maybeStartSnapAnimation method Null safety
- ScrollDirection direction
If the header isn't already fully exposed, then scroll it into view.
Implementation
void maybeStartSnapAnimation(ScrollDirection direction) {
final FloatingHeaderSnapConfiguration? snap = snapConfiguration;
if (snap == null)
return;
if (direction == ScrollDirection.forward && _effectiveScrollOffset! <= 0.0)
return;
if (direction == ScrollDirection.reverse && _effectiveScrollOffset! >= maxExtent)
return;
_updateAnimation(
snap.duration,
direction == ScrollDirection.forward ? 0.0 : maxExtent,
snap.curve,
);
_controller?.forward(from: 0.0);
}