Flutter - AnimatedScale not animating when widget update - flutter

Question

I have a rating widget with 5 stars.
I can give a rating by dragging.
I want to animate the star with the star rating so that the scale gets bigger and the star without the star rating gets smaller again.
Therefore, I made sure that the star with the star rating is created using the AnimatedScale.
However, as you can see in the attached gif, the size of the star changes but it is not animated.
I gave the Duration value of the AnimatedScale property to 2 seconds, but it is being changed as soon as it is graded.
How can the stars grow and shrink smoothly?
Here is my code
import 'package:flutter/material.dart';
typedef void RatingChangeCallback(double rating);
class SmoothStarRating extends StatelessWidget {
final int starCount;
final double rating;
final RatingChangeCallback onRatingChanged;
final Color? color;
final Color? borderColor;
final double size;
final double spacing;
SmoothStarRating({
this.starCount = 5,
this.spacing = 0.0,
this.rating = 0.0,
required this.onRatingChanged,
this.color,
this.borderColor,
this.size = 25,
});
Widget getIcon(int starIndex) {
if (starIndex >= rating) {
return Icon(Icons.star_border, color: borderColor, size: size);
} else if (starIndex > rating - 0.5 && starIndex < rating) {
return AnimatedScale(
duration: Duration(seconds: 2),
scale: 1.1,
child: Icon(Icons.star_half, color: color, size: size),
);
} else {
return AnimatedScale(
duration: Duration(seconds: 2),
scale: 1.1,
child: Icon(Icons.star, color: color, size: size),
);
}
}
Widget buildStar(BuildContext context, int starIndex) {
return GestureDetector(
onTap: () {
onRatingChanged(starIndex + 1.0);
},
onHorizontalDragUpdate: (dragDetails) {
RenderBox box = context.findRenderObject() as RenderBox;
var _pos = box.globalToLocal(dragDetails.globalPosition);
var newRating = _pos.dx / size;
if (newRating > starCount) newRating = starCount.toDouble();
if (newRating < 0) newRating = 0.0;
onRatingChanged(newRating);
},
child: getIcon(starIndex),
);
}
#override
Widget build(BuildContext context) {
return Wrap(
alignment: WrapAlignment.start,
spacing: spacing,
children: List.generate(starCount, (starIndex) => buildStar(context, starIndex)),
);
}
}
+ ADDITIONAL
I tried implementing it using animation_controller, but the results are the same.
import 'package:flutter/material.dart';
typedef void RatingChangeCallback(double rating);
class SmoothStarRating extends StatefulWidget {
final int starCount;
final double rating;
final RatingChangeCallback onRatingChanged;
final Color? color;
final Color? borderColor;
final double size;
final double spacing;
SmoothStarRating({
this.starCount = 5,
this.spacing = 0.0,
this.rating = 0.0,
required this.onRatingChanged,
this.color,
this.borderColor,
this.size = 25,
});
#override
State<SmoothStarRating> createState() => _SmoothStarRatingState();
}
class _SmoothStarRatingState extends State<SmoothStarRating> with TickerProviderStateMixin {
late final AnimationController _controller = AnimationController(
duration: const Duration(milliseconds: 500),
vsync: this,
)..forward();
late final Animation<double> _animation = Tween(begin: 1.0, end: 1.1).animate(_controller);
#override
void dispose() {
_controller.dispose();
super.dispose();
}
Widget getIcon(int starIndex) {
if (starIndex >= widget.rating) {
return Icon(Icons.star_border, color: widget.borderColor, size: widget.size);
} else if (starIndex > widget.rating - 0.5 && starIndex < widget.rating) {
return Icon(Icons.star_half, color: widget.color, size: widget.size);
} else {
return ScaleTransition(
scale: _animation,
child: Icon(Icons.star, color: widget.color, size: widget.size),
);
}
}
Widget buildStar(BuildContext context, int starIndex) {
return GestureDetector(
onTap: () {
widget.onRatingChanged(starIndex + 1.0);
},
onHorizontalDragUpdate: (dragDetails) {
RenderBox box = context.findRenderObject() as RenderBox;
var _pos = box.globalToLocal(dragDetails.globalPosition);
var newRating = _pos.dx / widget.size;
if (newRating > widget.starCount) newRating = widget.starCount.toDouble();
if (newRating < 0) newRating = 0.0;
widget.onRatingChanged(newRating);
},
child: getIcon(starIndex),
);
}
#override
Widget build(BuildContext context) {
return Wrap(
alignment: WrapAlignment.start,
spacing: widget.spacing,
children: List.generate(widget.starCount, (starIndex) => buildStar(context, starIndex)),
);
}
}