itemBuilder: (context, index){
return Padding(
padding: const EdgeInsets.all(8.0),
child: _dropdownbutton(users, index),
);
},
separatorBuilder: (context, index) => Container(height: 10),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
InkWell(
child: roundedRectButton("ADD DEVICE", signInGradients),
onTap: (){
},
),
InkWell(
child: roundedRectButton("CLEAR ALL DEVICE", signInGradients),
onTap: (){
},
),
],
),
],
),
),
],
)
],
),
),
),
);
}
}
The Plan
The Result
im still trying to figure this out, but if someone can give me a lift,, im gonna be very thankful to who can help me out here ,,
You can copy paste run full code below
You can increase linkdevices and selectedUser
code snippet
List<Item> selectedUser = [null];
...
InkWell(
child: Text("ADD DEVICE"),
onTap: () {
selectedUser.add(null);
linkdevices ++;
setState(() {
});
working demo
full code
import 'package:flutter/material.dart';
class Item {
Item(this.name);
String name;
}
class editsurvey extends StatefulWidget {
#override
_editsurveyState createState() => _editsurveyState();
}
class _editsurveyState extends State<editsurvey> {
int surveyquestionnum = 1;
int surveyquestiontotal = 1;
List<Item> selectedUser = [null];
List<Item> selecteddata = [null, null];
List<Item> users;
int linkdevices = 1;
String dropdownvalue = "SELECT FROM DROPDOWN";
List data = [
'Sample Data 1',
'Sample Data 2',
'Sample Data 3',
'Sample Data 4',
'Sample Data 5',
'Sample Data 6',
];
#override
void initState() {
super.initState();
users = <Item>[
Item('Sample device 1'),
Item('Sample device 2'),
Item('Sample device 3'),
Item('Sample device 4'),
];
}
#override
Widget _dropdownbutton(List<Item> userlist, int index) {
return Container(
padding: EdgeInsets.all(1),
width: MediaQuery.of(context).size.width,
decoration: BoxDecoration(
border: Border.all(),
borderRadius: BorderRadius.all(Radius.circular(15.0) //
),
),
child: DropdownButton<Item>(
underline: SizedBox(),
isExpanded: true,
icon: Icon(Icons.arrow_drop_down),
hint: Text(" $dropdownvalue"),
value: selectedUser[index],
onChanged: (Item Value) {
print(Value.toString());
print(index);
setState(() {
selectedUser[index] = Value;
});
},
items: userlist.map((Item user) {
return DropdownMenuItem<Item>(
value: user,
child: Row(
children: <Widget>[
SizedBox(
width: 10,
),
Text(
user.name,
style: TextStyle(color: Colors.black),
),
],
),
);
}).toList(),
),
);
}
Widget _text(texthere, bold, size, color) {
return Text(texthere,
style: TextStyle(fontWeight: bold, fontSize: size, color: color),
overflow: TextOverflow.ellipsis,
maxLines: 1);
}
Widget _logo() {
return InkWell(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(builder: (context) => admincontent()),
);
},
child: Container(
width: 500, height: 200, child: Image.asset("images/v2.jpg")));
}
Widget build(BuildContext context) {
double screenHeight = MediaQuery.of(context).size.height;
double screenWidth = MediaQuery.of(context).size.width;
return Scaffold(
appBar: AppBar(
title: Padding(
padding: EdgeInsets.only(left: 30),
child: RichText(
text: TextSpan(
text: 'Good Morning Welcome to Sample:',
style: TextStyle(color: Colors.blueAccent, fontSize: 18),
children: <TextSpan>[
TextSpan(
text: "usernametitle",
style: TextStyle(color: Colors.black, fontSize: 18),
)
]),
)),
elevation: 1,
automaticallyImplyLeading: false,
backgroundColor: Colors.white,
leading: _logo(),
actions: <Widget>[
IconButton(
icon: const Icon(Icons.notifications),
color: Colors.blueAccent,
tooltip: 'Show Notification',
onPressed: () {},
),
IconButton(
color: Colors.lightGreen,
icon: const Icon(Icons.account_circle),
tooltip: 'Check your Profile',
onPressed: () {},
),
],
),
body: Padding(
padding: const EdgeInsets.all(16.0),
child: Container(
child: Column(
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
SizedBox(height: 5),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
_text("EDIT SURVEY", FontWeight.bold, 20.0, Colors.blue),
//roundedRectButton("BACK", signInGradients),
Text("BACK"),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceAround,
children: <Widget>[
Container(
width: screenWidth / 1.6,
height: screenHeight / 1.6,
decoration: BoxDecoration(
color: Colors.orange[200],
borderRadius:
new BorderRadius.all(new Radius.circular(20.0)),
),
child: Padding(
padding: const EdgeInsets.all(12.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
_text("SURVEY TITLE", FontWeight.bold, 17.0,
Colors.white),
_text(data[0], FontWeight.bold, 19.0, Colors.black),
_text("DATE CREATED", FontWeight.bold, 17.0,
Colors.white),
_text(data[1], null, 19.0, Colors.black),
_text("CURRENT STATUS", FontWeight.bold, 17.0,
Colors.white),
_text(data[2], null, 19.0, Colors.black),
_text("LANGUAGE VERSION", FontWeight.bold, 17.0,
Colors.white),
_text(data[3], null, 19.0, Colors.black),
_text("NUMBERS OF ASSESSORS", FontWeight.bold, 17.0,
Colors.white),
_text(data[4], null, 19.0, Colors.black),
_text("TOTAL RENDERED SURVEYS", FontWeight.bold,
17.0, Colors.white),
_text(data[5], null, 19.0, Colors.black),
Row(
mainAxisAlignment: MainAxisAlignment.spaceBetween,
children: <Widget>[
InkWell(
onTap: () {},
child: Container(
width: 100,
height: 50,
child: Text("EDIT SURVEY")),
),
_text("LINKED DEVICES : $linkdevices",
FontWeight.bold, 17.0, Colors.white),
],
)
],
),
)),
Container(
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
width: 1.0,
style: BorderStyle.solid)),
width: screenWidth / 1.6,
height: screenHeight / 1.6,
child: Column(
children: <Widget>[
_text("DEVICES PINNED", FontWeight.bold, 20.0,
Colors.blue),
ListView.separated(
shrinkWrap: true,
itemCount: linkdevices,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: _dropdownbutton(users, index),
);
},
separatorBuilder: (context, index) => Container(height: 10),
),
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
InkWell(
child: Text("ADD DEVICE"),
onTap: () {
selectedUser.add(null);
linkdevices ++;
setState(() {
});
/*listWidget.add( ListView.separated(
shrinkWrap: true,
itemCount: linkdevices,
itemBuilder: (context, index) {
return Padding(
padding: const EdgeInsets.all(8.0),
child: _dropdownbutton(users, index),
);
},
separatorBuilder: (context, index) => Container(height: 10),
));
setState(() {
});*/
},
),
InkWell(
child: Text("CLEAR ALL DEVICE"),
onTap: () {},
),
],
),
],
),
),
],
)
],
),
),
),
);
}
}
class admincontent extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Container();
}
}
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: editsurvey(),
);
}
}