how to append the callback data to Text widget flutter - flutter

Question

In my page I have to open dialog and in that dialog we have to show listview of data. Once the user click any item in listview he have to show the item data to listview. I am using callback here. Can any one tell me how to pass the data to page (Text widget) .
code:
class PosSettingsPage extends StatefulWidget {
const PosSettingsPage({Key? key}) : super(key: key);
#override
State<StatefulWidget> createState() => _PosSettingPageState();
}
class _PosSettingPageState extends State<PosSettingsPage> {
#override
Widget build(BuildContext context) {
printerTerminalType = _documentService.hardware.paymentTerminalType.name;
return Scaffold(
........
........
InkWell(
onTap: () {
**openAppDialog(
context,
_buildContentDialog(
context, PaymentTerminalTypeName));**
},
child: Container(
margin: const EdgeInsets.only(left: 25),
width: 300,
decoration: BoxDecoration(
border: Border.all(color: Colors.white),
borderRadius: const BorderRadius.all(
Radius.circular(5),
),
),
child: Padding(
padding: const EdgeInsets.all(10.0),
/// This Text widget
child: Text(
printerTerminalType,
style: Theme.of(context)
.textTheme
.headline1
?.copyWith(color: Colors.white),
),
),
),
),
}
AppDialog _buildContentDialog(BuildContext context, List<String> data) {
return AppDialog(
dataList: data,
onValueChanged: (text) {
/// I want to append this "text" to text widget
},
);
}
}
class AppDialog extends StatefulWidget {
List<String> dataList = [];
final ValueChanged<String> onValueChanged;
AppDialog({
Key? key,
required this.dataList,
required this.onValueChanged,
}) : super(key: key);
#override
State<StatefulWidget> createState() => _AppDialogState();
}
class _AppDialogState extends State<AppDialog> {
TextEditingController editingController = TextEditingController();
final List<String>? items = [];
#override
void initState() {
items?.addAll(widget.dataList);
super.initState();
}
void filterSearchResults(String query) {
List<String> dummySearchList = <String>[];
dummySearchList.addAll(widget.dataList);
if (query.isNotEmpty) {
List<String> dummyListData = <String>[];
for (var item in dummySearchList) {
if (item.contains(query)) {
dummyListData.add(item);
}
}
setState(() {
items?.clear();
items?.addAll(dummyListData);
});
return;
} else {
setState(() {
items?.clear();
items?.addAll(widget.dataList);
});
}
}
#override
Widget build(BuildContext context) {
return Dialog(
child: SizedBox(
width: 500,
height: 400,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
mainAxisSize: MainAxisSize.max,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: TextField(
onChanged: (value) {
filterSearchResults(value);
},
controller: editingController,
decoration: const InputDecoration(
hintText: "Search list",
hintStyle: TextStyle(fontSize: 12.0, color: Colors.white24),
),
),
),
Expanded(
child: SizedBox(
height: MediaQuery.of(context).size.height,
child: ListView.builder(
shrinkWrap: true,
itemCount: items?.length,
itemBuilder: (context, index) {
return ListTile(
onTap: (){
widget.onValueChanged.call(items![index].toString());
Navigator.pop(context);
},
title: Text(items![index],style: Theme.of(context).textTheme.headline5,),
);
},
),
),
),
Align(
alignment: Alignment.bottomCenter,
child: Container(
margin: const EdgeInsets.all(10.0),
width: double.infinity,
child: Center(
child: Text(
'Cancel',
style: Theme.of(context).textTheme.subtitle1,
),
),
),
)
],
),
),
);
}
}
Future<void> openAppDialog(BuildContext context, Widget appDialog,) async {
return showDialog<dynamic>(
context: context,
builder: (BuildContext context) {
return appDialog;
},
);
}