onMouseDown method
Implementation
void onMouseDown(int count) {
if (disabled) return;
add(count);
autoAddTimer?.cancel();
addStepTimer?.cancel();
addStepTimer = null;
autoAddTimer = Timer(Duration(milliseconds: 600), () {
autoAddTimer = null;
addStepTimer?.cancel();
addStepTimer =
Timer.periodic(Duration(milliseconds: 10), (_) => add(count));
});
}