The method 'MultiTrackTween' isn't defined for the type 'FadeAnimation'

user_16280483 0
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import 'package:flutter/material.dart';
import 'package:flutter/animation.dart';

class FadeAnimation extends StatelessWidget {
  final double delay;
  final Widget child;

  FadeAnimation(this.delay, this.child);

  ///build animation track
  @override
  Widget build(BuildContext context) {
    final tween = MultiTrackTween([
      Track("opacity")
          .add(Duration(milliseconds: 500), Tween(begin: 0.0, end: 1.0)),
      Track("translateY").add(
          Duration(milliseconds: 500), Tween(begin: -30.0, end: 0.0),
          curve: Curves.easeOut)
    ]);

    /// fade animation controller
    return ControlledAnimation(
      delay: Duration(milliseconds: (500 * delay).round()),
      duration: tween.duration,
      tween: tween,
      child: child,
      builderWithChild: (context, child, animation) => Opacity(
        opacity: animation["opacity"],
        child: Transform.translate(
            offset: Offset(0, animation["translateY"]), child: child),
      ),
    );
  }
}

When I am writing this code it is showing the method 'MultiTrackTween' isn't defined for the type 'FadeAnimation'. It is showing same error for Track, ControlledAnimation also. Please help.

flutter android-studio
2 Answers

currently the Methods has been changed. MultiTrackTween changed into MultiTween, ControlledAnimation changed into PlayAnimation and a few more. Please have a look at the below example:

// Create your Animation Example
enum AniProps { opacity, translateY }

class FadeAnimation extends StatelessWidget {
  final double delay;
  final Widget child;

  FadeAnimation(this.delay, this.child);

  @override
  Widget build(BuildContext context) {
    final tween = MultiTween<AniProps>()
        ..add(AniProps.opacity, Tween(begin: 0.0, end: 1.0))
        ..add(AniProps.translateY, Tween(begin: -30.0, end: 0.0), Duration(milliseconds: 500), Curves.easeOut);

    return PlayAnimation<MultiTweenValues<AniProps>>(
      delay: Duration(milliseconds: (500 * delay).round()),
      duration: tween.duration,
      tween: tween,
      child: child,
      builder: (context, child, animation) => Opacity(
        opacity: animation.get(AniProps.opacity),
        child: Transform.translate(
            offset: Offset(0, animation.get(AniProps.translateY)),
            child: child
        ),
      ),
    );
  }
}
user_63108900

MultiTrackTween The MultiTrackTween has been reworked into a new MultiTween. It has the same feature set but it's easier to use and fully type-safe.

Look at MultiTween README for further details.>>> https://pub.dev/packages/sa_multi_tween

user_151728240
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