stop method
void
stop()
Stops (or pauses) the time countdown.
If the CountdownTimer currently stopped, then calling stop does nothing.
Implementation
void stop() {
if (!_watch.isRunning || _callback == null) {
return;
}
_watch.stop();
final remaining = _duration.inMicroseconds - _watch.elapsedMicroseconds;
if (remaining <= 0) {
_handle();
return;
}
_timer.cancel();
}