Theme Data not applying in inherited classes - flutter

Question

I have declared a theme in main.dart , and it works fine as long as the context is used in main.dart but when I use Theme.of(context).primaryColor in the child class context doesn't pickup the theme.
Main.dart
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Expenso',
theme: ThemeData(
primarySwatch: Colors.green,
accentColor: Colors.amber
),
home: Expenso(),
);
}
}
class Expenso extends StatefulWidget {
#override
_ExpensoState createState() => _ExpensoState();
}
class _ExpensoState extends State<Expenso> {
final List<Transaction> _transactions=[
];
void _addTransaction(String txTitle,double txAmount)
{
final newTx=Transaction(
title: txTitle,
amount: txAmount,
id: DateTime.now().toString(),
date: DateTime.now()
);
setState(() {
_transactions.add(newTx);
});
}
void _startAddNewTransaction(BuildContext ctx) {
showModalBottomSheet(
context: ctx,
builder: (_) {
return GestureDetector(
onTap: () {},
child: NewTransaction(_addTransaction),
behavior: HitTestBehavior.opaque,
);
},
);
}
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
backgroundColor:Theme.of(context).primaryColor,
title: Text('Expenso'),
actions: <Widget>[
IconButton(
icon: Icon(Icons.add),
onPressed: () => _startAddNewTransaction(context),
)
],
),
body:SingleChildScrollView(
child: Column(
//mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Container(
width: double.infinity,
height: 50,
child: Card(
color: Colors.blue,
child: Text('chart')
)
),
TransactionList(_transactions)
],
),
),
floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed:() => _startAddNewTransaction(context),
backgroundColor: Theme.of(context).accentColor,
),
)
);
}
}
transaction_list.dart
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import '../models/transaction.dart';
class TransactionList extends StatelessWidget {
final List<Transaction> tractn;
TransactionList(this.tractn);
#override
Widget build(BuildContext context) {
return Container(
height: 500,
child :tractn.isEmpty? Column(
children: <Widget>[
Text('No Transaction added yet'),
SizedBox(
height: 20,
),
Container(
height:300,
child: Image.asset('assets/Images/waiting.png',
fit: BoxFit.cover,),
)
],
): ListView.builder(
itemBuilder: (ctx,index){
return Card(
child: Row(
children: <Widget>[
Container(
margin: EdgeInsets.symmetric(
vertical: 10,
horizontal: 15,
),
decoration: BoxDecoration(border: Border.all(
color: Theme.of(context).primaryColor,
width: 2,
style: BorderStyle.solid
)
),
padding: EdgeInsets.all(10),
child: Text(
'₹ ${tractn[index].amount.toStringAsFixed(2)}',
style: TextStyle(
fontWeight: FontWeight.bold,
fontStyle: FontStyle.italic ,
fontSize: 20,
color: Colors.green,
),
),
),
Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
tractn[index].title,
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 15,
color: Theme.of(context).primaryColor
),
),
Text(
DateFormat().format(tractn[index].date) ,
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 15,
color: Colors.grey
),),
Text(
tractn[index].id
)
],
)
],
),
);
},
itemCount: tractn.length,
)
);
}
}
Please guide me the way to implement the theme in inherited classes

Answer 1

I Agree with #Nolence comment.
If you are expecting to achieve the below result
Remove MaterialApp widget and make Scaffold as your primate return widget inside
class _ExpensoState
Sample Code:
import 'package:flutter/material.dart';
import 'package:flutter_app/Transaction.dart';
import 'transaction_list.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Expenso',
theme: ThemeData(
primarySwatch: Colors.green,
accentColor: Colors.amber
),
home: Expenso(),
);
}
}
class Expenso extends StatefulWidget {
#override
_ExpensoState createState() => _ExpensoState();
}
class _ExpensoState extends State<Expenso> {
final List<Transaction> _transactions=[
];
void _addTransaction(String txTitle,double txAmount)
{
final newTx=Transaction(
title: txTitle,
amount: txAmount,
id: DateTime.now().toString(),
date: DateTime.now()
);
setState(() {
_transactions.add(newTx);
});
}
void _startAddNewTransaction(BuildContext ctx) {
showModalBottomSheet(
context: ctx,
builder: (_) {
return GestureDetector(
onTap: () {},
child: NewTransaction(_addTransaction),
behavior: HitTestBehavior.opaque,
);
},
);
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor:Theme.of(context).primaryColor,
title: Text('Expenso'),
actions: <Widget>[
IconButton(
icon: Icon(Icons.add),
onPressed: () => _startAddNewTransaction(context),
)
],
),
body:SingleChildScrollView(
child: Column(
//mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: <Widget>[
Container(
width: double.infinity,
height: 50,
child: Card(
color: Colors.blue,
child: Text('chart')
)
),
TransactionList(_transactions)
],
),
),
floatingActionButtonLocation: FloatingActionButtonLocation.centerFloat,
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed:() => _startAddNewTransaction(context),
backgroundColor: Theme.of(context).accentColor,
),
);
}
}
If this is not what you wanted, please elaborate your question or comment below.

Answer 2

In the build method of your Expenso widget you define another MaterialApp, which creates its own default theme (different to your first theme). Remove that MaterialApp widget and it should work.