purgeActive method
void
purgeActive()
Capacity-preserving purge of every active slide: entries cleared and the ticker STOPPED, not disposed, so the next install restarts it.
The controller calls this on the style transition meaning "stop
slide motion now", which is reorderSlide being zeroed. That is the
other half of the disabled-mode split: a zero family refuses NEW
motion at install time, while stopping EXISTING motion is this
explicit event. Unlike clearAll this is safe mid-lifecycle, since
_slideByNid keeps its capacity and later installs cannot
range-error.
Implementation
void purgeActive() {
if (hasActive) {
_clearAllSlidesInternal();
}
_ticker?.stop();
}