Showing snackbar from alert dialog - flutter

Question

I'm at a loss with this one. So I know that to show a snack bar, you have to have access to a build context whose ancestor is a scaffold. To solve this I usually just make a separate widget within the scaffold within which a new build context can be called. However, I can't seem to get this to work when I use an alert dialog.
The 'child' widget i've made under the scaffold looks like this:
class DeleteButton extends StatelessWidget {
DeleteButton({#required this.vm, #required this.popCallback});
final AddJobVM vm;
final Function popCallback;
#override
Widget build(BuildContext context) {
final continueCallBack = () async {
print("deleting ${vm.jobName}");
ToasterBundle toast;
toast = await vm.deleteJob();
print(toast.success);
Scaffold.of(context).showSnackBar(generateSnackBar(toast));
await Future.delayed(
Duration(seconds: 2),
);
if (toast.success) {
popCallback();
}
};
return Padding(
padding: EdgeInsets.only(right: kStandardPadding),
child: GestureDetector(
onTap: () {
showDialog(
context: context,
builder: (context) {
return AlertDialogueBlurredBG(
title: 'Delete Job',
content: 'Are you sure you want to delete this job?',
continueCallBack: continueCallBack,
);
});
},
child: Icon(
Icons.delete_outline,
color: kColorWhite,
size: 28,
),
),
);
}
}
But I'm getting an error when I call the 'continueCallBack':
[VERBOSE-2:ui_dart_state.cc(157)] Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
At this point the state of the widget's element tree is no longer stable.
To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.
#0 Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:3781:9)
#1 Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:3795:6)
#2 Element.findAncestorStateOfType (package:flutter/src/widgets/framework.dart:3914:12)
#3 Scaffold.of (package:flutter/src/material/scaffold.dart:1453:42)
#4 DeleteButton.build.<anonymous closure> (package:upworkv2/screens/jobs/add_edit_job_screen.dart:615:16)
<asynchronous suspension>
#5 DeleteButton.build.<anonymous closure> (package:upworkv2/screens/jobs/add_edit_job_scree<…>
I would have thought that using a call back which references the build context outside of the alert dialog would have worked but no dice. Any ideas on where I'm going wrong here?

Answer 1

Builder Widget will help in this case, just see How I use & implement it,
body: Builder(
builder: (BuildContext innerContext) {
return RaisedButton(
onPressed: () {
showDialog(
context: context,
builder: (context) => AlertDialog(
title: Text('Are you sure?'),
content: Text('Do you want to go to background?'),
actions: <Widget>[
FlatButton(
onPressed: () => Navigator.of(context).pop(),
child: Text('NO')),
FlatButton(
onPressed: () {
Scaffold.of(innerContext).showSnackBar(SnackBar(
content: Text('Added added into cart'),
duration: Duration(seconds: 2),
action:
SnackBarAction(label: 'UNDO', onPressed: () {}),
));
},
child: Text('YES'))
],
),
);
},
);
},
),
This exception happens because you are using the context of the widget that instantiated Scaffold. Not the context of a child of Scaffold.
Output: