update method

void update(
  1. double offset,
  2. double maxScrollExtent,
  3. ScrollController controller
)

Reports a strip's live metrics.

Kept at its original signature so existing callers and subclasses keep working; which strip is authoritative is supplied out of band by registerStrip instead of being inferred from whoever reported last.

Implementation

void update(
    double offset, double maxScrollExtent, ScrollController controller) {
  if (_disposed) return;
  _strips.putIfAbsent(controller, () => false);
  _electOwner();
  _publishFromOwner();
}