shouldReclip method
Called whenever a new instance of the custom clipper delegate class is provided to the clip object, or any time that a new clip object is created with a new instance of the custom clipper delegate class (which amounts to the same thing, because the latter is implemented in terms of the former).
If the new instance represents different information than the old instance, then the method should return true, otherwise it should return false.
If the method returns false, then the getClip call might be optimized away.
It's possible that the getClip method will get called even if shouldReclip returns false or if the shouldReclip method is never called at all (e.g. if the box changes size).
Implementation
@override
bool shouldReclip(WaveClipper oldClipper) {
return animationValue != oldClipper.animationValue;
}