def navigate(tp):
start = GregorianDateTime.from_time(curret_period.start_time)
end = GregorianDateTime.from_time(curret_period.end_time)
start_months = start.year * 12 + start.month
end_months = end.year * 12 + end.month
month_diff = end_months - start_months
month_delta = month_diff * direction
new_start_year, new_start_month = _months_to_year_and_month(
start_months + month_delta)
new_end_year, new_end_month = _months_to_year_and_month(end_months +
month_delta)
try:
new_start = start.replace(year=new_start_year,
month=new_start_month)
new_end = end.replace(year=new_end_year, month=new_end_month)
start = new_start.to_time()
end = new_end.to_time()
if end > GregorianTimeType().get_max_time():
raise ValueError()
if start < GregorianTimeType().get_min_time():
raise ValueError()
except ValueError:
if direction < 0:
raise TimeOutOfRangeLeftError()
else:
raise TimeOutOfRangeRightError()
return tp.update(start, end)
def navigate(tp):
year_delta = direction * _calculate_year_diff(curret_period)
gregorian_start = GregorianDateTime.from_time(curret_period.start_time)
gregorian_end = GregorianDateTime.from_time(curret_period.end_time)
new_start_year = gregorian_start.year + year_delta
new_end_year = gregorian_end.year + year_delta
try:
new_start = gregorian_start.replace(year=new_start_year).to_time()
new_end = gregorian_end.replace(year=new_end_year).to_time()
if new_end > GregorianTimeType().get_max_time():
raise ValueError()
if new_start < GregorianTimeType().get_min_time():
raise ValueError()
except ValueError:
if direction < 0:
raise TimeOutOfRangeLeftError()
else:
raise TimeOutOfRangeRightError()
return tp.update(new_start, new_end)