/**
* @function GetRelativeTo
* @brief Computes the valid dates relative to the relativeDate parameter taking
* in account the delta parameter (-1 or 1). This function is called from the
* GetNext and GetPrevious functions inherited from MonthDataSource class.
* @param1 relativeDate DateTime represents the date taken in account for the
* computations involving the previous/next elements inside a looping selector
* @param2 delta int represents the delta for the calculus, -1 implies the computations
* for a previous date and 1 for a next date.
* @return DateTime object relative to the value given as param1 regarding param2
*/
protected override DateTime?GetRelativeTo(DateTime relativeDate, int delta)
{
Microsoft.Phone.Controls.Primitives.DateTimeWrapper currentDate = (Microsoft.Phone.Controls.Primitives.DateTimeWrapper) this.SelectedItem;
int currentYear = currentDate.DateTime.Year;
int monthsInYear = 12;
// If the currentYear has the same value as the MaxDate.Year then the number of months inside this year
// will be equal to the month number of the MaxDate.Year
if (currentYear == MaxDate.Year)
{
monthsInYear = MaxDate.Month;
}
// Computing the nextMonth, taking in acount the delta (-1 or 1)
int nextMonth = ((monthsInYear + relativeDate.Month - 1 + delta) % monthsInYear) + 1;
// If our month makes the return date to out of bounds (regarding the Min and Max Dates
// we return null instead of the new date; this will make the looping stop at this certain value
if (MaxDate.Year == currentYear &&
MaxDate.Year == MinDate.Year &&
(nextMonth < MinDate.Month || nextMonth > MaxDate.Month))
{
return(null);
}
// Compute the next day
int nextDay = Math.Min(relativeDate.Day, DateTime.DaysInMonth(relativeDate.Year, nextMonth));
// Return the newly calculated DateTime object
return(new DateTime(relativeDate.Year, nextMonth, nextDay, relativeDate.Hour, relativeDate.Minute, relativeDate.Second));
}
/**
* @function GetRelativeTo
* @brief Computes the valid dates relative to the relativeDate parameter taking
* in account the delta parameter (-1 or 1). This function is called from the
* GetNext and GetPrevious functions inherited from DayDataSource class.
* @param1 relativeDate DateTime represents the date taken in account for the
* computations involving the previous/next elements inside a looping selector
* @param2 delta int represents the delta for the calculus, -1 implies the computations
* for a previous date and 1 for a next date.
* @return DateTime object relative to the value given as param1 regarding param2
*/
protected override DateTime?GetRelativeTo(DateTime relativeDate, int delta)
{
Microsoft.Phone.Controls.Primitives.DateTimeWrapper currentDate = (Microsoft.Phone.Controls.Primitives.DateTimeWrapper) this.SelectedItem;
int currentMonth = currentDate.DateTime.Month;
int currentYear = currentDate.DateTime.Year;
// If the date that we try to compute will be larger than the max date.
if ((MaxDate.Day == relativeDate.Day) && (MaxDate.Month == currentMonth) &&
(MaxDate.Year == currentYear) && (delta > 0))
{
return(null);
}
// If the date we try to compute will be smaller than the min date.
if ((MinDate.Day == relativeDate.Day) && (MinDate.Month == currentMonth) &&
(MinDate.Year == currentYear) && (delta < 0))
{
return(null);
}
// Compute the days in month value.
int daysInMonth = DateTime.DaysInMonth(currentYear, currentMonth);
// Compute the next day value.
int nextDay = ((((daysInMonth + relativeDate.Day) - 1) + delta) % daysInMonth) + 1;
// The special case in which we have the max year / monthe equal with the min year / month and basically
// we have just a day range
if (MaxDate.Year == currentYear && MaxDate.Month == currentMonth &&
MaxDate.Year == MinDate.Year && MaxDate.Month == MinDate.Month &&
(nextDay < MinDate.Day || nextDay > MaxDate.Day))
{
return(null);
}
if ((MaxDate.Year == currentYear && MaxDate.Month == currentMonth && nextDay > MaxDate.Day) || (MinDate.Year == currentYear && MinDate.Month == currentMonth && nextDay < MinDate.Day))
{
return(null);
}
return(new DateTime(currentYear, currentMonth, nextDay, relativeDate.Hour, relativeDate.Minute, relativeDate.Second));
}
