Flutter: update page before running method in setState() - flutter

Question

I need the run a method in a setState() after some previous variables in the same setState() have been updated. At the moment it waits for the method to complete before updating the page.
(I'm new to Flutter and my programming skills aren't very good).
I have tried splitting the setState() into different ones:
// this method is called once the animation has finished
void _solve() {
setState(() {
_isSolving = true; // I need to update the display here
});
setState(() {
_solution = PuzzleSolver().solve(); // this takes some time and returns a map
});
setState(() {
_isSolving = false; // and I need to update the display again here
});
}
But this didn't help, because I don't really know how it all works.
Here's the stripped down version of the code:
import 'package:flutter/material.dart';
import './puzzleSolver.dart';
class SomePage extends StatefulWidget {
#override
_SomePageState createState() => _SomePageState();
}
class _SomePageState extends State<SomePage> with TickerProviderStateMixin {
AnimationController animationController;
Map _solution = {};
bool _isSolving = false;
void initState() {
super.initState();
animationController = AnimationController(
vsync: this, duration: Duration(seconds: 5))
..addStatusListener(
(state) => (state == AnimationStatus.dismissed) ? _solve() : null); // run _solve() once the animation has finished
animationController.reverse();
}
// this method is called once the animation has finished
void _solve() {
setState(() {
_isSolving = true; // I need to update the display here
_solution = PuzzleSolver().solve(); // this takes some time and returns a map
_isSolving = false; // and I need to update the display here again
});
// at the moment it updates the display here
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Some Page'),
),
body: Column(
children: <Widget>[
(_isSolving == false && _solution.isEmpty)
? Text('hello world') // only show when it's not solving and there is no solution
: RaisedButton(
child: Text('show solution'),
onPressed: (_isSolving)
? null // disable the button when its solving
: () {}, // enable it when its solved
),
AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return Container(); // this is where the animated widgets would be
}
),
],
),
);
}
}

Answer 1

Assuming the PuzzleSolver().solve() method is a Future, you can do the following:
void _solve() async{
setState(() {
_isSolving = true;
});
_solution = await PuzzleSolver().solve(); // waits for the future to finish
setState(() {
_isSolving = false;
});