animation method

@override List<AnimationController> animation()

Method to init the animation controllers

Implementation

@override
List<AnimationController> animation() {
  var controllers = <AnimationController>[];

  for (var i = 0; i < 3; i++) {
    AnimationController sizeController = AnimationController(
        duration: const Duration(milliseconds: 375), vsync: state);
    var delayedAnimation =
        Tween(begin: 0.3, end: 1.0).animate(sizeController);
    delayedAnimation.addListener(() {
      scaleDoubles[i] = delayedAnimation.value;
      postInvalidate();
    });
    // size.
    controllers.add(sizeController);
  }
  return controllers;
}