/**
* Updates tick label for date axis.
*
* @param length the length of axis
*/
private void updateTickLabelForDateAxis(int length) {
double min = axis.getRange().lower;
double max = axis.getRange().upper;
double gridStepHint = Math.abs(max - min) / length * axis.getTick().getTickMarkStepHint();
timeUnit = getTimeUnit(gridStepHint);
if (timeUnit == Calendar.MILLISECOND
|| timeUnit == Calendar.SECOND
|| timeUnit == Calendar.MINUTE
|| timeUnit == Calendar.HOUR_OF_DAY
|| timeUnit == Calendar.DATE) {
Integer[] steps = possibleTickSteps.get(timeUnit);
for (int i = 0; i < steps.length - 1; i++) {
if (gridStepHint
< (getPeriodInMillis(timeUnit, steps[i]) + getPeriodInMillis(timeUnit, steps[i + 1]))
/ 2d) {
BigDecimal gridStep =
new BigDecimal(Long.valueOf(getPeriodInMillis(timeUnit, steps[i])).toString());
updateTickLabelForLinearScale(length, gridStep);
break;
}
}
} else if (timeUnit == Calendar.MONTH || timeUnit == Calendar.YEAR) {
updateTickLabelForMonthOrYear(length, gridStepHint, timeUnit);
}
}
/**
* Updates the tick label for month or year. The month and year are handled differently from other
* units of time, since 1 month and 1 year can be different depending on which time to start
* counting.
*
* @param length the length of axis
* @param gridStepHint the grid step hint
* @param tickStepUnit the tick step unit of time
*/
private void updateTickLabelForMonthOrYear(int length, double gridStepHint, int tickStepUnit) {
double min = axis.getRange().lower;
double max = axis.getRange().upper;
// get initial position
Calendar cal = Calendar.getInstance();
cal.setTime(new Date((long) min));
int month = cal.get(Calendar.MONTH);
int year = cal.get(Calendar.YEAR);
if (tickStepUnit == Calendar.MONTH) {
if (month == Calendar.DECEMBER) {
year++;
month = Calendar.JANUARY;
} else {
month++;
}
} else if (tickStepUnit == Calendar.YEAR) {
month = Calendar.JANUARY;
year++;
}
// get tick step
Integer[] steps = possibleTickSteps.get(tickStepUnit);
int step = steps[steps.length - 1];
for (int i = 0; i < steps.length - 1; i++) {
if (gridStepHint
< (getPeriodInMillis(tickStepUnit, steps[i])
+ getPeriodInMillis(tickStepUnit, steps[i + 1]))
/ 2d) {
step = steps[i];
break;
}
}
// set tick labels
cal.clear();
cal.set(year, month, 1);
while (cal.getTimeInMillis() < max) {
tickLabelValues.add(Double.valueOf(cal.getTimeInMillis()));
tickLabels.add(format(cal.getTimeInMillis()));
int tickLabelPosition = (int) ((cal.getTimeInMillis() - min) / (max - min) * length);
tickLabelPositions.add(tickLabelPosition);
if (tickStepUnit == Calendar.MONTH) {
month += step;
if (month + step > Calendar.DECEMBER) {
year++;
month -= Calendar.DECEMBER + 1;
}
} else if (tickStepUnit == Calendar.YEAR) {
year += step;
}
cal.clear();
cal.set(year, month, 1);
}
}
/**
* Updates tick label for log scale.
*
* @param length the length of axis
*/
private void updateTickLabelForLogScale(int length) {
double min = axis.getRange().lower;
double max = axis.getRange().upper;
int digitMin = (int) Math.ceil(Math.log10(min));
int digitMax = (int) Math.ceil(Math.log10(max));
final BigDecimal MIN = new BigDecimal(new Double(min).toString());
BigDecimal tickStep = pow(10, digitMin - 1);
BigDecimal firstPosition;
if (MIN.remainder(tickStep).doubleValue() <= 0) {
firstPosition = MIN.subtract(MIN.remainder(tickStep));
} else {
firstPosition = MIN.subtract(MIN.remainder(tickStep)).add(tickStep);
}
for (int i = digitMin; i <= digitMax; i++) {
for (BigDecimal j = firstPosition;
j.doubleValue() <= pow(10, i).doubleValue();
j = j.add(tickStep)) {
if (j.doubleValue() > max) {
break;
}
if (axis.isDateEnabled()) {
Date date = new Date((long) j.doubleValue());
tickLabels.add(format(date));
} else {
tickLabels.add(format(j.doubleValue()));
}
tickLabelValues.add(j.doubleValue());
int tickLabelPosition =
(int)
((Math.log10(j.doubleValue()) - Math.log10(min))
/ (Math.log10(max) - Math.log10(min))
* length);
tickLabelPositions.add(tickLabelPosition);
}
tickStep = tickStep.multiply(pow(10, 1));
firstPosition = tickStep.add(pow(10, i));
}
}
/**
* Updates tick label for category axis.
*
* @param length the length of axis
*/
private void updateTickLabelForCategoryAxis(int length) {
String[] series = axis.getCategorySeries();
if (series == null) {
return;
}
int min = (int) axis.getRange().lower;
int max = (int) axis.getRange().upper;
int sizeOfTickLabels = (series.length < max - min + 1) ? series.length : max - min + 1;
int initialIndex = (min < 0) ? 0 : min;
for (int i = 0; i < sizeOfTickLabels; i++) {
tickLabels.add(series[i + initialIndex]);
int tickLabelPosition = (int) (length * (i + 0.5) / sizeOfTickLabels);
tickLabelPositions.add(tickLabelPosition);
}
}
/**
* Updates tick label for normal scale.
*
* @param length axis length (>0)
* @param tickStep the tick step
*/
private void updateTickLabelForLinearScale(int length, BigDecimal tickStep) {
double min = axis.getRange().lower;
double max = axis.getRange().upper;
final BigDecimal MIN = new BigDecimal(new Double(min).toString());
BigDecimal firstPosition;
/* if (min % tickStep <= 0) */
if (MIN.remainder(tickStep).doubleValue() <= 0) {
/* firstPosition = min - min % tickStep */
firstPosition = MIN.subtract(MIN.remainder(tickStep));
} else {
/* firstPosition = min - min % tickStep + tickStep */
firstPosition = MIN.subtract(MIN.remainder(tickStep)).add(tickStep);
}
// the unit time starts from 1:00
if (axis.isDateEnabled()) {
BigDecimal zeroOclock =
firstPosition.subtract(new BigDecimal(new Double(3600000).toString()));
if (MIN.compareTo(zeroOclock) == -1) {
firstPosition = zeroOclock;
}
}
for (BigDecimal b = firstPosition; b.doubleValue() <= max; b = b.add(tickStep)) {
if (axis.isDateEnabled()) {
Date date = new Date((long) b.doubleValue());
tickLabels.add(format(date));
} else {
tickLabels.add(format(b.doubleValue()));
}
tickLabelValues.add(b.doubleValue());
int tickLabelPosition = (int) ((b.doubleValue() - min) / (max - min) * length);
tickLabelPositions.add(tickLabelPosition);
}
}
/**
* Updates tick label for normal scale.
*
* @param length axis length (>0)
*/
private void updateTickLabelForLinearScale(int length) {
double min = axis.getRange().lower;
double max = axis.getRange().upper;
updateTickLabelForLinearScale(length, getGridStep(length, min, max));
}