update method Null safety
- DragUpdateDetails details
override
The pointer has moved.
Implementation
@override
void update(DragUpdateDetails details) {
assert(details.primaryDelta != null);
_lastDetails = details;
double offset = details.primaryDelta!;
if (offset != 0.0) {
_lastNonStationaryTimestamp = details.sourceTimeStamp;
}
// By default, iOS platforms carries momentum and has a start threshold
// (configured in [BouncingScrollPhysics]). The 2 operations below are
// no-ops on Android.
_maybeLoseMomentum(offset, details.sourceTimeStamp);
offset = _adjustForScrollStartThreshold(offset, details.sourceTimeStamp);
if (offset == 0.0) {
return;
}
if (_reversed) {
offset = -offset;
}
delegate.applyUserOffset(offset);
}