setLeftIndex method
Implementation
void setLeftIndex(int index) {
DateTime time = currentTime.add(Duration(days: index));
if (isAtSameDay(minTime, time)) {
var index = min(24 - minTime!.hour - 1, _currentIndex[1]!);
this.setMiddleIndex(index);
} else if (isAtSameDay(maxTime, time)) {
var index = min(maxTime!.hour, _currentIndex[1]!);
this.setMiddleIndex(index);
}
}