I want to get the sum total of the price of all the products in a list of cards with data from firestore - flutter

Question

I want to get the sum total of the price of all the products in a list of cards with data from firestore and i don't how to do that on flutter.
This is the where i show the cards and where i want to show the total price too:
class ShopListPage extends StatelessWidget {
const ShopListPage({super.key});
Stream<List<ShopList>> readProducts() => FirebaseFirestore.instance
.collection('shoplist')
.orderBy('price')
.snapshots()
.map((snapshot) =>
snapshot.docs.map((doc) => ShopList.fromJson(doc.data())).toList());
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Theme.of(context).colorScheme.background,
body: StreamBuilder<List<ShopList>>(
stream: readProducts(),
builder: (context, snapshot) {
if (snapshot.hasError) {
return Text('Algo ha ocurrido! ${snapshot.error}');
} else if (snapshot.hasData) {
final shoplist = snapshot.data!;
return ListView(
children: shoplist
.map((p) => BuildListCards(shopList: p))
.toList());
} else {
return const Center(child: CircularProgressIndicator());
}
}),
floatingActionButton: FloatingActionButton(
child: const Icon(
Icons.paid,
),
onPressed: () {},
),
);
}
}
The BuildListCard Class: here is where i show the price individually
class BuildListCards extends StatelessWidget {
final ShopList shopList;
const BuildListCards({Key? key, required this.shopList}) : super(key: key);
#override
Widget build(BuildContext context) {
return Card(
margin: const EdgeInsets.all(8),
clipBehavior: Clip.hardEdge,
child: ConstrainedBox(
constraints: const BoxConstraints(maxHeight: 80),
child: Row(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
Image(
image: NetworkImage(shopList.imageUrl),
fit: BoxFit.cover,
),
Padding(
padding: const EdgeInsets.all(8),
child: Column(
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(shopList.name),
Text('Precio: ${shopList.price}\$'),
Text('Cantidad: ${shopList.quantity}')
],
),
),
const Spacer(),
Padding(
padding: const EdgeInsets.fromLTRB(0, 25, 8, 0),
child: ElevatedButton(
style: ButtonStyle(
foregroundColor: MaterialStateProperty.all<Color>(
const Color(0xFFFFFFFF),
),
backgroundColor: MaterialStateProperty.all<Color>(
const Color(0xFF6750A4),
),
),
onPressed: () => showDialog(
context: context,
barrierDismissible: false,
builder: (BuildContext context) => AlertDialog(
title: Text(
'¿Desea eliminar el producto ${shopList.name} de la base de datos?',
textAlign: TextAlign.center,
),
actions: <Widget>[
TextButton(
onPressed: () {
Navigator.pop(context);
},
child: const Text('Cancelar')),
TextButton(
onPressed: () {
final docShopList = FirebaseFirestore.instance
.collection('shoplist')
.doc(shopList.id);
docShopList.delete();
Navigator.pop(context);
},
child: const Text('Eliminar')),
],
),
),
child: const Text(
'Eliminar',
),
),
),
],
),
),
);
}
}
i want to calculate the sum total of the price, i use shoplist.price to show the price