Flutter Randomizing - How to prevent from displaying the previous element shown - flutter

Question

Upon clicking, my app shows either yes, no, or maybe. How do I set the subsequent result strictly different from the previous one? For example, the current result is 'no', how do I randomize and make sure that the next result would ONLY either be 'yes' or 'maybe'?
This is the code
import 'package:flutter/material.dart';
import 'dart:math';
void main() => runApp(
MaterialApp(
debugShowCheckedModeBanner: false,
home: MyApp(),
),
);
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Welcome to Flutter',
home: Scaffold(
backgroundColor: Colors.white,
appBar: AppBar(
centerTitle: true,
title: Text(
'Ask Me Anything',
style: TextStyle(fontFamily: 'Lobster', fontSize: 25),
),
),
body: picker(),
),
);
}
}
class picker extends StatefulWidget {
#override
_pickerState createState() => _pickerState();
}
class _pickerState extends State<picker> {
List yourList = ["Yes", "No", "Maybe"];
int randomIndex;
_pickerState() {
randomIndex = Random().nextInt(yourList.length);
}
#override
Widget build(BuildContext context) {
return Center(
child: TextButton(
onPressed: () {
setState(() {
randomIndex = Random().nextInt(yourList.length);
print("What's showing is '${yourList[randomIndex]}'");
});
},
child: Stack(
children: <Widget>[
Center(child: Image.asset('images/blu.png')),
Center(
child: Text(
yourList[randomIndex],
style: TextStyle(fontSize: 40, fontFamily: 'Lobster'),
),
),
],
),
),
);
}
}

Answer 1

You could just do a while loop which keeps trying for a new answer as long as the answer is equal to the current answer:
_pickerState() {
oldIndex = randomIndex;
randomIndex = Random().nextInt(yourList.length);
while (oldIndex == randomIndex){
randomIndex = Random().nextInt(yourList.length);
}
And then in your onPressed:
setState(() {
randomIndex = _pickerState();
print("What's showing is '${yourList[randomIndex]}'");
});