animation method

@override List<AnimationController> animation()

Implementation

@override
List<AnimationController> animation() {
  List<AnimationController> controllers = [];
  AnimationController alphaController = new AnimationController(
      duration: const Duration(milliseconds: 1000), vsync: context);
  Animation<int> alpha =
      new IntTween(begin: 255, end: 0).animate(alphaController);
  alpha.addListener(() {
    mAlpha = alpha.value;
    postInvalidate();
  });
  // alpha.
  controllers.add(alphaController);

  AnimationController sizeController = new AnimationController(
      duration: const Duration(milliseconds: 1000), vsync: context);
  sizeController.addListener(() {
    mScale = sizeController.value;
  });
  // alpha.
  controllers.add(sizeController);

  return controllers;
}