Tween animation flutter - flutter

Question

I want to play an animation when a button is clicked. On the first press, the widget rotates 180 degrees, on the second press, another 180 degrees (that is, it returns to its original position). How can I do this?
Simulated gesture detector button
Expanded(
child: GestureDetector(
onTap: () => setState(() {
if (tapValue == 0) {
tapValue++;
animController.forward();
beginValue = 0.0;
endValue = 0.5;
} else {
tapValue--;
animController.forward();
}
}),
child: Container(
child: Image.asset('assets/images/enableAsset.png'),
),
),
),
The widget I want to rotate
child: CustomPaint (
painter: SmileyPainter(),
child: RotationTransition(
turns: Tween(begin: beginValue, end: endValue,).animate(animController),
child: CustomPaint (
painter: Smile(),
),
),
)
animation controller
#override
void initState() {
animController = AnimationController(
duration: const Duration(milliseconds: 400),
vsync: this,
);
super.initState();
}

Answer 1

If what you want to achieve is only to rotate a widget, I would recommend avoiding a controller. Not only will this simplify your code but it will also save you the chore of disposing it.
I have come to realize that pretty much any controller can be avoided using the TweenAnimationBuilder widget.
Here is an example of how to to make it work for your case:
Scaffold(
floatingActionButton: FloatingActionButton(
onPressed: () {
_rotationAngle += pi;
print(_rotationAngle);
setState(() {
});
},
),
body: Center(
child: TweenAnimationBuilder(
duration: Duration(milliseconds: 300),
tween: Tween<double>(begin: 0, end: _rotationAngle),
builder: (BuildContext context, double value, Widget child) {
return Transform.rotate(
angle: value,
child: child,
);
},
child: Container(
height: 500,
width: 50,
color: Colors.redAccent,
),
),
),
);

Answer 2

just replace
else {tapValue--;
animController.forward();
}
to
else {tapValue--;
animController.reverce();
}