/**
* Returns the the next date of this recurrence given a seed date and start date. The seed date
* indicates the start of the fist occurrence of this recurrence. The start date is the starting
* date to search for the next recurrence. Return null if there is no occurrence date after start
* date.
*
* @return the next date in the recurrence series after startDate
* @param seed the start date of this Recurrence's first instance
* @param startDate the date to start the search
*/
public final Date getNextDate(final Date seed, final Date startDate) {
final Calendar cal = Dates.getCalendarInstance(seed);
cal.setTime(seed);
// optimize the start time for selecting candidates
// (only applicable where a COUNT is not specified)
if (getCount() < 1) {
final Calendar seededCal = (Calendar) cal.clone();
while (seededCal.getTime().before(startDate)) {
cal.setTime(seededCal.getTime());
increment(seededCal);
}
}
int invalidCandidateCount = 0;
int noCandidateIncrementCount = 0;
Date candidate = null;
final Value value = seed instanceof DateTime ? Value.DATE_TIME : Value.DATE;
while (true) {
final Date candidateSeed = Dates.getInstance(cal.getTime(), value);
if (getUntil() != null && candidate != null && candidate.after(getUntil())) {
break;
}
if (getCount() > 0 && invalidCandidateCount >= getCount()) {
break;
}
if (Value.DATE_TIME.equals(value)) {
if (((DateTime) seed).isUtc()) {
((DateTime) candidateSeed).setUtc(true);
} else {
((DateTime) candidateSeed).setTimeZone(((DateTime) seed).getTimeZone());
}
}
final DateList candidates = getCandidates(candidateSeed, value);
if (!candidates.isEmpty()) {
noCandidateIncrementCount = 0;
// sort candidates for identifying when UNTIL date is exceeded..
Collections.sort(candidates);
for (final Iterator<Date> i = candidates.iterator(); i.hasNext(); ) {
candidate = i.next();
// don't count candidates that occur before the seed date..
if (!candidate.before(seed)) {
// Candidate must be after startDate because
// we want the NEXT occurrence
if (!candidate.after(startDate)) {
invalidCandidateCount++;
} else if (getCount() > 0 && invalidCandidateCount >= getCount()) {
break;
} else if (!(getUntil() != null && candidate.after(getUntil()))) {
return candidate;
}
}
}
} else {
noCandidateIncrementCount++;
if ((maxIncrementCount > 0) && (noCandidateIncrementCount > maxIncrementCount)) {
break;
}
}
increment(cal);
}
return null;
}
/**
* Returns a list of start dates in the specified period represented by this recur. This method
* includes a base date argument, which indicates the start of the fist occurrence of this
* recurrence. The base date is used to inject default values to return a set of dates in the
* correct format. For example, if the search start date (start) is Wed, Mar 23, 12:19PM, but the
* recurrence is Mon - Fri, 9:00AM - 5:00PM, the start dates returned should all be at 9:00AM, and
* not 12:19PM.
*
* @return a list of dates represented by this recur instance
* @param seed the start date of this Recurrence's first instance
* @param periodStart the start of the period
* @param periodEnd the end of the period
* @param value the type of dates to generate (i.e. date/date-time)
* @param maxCount limits the number of instances returned. Up to one years worth extra may be
* returned. Less than 0 means no limit
*/
public final DateList getDates(
final Date seed,
final Date periodStart,
final Date periodEnd,
final Value value,
final int maxCount) {
final DateList dates = new DateList(value);
if (seed instanceof DateTime) {
if (((DateTime) seed).isUtc()) {
dates.setUtc(true);
} else {
dates.setTimeZone(((DateTime) seed).getTimeZone());
}
}
final Calendar cal = Dates.getCalendarInstance(seed);
cal.setTime(seed);
// optimize the start time for selecting candidates
// (only applicable where a COUNT is not specified)
if (getCount() < 1) {
final Calendar seededCal = (Calendar) cal.clone();
while (seededCal.getTime().before(periodStart)) {
cal.setTime(seededCal.getTime());
increment(seededCal);
}
}
int invalidCandidateCount = 0;
int noCandidateIncrementCount = 0;
Date candidate = null;
while ((maxCount < 0) || (dates.size() < maxCount)) {
final Date candidateSeed = Dates.getInstance(cal.getTime(), value);
if (getUntil() != null && candidate != null && candidate.after(getUntil())) {
break;
}
if (periodEnd != null && candidate != null && candidate.after(periodEnd)) {
break;
}
if (getCount() >= 1 && (dates.size() + invalidCandidateCount) >= getCount()) {
break;
}
// if (Value.DATE_TIME.equals(value)) {
if (candidateSeed instanceof DateTime) {
if (dates.isUtc()) {
((DateTime) candidateSeed).setUtc(true);
} else {
((DateTime) candidateSeed).setTimeZone(dates.getTimeZone());
}
}
final DateList candidates = getCandidates(candidateSeed, value);
if (!candidates.isEmpty()) {
noCandidateIncrementCount = 0;
// sort candidates for identifying when UNTIL date is exceeded..
Collections.sort(candidates);
for (final Iterator<Date> i = candidates.iterator(); i.hasNext(); ) {
candidate = i.next();
// don't count candidates that occur before the seed date..
if (!candidate.before(seed)) {
// candidates exclusive of periodEnd..
if (candidate.before(periodStart) || !candidate.before(periodEnd)) {
invalidCandidateCount++;
} else if (getCount() >= 1 && (dates.size() + invalidCandidateCount) >= getCount()) {
break;
} else if (!(getUntil() != null && candidate.after(getUntil()))) {
dates.add(candidate);
}
}
}
} else {
noCandidateIncrementCount++;
if ((maxIncrementCount > 0) && (noCandidateIncrementCount > maxIncrementCount)) {
break;
}
}
increment(cal);
}
// sort final list..
Collections.sort(dates);
return dates;
}
