To add animation in flutter, you need to follow these steps
1.Create variable using late AnimationController
2.Create initState function because widget needs to be generated again to activate animation
3.For AnimationController variable in initState(), need to create AnimationController() widget with vsync attribute
4.You can add duration, lowerbound and upperBound but these are optional
5.Use AnimatedBuilder(animation: ...) to show animation in application
6.In AnimationBuilder(), you need to pass builder attribute and in this attribute, you need to