Starting a Welcome Screen on first startup - flutter

Question

I'm trying to display a few welcome screens on the first launch of my App. After which it will go to the login screen. But for efficiency, I need it to pop all the welcome screens off the 'stack' before launching the login screen, which is the reason behind this request.
My main.dart program loads into preloader2.dart which looks like this:
class PreLoad2 extends StatelessWidget {
#override
Widget build(BuildContext context) {
String myRoute;
return Scaffold(
body: SafeArea(
child: FlatButton(
child: Text('Press me!'),
onPressed: () {
if (loginCount == 0) { // globally defined variable
myRoute = '/welcome1';
} else {
myRoute = '/login';
}
++loginCount;
Navigator.pushNamed(context, myRoute);
},
),
),
);
}
}
It works perfectly well. But I have to click on the button.
I've tried both a stateless widget and a stateful one in preload2.
Can I write some code to replace the button so it just runs with no user input?

Answer 1

Just place the onPressed body into the build function before returning the Scaffold
#override
Widget build(BuildContext context) {
String myRoute;
if (loginCount == 0) // globally defined variable
myRoute = '/welcome1';
else
myRoute = '/login';
++loginCount;
Navigator.pushNamed(context, myRoute);
return Scaffold(
body: SafeArea(
child: FlatButton(
child: Text('Press me!'),
onPressed: () {
// Nothing Here
},
),
),
);
}
}

Answer 2

I have managed to get around, rather than answer my own question.
Inside my main.dart program I have added a new Welcome Widget. What this does is to set up a new Navigator that in turn calls each of my welcome screens. Each one in turn is pushed and then popped. So it is not quite what I was after but it definitely does the trick and appears to be quite efficient. My Welcome widget looks like this:
class Welcome extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Navigator(
initialRoute: 'welcome1',
onGenerateRoute: (RouteSettings settings) {
WidgetBuilder builder;
switch (settings.name) {
case 'welcome1':
builder = (BuildContext _) => Welcome1(
onWelcomeComplete: () {
Navigator.of(context).pop();
},
);
break;
case 'welcome2':
builder = (BuildContext _) => Welcome2(
onWelcomeComplete: () {
Navigator.of(context).pop();
},
);
break;
case 'welcome3':
builder = (BuildContext _) => Welcome3(
onWelcomeComplete: () {
Navigator.of(context).pop();
},
);
break;
case 'welcome4':
// Assume ChooseCredentialsPage collects new credentials and then
// invokes 'onSignupComplete()'.
builder = (BuildContext _) => Welcome4(
onWelcomeComplete: () {
Navigator.of(context).pop();
},
);
break;
default:
throw Exception('Invalid route: ${settings.name}');
}
return MaterialPageRoute(builder: builder, settings: settings);
},
);
}
}
Each of Welcome2(), Welcome3() and Welcome4() are held in their own files and pass back a link to the next widget, either going forward or backwards through the chain. The button code looks like this:
onPressed: () {
Navigator.of(context).pushReplacementNamed(routeName);
},
Where the route name is 'welcome2', for example, which is then linked to by the switch statement that creates a new route to the required widget.
Once on the last welcome screen (or before if required) the 'finish' button calls the onWelcomeComplete function which simply pops the complete Navigator stack leaving the code to follow the default route ('/') which I set up in the MyApp widget taking me to my Login() widget in login.dart. The code is:
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
initialRoute: '/welcome',
routes: {
'/': (BuildContext context) => Login(),
'/welcome': (BuildContext context) => Welcome(),
...
I hope this answer clearly explains what I have achieved and helps someone else.
Further information about the Flutter Navigator can be found here:
Navigator Class