public DateIntervalType calculateIntervalSize(
Date minDate, Date maxDate, ColumnGroup columnGroup) {
DateIntervalType intervalType = DateIntervalType.getByName(columnGroup.getIntervalSize());
if (intervalType == null) {
intervalType = YEAR;
}
if (minDate == null || maxDate == null) {
return intervalType;
}
long millis = (maxDate.getTime() - minDate.getTime());
if (millis <= 0) {
return intervalType;
}
// Calculate the interval type used according to the constraints set.
int maxIntervals = columnGroup.getMaxIntervals();
if (maxIntervals < 1) maxIntervals = 15;
for (DateIntervalType type : values()) {
long nintervals = millis / getDurationInMillis(type);
if (nintervals < maxIntervals) {
intervalType = type;
break;
}
}
// Ensure the interval mode obtained is always greater or equals than the preferred interval
// size.
DateIntervalType intervalSize = null;
if (!StringUtils.isBlank(columnGroup.getIntervalSize())) {
intervalSize = getByName(columnGroup.getIntervalSize());
}
if (intervalSize != null && compare(intervalType, intervalSize) == -1) {
intervalType = intervalSize;
}
return intervalType;
}
public IntervalList build(DataSetHandler handler, ColumnGroup columnGroup) {
IntervalDateRangeList results = new IntervalDateRangeList(columnGroup);
DataSet dataSet = handler.getDataSet();
List values = dataSet.getColumnById(columnGroup.getSourceId()).getValues();
if (values.isEmpty()) {
return results;
}
// Sort the column dates.
DataSetSort sortOp = new DataSetSort();
sortOp.addSortColumn(new ColumnSort(columnGroup.getSourceId(), SortOrder.ASCENDING));
DataSetHandler sortResults = handler.sort(sortOp);
List<Integer> sortedRows = sortResults.getRows();
if (sortedRows == null || sortedRows.isEmpty()) {
return results;
}
// Get the lower & upper limits (discard nulls).
SortedList sortedValues = new SortedList(values, sortedRows);
Date minDate = null;
Date maxDate = null;
for (int i = 0; minDate == null && i < sortedValues.size(); i++) {
minDate = (Date) sortedValues.get(i);
}
for (int i = sortedValues.size() - 1; maxDate == null && i >= 0; i--) {
maxDate = (Date) sortedValues.get(i);
}
// If min/max are equals then return a single interval.
DateIntervalType intervalType = calculateIntervalSize(minDate, maxDate, columnGroup);
if (minDate == null || minDate.compareTo(maxDate) == 0) {
IntervalDateRange interval = new IntervalDateRange(0, intervalType, minDate, maxDate);
for (int row = 0; row < sortedValues.size(); row++) interval.getRows().add(row);
results.add(interval);
results.setIntervalType(columnGroup.getIntervalSize());
results.setMinValue(minDate);
results.setMaxValue(maxDate);
return results;
}
// Create the intervals according to the min/max dates.
Calendar c = firstIntervalDate(intervalType, minDate, columnGroup);
int index = 0;
int counter = 0;
while (c.getTime().compareTo(maxDate) <= 0) {
Date intervalMinDate = c.getTime();
// Create the next interval
nextIntervalDate(c, intervalType, 1);
Date intervalMaxDate = c.getTime();
IntervalDateRange interval =
new IntervalDateRange(counter++, intervalType, intervalMinDate, intervalMaxDate);
results.add(interval);
// Add the target rows
boolean stop = false;
while (!stop) {
if (index >= sortedValues.size()) {
stop = true;
} else {
Date dateValue = (Date) sortedValues.get(index);
Integer row = sortedRows.get(index);
if (dateValue == null) {
index++;
} else if (dateValue.before(intervalMaxDate)) {
interval.getRows().add(row);
index++;
} else {
stop = true;
}
}
}
}
// Reverse intervals if requested
boolean asc = columnGroup.isAscendingOrder();
if (!asc) Collections.reverse(results);
// Return the results
results.setIntervalType(intervalType.toString());
results.setMinValue(minDate);
results.setMaxValue(maxDate);
return results;
}