Exception type Future(void) in not subtype of Future<AnimationController> - flutter

Question

the code below performs the creation of a layout in flutter, to create the layout I must first make sure that the set function is executed to make it use future builder but when I run the code I have the following error.
It tells me that the following error is present, future is not a subtype of future ,
theoretically both derive from object so there shouldn't be inheritance problems on dart, what is this due to?
Error:
type Future(void) in not subtype of Future
Flutter Code:
import ...
double latitudine=0;
Future<void> setValori() async {
latitudine=await Gps.getLatitudine();
print("Latitudine: "+latitudine.toString());
print("\n \n Sono dentro set valori \n \n");
}
class MediterranesnDietView extends StatelessWidget {
final AnimationController animationController;
final Animation animation;
const MediterranesnDietView(
{Key key, this.animationController, this.animation})
: super(key: key);
#override
Widget build(BuildContext context) {
return FutureBuilder<AnimatedBuilder>(
future: setValori(),
builder: (BuildContext context, AsyncSnapshot<AnimatedBuilder> snapshot) {
return AnimatedBuilder(
animation: animationController,
builder: (BuildContext context, Widget child) {
return FadeTransition(
opacity: animation,
child: new Transform(
transform: new Matrix4.translationValues(
0.0, 30 * (1.0 - animation.value), 0.0),
child: Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 16, bottom: 18),
child: Container(
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(8.0),
bottomLeft: Radius.circular(8.0),
bottomRight: Radius.circular(8.0),
topRight: Radius.circular(68.0)),
boxShadow: <BoxShadow>[
BoxShadow(
color: FintnessAppTheme.grey.withOpacity(0.2),
offset: Offset(1.1, 1.1),
blurRadius: 10.0),
],
),
child: Column(
children: <Widget>[
Padding(
padding:
const EdgeInsets.only(top: 16, left: 16, right: 16),
child: Row(
children: <Widget>[
Expanded(
child: Padding(
padding: const EdgeInsets.only(
left: 8, right: 8, top: 4),
child: Column(
children: <Widget>[
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#87A0E5')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Latitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/eaten.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(latitudine * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
),
SizedBox(
height: 8,
),
Row(
children: <Widget>[
Container(
height: 48,
width: 2,
decoration: BoxDecoration(
color: HexColor('#F56E98')
.withOpacity(0.5),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
),
Padding(
padding: const EdgeInsets.all(8.0),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.only(
left: 4, bottom: 2),
child: Text(
'Longitudine',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.1,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
Row(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.end,
children: <Widget>[
SizedBox(
width: 28,
height: 28,
child: Image.asset(
"assets/Home/burned.png"),
),
Padding(
padding:
const EdgeInsets.only(
left: 4, bottom: 3),
child: Text(
'${(102 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 16,
color: FintnessAppTheme
.darkerText,
),
),
),
Padding(
padding:
const EdgeInsets.only(
left: 8, bottom: 3),
child: Text(
'Kcal',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme
.fontName,
fontWeight:
FontWeight.w600,
fontSize: 12,
letterSpacing: -0.2,
color: FintnessAppTheme
.grey
.withOpacity(0.5),
),
),
),
],
)
],
),
)
],
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(right: 16),
child: Center(
child: Stack(
overflow: Overflow.visible,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: Container(
width: 100,
height: 100,
decoration: BoxDecoration(
color: FintnessAppTheme.white,
borderRadius: BorderRadius.all(
Radius.circular(100.0),
),
border: new Border.all(
width: 4,
color: FintnessAppTheme
.nearlyDarkBlue
.withOpacity(0.2)),
),
child: Column(
mainAxisAlignment:
MainAxisAlignment.center,
crossAxisAlignment:
CrossAxisAlignment.center,
children: <Widget>[
Text(
'${(1503 * animation.value).toInt()}',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.normal,
fontSize: 24,
letterSpacing: 0.0,
color: FintnessAppTheme
.nearlyDarkBlue,
),
),
Text(
'Kcal left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily:
FintnessAppTheme.fontName,
fontWeight: FontWeight.bold,
fontSize: 12,
letterSpacing: 0.0,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
],
),
),
),
Padding(
padding: const EdgeInsets.all(4.0),
child: CustomPaint(
painter: CurvePainter(
colors: [
FintnessAppTheme.nearlyDarkBlue,
HexColor("#8A98E8"),
HexColor("#8A98E8")
],
angle: 140 +
(360 - 140) *
(1.0 - animation.value)),
child: SizedBox(
width: 108,
height: 108,
),
),
)
],
),
),
)
],
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 8),
child: Container(
height: 2,
decoration: BoxDecoration(
color: FintnessAppTheme.background,
borderRadius: BorderRadius.all(Radius.circular(4.0)),
),
),
),
Padding(
padding: const EdgeInsets.only(
left: 24, right: 24, top: 8, bottom: 16),
child: Row(
children: <Widget>[
Expanded(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Carbs',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w500,
fontSize: 16,
letterSpacing: -0.2,
color: FintnessAppTheme.darkText,
),
),
Padding(
padding: const EdgeInsets.only(top: 4),
child: Container(
height: 4,
width: 70,
decoration: BoxDecoration(
color:
HexColor('#87A0E5').withOpacity(0.2),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
child: Row(
children: <Widget>[
Container(
width: ((70 / 1.2) * animation.value),
height: 4,
decoration: BoxDecoration(
gradient: LinearGradient(colors: [
HexColor('#87A0E5'),
HexColor('#87A0E5')
.withOpacity(0.5),
]),
borderRadius: BorderRadius.all(
Radius.circular(4.0)),
),
)
],
),
),
),
Padding(
padding: const EdgeInsets.only(top: 6),
child: Text(
'12g left',
textAlign: TextAlign.center,
style: TextStyle(
fontFamily: FintnessAppTheme.fontName,
fontWeight: FontWeight.w600,
fontSize: 12,
color: FintnessAppTheme.grey
.withOpacity(0.5),
),
),
),
],
),
),
...
),
),
),
);
},
);
});
}
}

Answer 1

The error indicates, that the Future you are giving the FutureBuilder does not match the Builders generic type.
You defined FutureBuilder<AnimatedBuilder> with the generic parameter AnimatedBuilder and it expects a Future<AnimatedBuilder>. The function setValori() is returning a Future<void>.
If you change your FutureBuilder<AnimatedBuilder> to FutureBuilder<void> and change AsyncSnapshot<AnimatedBuilder> to AsyncSnapshot<void>, you resolved the issues.

Answer 2

As your method setValori() returns a Future of type void you need to change the following line:
return FutureBuilder<AnimatedBuilder>
this should be
return FutureBuilder<void>