anim

Describe the Anim

Animation

AnimValues(
 name:"animationName", 
 values: [value0, value1, value2, ...],
 duration: Duration(seconds: 1),
);

Animation schedulers

AnimSequentially(anims: [
 anim1, anim2, anim3
]);
AnimTogether(anims: [
 anim1, anim2, anim3
]);

Example

this.anim = Anim(
 vsync: this,
 listener: () {
 setState(() {
 /* rebuild */
 });
 },
 /* Define initial values, used when the animation has not been launched */
 initiaValues: {
 "alpha": 1,
 "size": 100,
 },
 animations: [
 AnimSequentially(
 startDelay: const Duration(milliseconds: 400),
 anims: [
 //Animate the alpha, then the size
 AnimValues(
 name: "alpha",
 curve: Curves.easeIn,
 duration: const Duration(milliseconds: 800),
 values: [1, 0.4, 0.8, 0.5],
 ),
 AnimValues(
 name: "size",
 curve: Curves.easeIn,
 duration: const Duration(milliseconds: 800),
 values: [100, 140, 80],
 ),
 //and finally animate those two values together
 AnimTogether(anims: [
 AnimValues(
 name: "alpha",
 curve: Curves.easeIn,
 duration: const Duration(milliseconds: 800),
 values: [0.5, 1],
 ),
 AnimValues(
 name: "size",
 curve: Curves.easeIn,
 duration: const Duration(milliseconds: 800),
 values: [80, 100],
 ),
 ])
 ]),
 ]);

Bind your Anim

@override
Widget build(BuildContext context) {
 return Opacity(
 opacity: this.anim["alpha"],
 child: SizedBox(
 height: this.anim["size"],
 width: this.anim["size"]
 child: _yourView(),
 ),
 );
 }
}

Flutter