calcPrecedingScrollExtent method
double?
calcPrecedingScrollExtent({
- required GlobalKey<
State< nestedScrollViewKey,StatefulWidget> > - required BuildContext sliverContext,
Implementation
double? calcPrecedingScrollExtent({
required GlobalKey nestedScrollViewKey,
required BuildContext sliverContext,
}) {
double precedingScrollExtent = 0;
var _obj = ObserverUtils.findRenderObject(sliverContext);
if (_obj is! RenderSliverMultiBoxAdaptor) return null;
precedingScrollExtent = _obj.constraints.precedingScrollExtent;
// Get SliverFillRemaining
final remainingSliverContext = fetchRemainingSliverContext(
nestedScrollViewKey: nestedScrollViewKey,
);
if (remainingSliverContext == null || remainingSliverRenderObj == null) {
return null;
}
precedingScrollExtent +=
remainingSliverRenderObj?.constraints.precedingScrollExtent ?? 0;
return precedingScrollExtent;
}