Flutter close child screen and navigate to another screen automatically - flutter

Question

I'm using bottom tab-navigation and my screens have the following logic:
Screen A
-> Button Open Screen B
-> Button Open Screen C
Screen B
-> Button Open Child Screen B
-> Button Open Screen C
I can navigate from Screen A to Screen B through code using widget.mainTabController.animateTo(1); and it works great.
What I need now is to navigate from Screen B to Screen A after the Child Screen B has been closed.
class ScreenB extends StatefulWidget {
final TabController mainTabController;
ScreenB(TabController mainTabController)
: this.mainTabController = mainTabController;
#override
_State createState() => _State();
}
class _State extends State<ScreenB>
{
#override
Widget build(BuildContext context) {
// ...
GridView.builder(
// ...
itemBuilder: (BuildContext context, int index)
{
Entry entry = this.entries[index];
return entry.build(context);
}
);
}
}
class Entry extends State<ScreenB>
{
Widget build(BuildContext context)
{
// ...
onTap: () async {
// Opens the Screen B Child
final result = await Navigator.push(
context,
MaterialPageRoute(
builder: (context) => ScreenBChild(),
),
);
// Should go back to Screen A but does nothing
if (result)
widget.mainTabController.animateTo(0);
);
}
}
After the screen "Child Screen B" has been closed, I'm back to Screen B and the code widget.mainTabController.animateTo(0), although is being triggered, nothing happens, the screen doesn't change. Also no error is thrown in the console.

Answer 1

Solved.
The Entry class must be converted into a Stateless (or Stateful, as you wish) class
The class should receive the mainTabController upon its initialization
We have to apply a Delay before trigger the animation to move to another screen
With that said, the Entry is called like this:
Entry entry = new Entry(mainTabController: widget.mainTabController);
And the class was converted to:
class Entry extends StatelessWidget {
final TabController mainTabController;
Entry({Key key, this.mainTabController}) : super(key: key);
#override
Widget build(BuildContext context)
{
// ...
onTap: () async {
final result = await Navigator.push(
context,
MaterialPageRoute(
builder: (context) => ScreenBChild(),
),
);
if (result)
{
await Future.delayed(Duration(milliseconds: 300), () =>
{
this.mainTabController.animateTo(0);
});
}
}
}
}