animated_value.dart

import 'package:flutter/material.dart';

typedef ValueTransitionBuilder = Widget Function(BuildContext context, Widget? child,double value);

class AnimatedValue extends ImplicitlyAnimatedWidget {
  /// Creates a widget that animates its rotation implicitly.
  ///
  /// The [value] argument must not be null.
  /// The [curve] and [duration] arguments must not be null.
  const AnimatedValue({
    super.key,
    required this.builder,
    required this.value,
    this.alignment = Alignment.center,
    this.filterQuality,
    super.curve,
    required super.duration,
    super.onEnd,
  });

  /// The widget below this widget in the tree.
  ///
  /// {@macro flutter.widgets.ProxyWidget.child}
  final ValueTransitionBuilder builder;

  /// The animation that controls the rotation of the child.
  ///
  /// If the current value of the turns animation is v, the child will be
  /// rotated v * 2 * pi radians before being painted.
  final double value;

  /// The alignment of the origin of the coordinate system in which the rotation
  /// takes place, relative to the size of the box.
  ///
  /// For example, to set the origin of the rotation to bottom middle, you can use
  /// an alignment of (0.0, 1.0).
  final Alignment alignment;

  /// The filter quality with which to apply the transform as a bitmap operation.
  ///
  /// {@macro flutter.widgets.Transform.optional.FilterQuality}
  final FilterQuality? filterQuality;

  @override
  ImplicitlyAnimatedWidgetState<AnimatedValue> createState() =>
      _AnimatedValueState();
}

class _AnimatedValueState extends ImplicitlyAnimatedWidgetState<AnimatedValue> {
  Tween<double>? _values;
  late Animation<double> _valueAnimation;

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

  @override
  void didUpdateTweens() {
    _valueAnimation = animation.drive(_values!);
  }

  @override
  Widget build(BuildContext context) =>
      AnimatedBuilder(animation: _valueAnimation, builder: (context, child) => widget.builder(context,child,_valueAnimation.value));
}