AnimatedCount

gistfile1.txt

import 'package:flutter/material.dart';

class AnimatedCount extends ImplicitlyAnimatedWidget {
  const AnimatedCount({
    super.key,
    required this.count,
    super.duration = const Duration(milliseconds: 600),
    super.curve = Curves.fastOutSlowIn,
    required this.formatter,
    this.style,
  });

  final double count;
  final String Function(double) formatter;
  final TextStyle? style;

  @override
  ImplicitlyAnimatedWidgetState<ImplicitlyAnimatedWidget> createState() {
    return _AnimatedCountState();
  }
}

class _AnimatedCountState extends AnimatedWidgetBaseState<AnimatedCount> {
  late Tween<double> _doubleCount;

  @override
  void initState() {
    _doubleCount = Tween<double>(begin: widget.count, end: widget.count);
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Text(widget.formatter(_doubleCount.evaluate(animation)),
        style: widget.style);
  }

  @override
  void forEachTween(TweenVisitor<dynamic> visitor) {
    _doubleCount = visitor(
      _doubleCount,
      widget.count,
      (dynamic value) => Tween<double>(begin: value),
    ) as Tween<double>;
  }
}