Notes

AnimationController offers these methods to control the animation (and many others; see the documentation):

• forward(): animation goes from the current value to upperBound (default: 1.0)
• reverse(): animation goes from the current value to lowerBound (default: 0.0)
• repeat(): animation repeats forever
• stop(): stop the animation

Along with these methods to register listeners:

• addListener(): called every time the animation value changes (don't forget to call removeListener() in dispose())
• addStatusListener(): called when the animation status changes (don't forget to call removeStatusListener() in dispose())

To rebuild a widget when the animation value changes, use AnimatedBuilder.

AnimatedBuilder takes an animation argument of type Animation<double>.

AnimationController extends Animation<double> so it can be passed as an argument to AnimatedBuilder.

Note: AnimatedBuilder takes an optional child argument. See this article for an in-depth explanation:

• Flutter: Why do TweenAnimationBuilder and AnimatedBuilder have a child argument?