Flutter : scrollController.isAttached is always false - flutter

Question

How can I scroll to a special widget in a ListView? For example, I want to automatically scroll to some container in ListView if I press a certain button on a previous screen. I will pass to the next screen an Id (from id I will know the index) and when I navigate to the next screen I want to automatically scroll to this widget.
the code in main screen : Navigator.push(context, MaterialPageRoute(builder: (_) => CreatedEstatesScreen(estateId: id)));
the code in the next screen :
class RecentEstateOrdersScreen extends StatefulWidget {
static const String id = "RecentEstateOrdersScreen";
String? estateId;
RecentEstateOrdersScreen({Key? key, this.estateId}) : super(key: key);
#override
_RecentEstateOrdersScreenState createState() =>
_RecentEstateOrdersScreenState();
}
class _RecentEstateOrdersScreenState extends State<RecentEstateOrdersScreen> {
late RecentEstatesOrdersBloc _recentEstatesOrdersBloc;
late ItemScrollController scrollController;
late ItemPositionsListener itemPositionsListener;
String? userToken;
List<EstateOrder> orders = [];
#override
void initState() {
super.initState();
_recentEstatesOrdersBloc = RecentEstatesOrdersBloc(EstateOrderRepository());
_onRefresh();
User? user = BlocProvider.of<UserLoginBloc>(context).user;
if (user != null && user.token != null) {
userToken = user.token;
}
scrollController = ItemScrollController();
itemPositionsListener = ItemPositionsListener.create();
}
_onRefresh() {
if (BlocProvider.of<UserLoginBloc>(context).user!.token != null) {
_recentEstatesOrdersBloc.add(
RecentEstatesOrdersFetchStarted(
token: BlocProvider.of<UserLoginBloc>(context).user!.token!),
);
}
}
#override
Widget build(BuildContext context) {
return SafeArea(
child: Scaffold(
appBar: AppBar(
title: Text(
AppLocalizations.of(context)!.recent_created_orders,
),
),
body: BlocConsumer<RecentEstatesOrdersBloc, RecentEstatesOrdersState>(
bloc: _recentEstatesOrdersBloc,
listener: (context, recentOrdersState) async {
if (recentOrdersState is RecentEstatesOrdersFetchError) {
var error = recentOrdersState.isConnectionError
? AppLocalizations.of(context)!.no_internet_connection
: recentOrdersState.error;
await showWonderfulAlertDialog(
context, AppLocalizations.of(context)!.error, error);
}
},
builder: (BuildContext context, recentOrdersState) {
if (recentOrdersState is RecentEstatesOrdersFetchProgress) {
return const ClientsOrdersShimmer();
}
if (recentOrdersState is! RecentEstatesOrdersFetchComplete) {
return Container();
}
orders = recentOrdersState.estateOrders;
if (orders.isEmpty) {
return Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
SvgPicture.asset(
documentOutlineIconPath,
width: 0.5.sw,
height: 0.5.sw,
color: Theme.of(context)
.colorScheme
.onBackground
.withOpacity(0.42),
),
48.verticalSpace,
Text(
AppLocalizations.of(context)!.have_not_recent_orders,
style: Theme.of(context).textTheme.headline4,
),
],
),
);
}
if (widget.estateId != null) {
SchedulerBinding.instance!.addPostFrameCallback((_) {
jumpToOrder(orders);
});
}
return RefreshIndicator(
color: Theme.of(context).colorScheme.primary,
onRefresh: () async {
_onRefresh();
},
child: ListView.builder(
itemCount: orders.length,
itemBuilder: (_, index) {
return EstateOrderCard(
estateOrder: orders.elementAt(index),
);
}),
);
},
),
),
);
}
jumpToOrder(List<EstateOrder> orders) {
int index = getIndexFromId(orders);
if (index != -1) {
if (scrollController.isAttached) {
scrollController.scrollTo(
index: index,
duration: const Duration(seconds: 2),
curve: Curves.easeInOutCubic);
}
}
}
getIndexFromId(List<EstateOrder> orders) {
for (int i = 0; i < orders.length; i++) {
if (orders.elementAt(i).id == int.parse(widget.estateId!)) {
return i;
}
}
return -1;
}
}```

Answer 1

If you are using the library then you have to use ScrollablePositionedList.builder, not the normal ListView.builder.