timeBench.action.layout.timescale.GregorianTimeUnit Maven / Gradle / Ivy
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package timeBench.action.layout.timescale;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import timeBench.util.DateUtil;
class GregorianTimeUnit extends TimeUnit {
private long maxLengthInMillis;
private int field;
private int factor;
/**
* Creates an TimeUnit with factor 1.
*
* @param name
* the name of the TimeUnit
* @param field
* the {@link Calendar} field used to determine the
* maxLengthInMillis
* @param shortFormat
* the short {@link DateFormat}
* @param longFormat
* the long {@link DateFormat}
* @param fullFormat
* the full {@link DateFormat}
*/
public GregorianTimeUnit(String name, int field, DateFormat shortFormat, DateFormat longFormat, DateFormat fullFormat) {
this(name, field, 1, shortFormat, longFormat, fullFormat);
}
/**
*
* Creates a new TimeUnit with a given name, a {@link Calendar} field, the
* factor to multiply the milliseconds representing the {@link Calendar}
* field with, and the various {@link DateFormat}s, {@link Date}s with
* this TimeUnit should be formatted with.
*
*
* The maxLengthInMillis of this TimeUnit it calculated upon the given
* {@link Calendar} field and the factor. For example, if the
* {@link Calendar} field is Calendar.SECOND and the factor is 5, the
* maxLengthInMillis of the TimeUnit will be 5000. The name therefore should
* be "5 Seconds", the shortFormat could be "ss", the longformat "HH:mm:ss"
* and the fullFormat "dd.MM yyyy HH:mm:ss.SSS".
*
*
* The field param is furthermore used to calculate dates fitting into this
* TimeUnit, as this is not always as straightforward as finding a multiple
* of maxLengthInMillis. As an accuracy like "Months" has different lengths,
* depending on the date, it's not enough just to define a length. Thus you
* have to provide field and a factor and the TimeUnit does the hard work
* for you like finding dates 'fitting' into this TimeUnit (see
* {@link TimeUnit#next(long)} and {@link TimeUnit#previous(long)}).
*
*
* Dates either fit or don't fit into a TimeUnit. A date that fits into a
* TimeUnit is like a number that has a common divider with another number.
* For example a TimeUnit "5 Seconds" has the length 5000, which means that
* every 5th second fits into this TimeUnit, like any day with time 7:05:05
* but not 7:05:06. Another example is "Months", where 01-03-07 00:00:00
* would fit into this TimeUnit while 01/03/07 00:01:00 would not. The next
* fitting date would be 01/04/07 00:00:00.
*
*
* @param name
* the name of the TimeUnit
* @param field
* the {@link Calendar} field used to determine the
* maxLengthInMillis
* @param factor
* the factor the milliseconds representing the {@link Calendar}
* field should be multiplied with to calculate the
* maxLengthInMillis
* @param shortFormat
* the short {@link DateFormat}
* @param longFormat
* the long {@link DateFormat}
* @param fullFormat
* the full {@link DateFormat}
*/
public GregorianTimeUnit(String name, int field, int factor, DateFormat shortFormat, DateFormat longFormat,
DateFormat fullFormat) {
super(name, shortFormat, longFormat, fullFormat);
this.field = field;
this.factor = factor;
maxLengthInMillis = getMaxLength(field, factor);
}
@Override
public long getMaxLengthInMillis() {
return maxLengthInMillis;
}
@Override
public long previous(long date) {
return DateUtil.truncate(date, field, factor);
}
@Override
public long next(long date) {
long defaultNext = date + getMaxLengthInMillis();
long adjusted = previous(defaultNext);
if (adjusted > date) {
return adjusted;
} else {
return defaultNext;
}
}
/**
* Returns the maximum length of a given {@link Calendar} field and a
* multiplying factor in milliseconds.
*
* @param field
* the {@link Calendar} field
* @param factor
* the factor the milliseconds representing the {@link Calendar}
* field should be multiplied with to calculate the
* maxLengthInMillis
* @return the maximum length in milliseconds
*/
public static long getMaxLength(int field, int factor) {
long maxLength = (long) factor;
switch (field) {
case Calendar.MONTH:
maxLength *= 31;
case Calendar.DAY_OF_MONTH:
maxLength *= 25;
case Calendar.HOUR:
maxLength *= 60;
case Calendar.MINUTE:
maxLength *= 60;
case Calendar.SECOND:
maxLength *= 1000;
case Calendar.MILLISECOND:
break;
case Calendar.WEEK_OF_YEAR:
maxLength = (long) 1000l * 60 * 60 * 25 * 7 * factor;
break;
case Calendar.YEAR:
maxLength = (long) 1000l * 60 * 60 * 24 * 366 * factor;
break;
default:
throw new IllegalArgumentException("unsupported field");
}
return maxLength;
}
}