AnimationController

The AnimationController is a special Animation
object that generates a new value whenever the hardware
is ready for a new frame. All explicit
animations require an AnimationController.

What is an AnimationController?

Whether the animation should progress forward or backward
through the range of values once triggered.

The amount(s) that an animation’s value changes between each frame.

The following sections demonstrate how to use
AnimationController by providing step-by-step instructions for
creating your first explicit animation with
AnimationController[] and by covering the
underlying concepts of AnimationController.

Create your first explicit animation with AnimationController

The following example begins with no animation code—it
consists of a Material app home screen containing a green ball shape.

PENDING: Insert DartPad here