DateTickUnit.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2022, by David Gilbert and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* -----------------
* DateTickUnit.java
* -----------------
* (C) Copyright 2000-2022, by David Gilbert.
*
* Original Author: David Gilbert;
* Contributor(s): Chris Boek;
*
*/
package org.jfree.chart.axis;
import java.io.Serializable;
import java.text.DateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Objects;
import java.util.TimeZone;
import org.jfree.chart.internal.Args;
/**
* A tick unit for use by subclasses of {@link DateAxis}. Instances of this
* class are immutable.
*/
public class DateTickUnit extends TickUnit implements Serializable {
/** For serialization. */
private static final long serialVersionUID = -7289292157229621901L;
/**
* The units.
*/
private DateTickUnitType unitType;
/** The unit count. */
private int count;
/**
* The roll unit type.
*/
private DateTickUnitType rollUnitType;
/** The roll count. */
private int rollCount;
/** The date formatter. */
private DateFormat formatter;
/**
* Creates a new date tick unit.
*
* @param unitType the unit type ({@code null} not permitted).
* @param multiple the multiple (of the unit type, must be > 0).
*/
public DateTickUnit(DateTickUnitType unitType, int multiple) {
this(unitType, multiple, DateFormat.getDateInstance(DateFormat.SHORT));
}
/**
* Creates a new date tick unit.
*
* @param unitType the unit type ({@code null} not permitted).
* @param multiple the multiple (of the unit type, must be > 0).
* @param formatter the date formatter ({@code null} not permitted).
*/
public DateTickUnit(DateTickUnitType unitType, int multiple,
DateFormat formatter) {
this(unitType, multiple, unitType, multiple, formatter);
}
/**
* Creates a new unit.
*
* The {@code rollUnitType} and {@code rollCount} are intended to roll the date forward when it falls on a "hidden" part of the DateAxis. For example, if the tick size is 1 week (7 days), but Saturday and Sunday are hidden, if the ticks happen to fall on Saturday, none of them will be visible. A sensible {@code rollUnitType}/{@code rollCount} would be 1 day, so that the date would roll forward to the following Monday, which is visible.
*
* @param unitType the unit.
* @param multiple the multiple.
* @param rollUnitType the roll unit.
* @param rollMultiple the roll multiple.
* @param formatter the date formatter ({@code null} not permitted).
*/
public DateTickUnit(DateTickUnitType unitType, int multiple,
DateTickUnitType rollUnitType, int rollMultiple,
DateFormat formatter) {
super(DateTickUnit.getMillisecondCount(unitType, multiple));
Args.nullNotPermitted(formatter, "formatter");
if (multiple <= 0) {
throw new IllegalArgumentException("Requires 'multiple' > 0.");
}
if (rollMultiple <= 0) {
throw new IllegalArgumentException("Requires 'rollMultiple' > 0.");
}
this.unitType = unitType;
this.count = multiple;
this.rollUnitType = rollUnitType;
this.rollCount = rollMultiple;
this.formatter = formatter;
}
/**
* Returns the unit type.
*
* @return The unit type (never {@code null}).
*/
public DateTickUnitType getUnitType() {
return this.unitType;
}
/**
* Returns the unit multiple.
*
* @return The unit multiple (always > 0).
*/
public int getMultiple() {
return this.count;
}
/**
* Returns the roll unit type.
*
* @return The roll unit type (never {@code null}).
*/
public DateTickUnitType getRollUnitType() {
return this.rollUnitType;
}
/**
* Returns the roll unit multiple.
*
* @return The roll unit multiple.
*/
public int getRollMultiple() {
return this.rollCount;
}
/**
* Formats a value.
*
* @param milliseconds date in milliseconds since 01-01-1970.
*
* @return The formatted date.
*/
@Override
public String valueToString(double milliseconds) {
return this.formatter.format(new Date((long) milliseconds));
}
/**
* Formats a date using the tick unit's formatter.
*
* @param date the date.
*
* @return The formatted date.
*/
public String dateToString(Date date) {
return this.formatter.format(date);
}
/**
* Calculates a new date by adding this unit to the base date.
*
* @param base the base date.
* @param zone the time zone for the date calculation.
*
* @return A new date one unit after the base date.
*/
public Date addToDate(Date base, TimeZone zone) {
// as far as I know, the Locale for the calendar only affects week
// number calculations, and since DateTickUnit doesn't do week
// arithmetic, the default locale (whatever it is) should be fine
// here...
Calendar calendar = Calendar.getInstance(zone);
calendar.setTime(base);
calendar.add(this.unitType.getCalendarField(), this.count);
return calendar.getTime();
}
/**
* Rolls the date forward by the amount specified by the roll unit and
* count.
*
* @param base the base date.
* @return The rolled date.
*
* @see #rollDate(Date, TimeZone)
*/
public Date rollDate(Date base) {
return rollDate(base, TimeZone.getDefault());
}
/**
* Rolls the date forward by the amount specified by the roll unit and
* count.
*
* @param base the base date.
* @param zone the time zone.
*
* @return The rolled date.
*/
public Date rollDate(Date base, TimeZone zone) {
// as far as I know, the Locale for the calendar only affects week
// number calculations, and since DateTickUnit doesn't do week
// arithmetic, the default locale (whatever it is) should be fine
// here...
Calendar calendar = Calendar.getInstance(zone);
calendar.setTime(base);
calendar.add(this.rollUnitType.getCalendarField(), this.rollCount);
return calendar.getTime();
}
/**
* Returns a field code that can be used with the {@code Calendar}
* class.
*
* @return The field code.
*/
public int getCalendarField() {
return this.unitType.getCalendarField();
}
/**
* Returns the (approximate) number of milliseconds for the given unit and
* unit count.
* <P>
* This value is an approximation some of the time (e.g. months are
* assumed to have 31 days) but this shouldn't matter.
*
* @param unit the unit.
* @param count the unit count.
*
* @return The number of milliseconds.
*/
private static long getMillisecondCount(DateTickUnitType unit, int count) {
if (unit.equals(DateTickUnitType.YEAR)) {
return (365L * 24L * 60L * 60L * 1000L) * count;
}
else if (unit.equals(DateTickUnitType.MONTH)) {
return (31L * 24L * 60L * 60L * 1000L) * count;
}
else if (unit.equals(DateTickUnitType.DAY)) {
return (24L * 60L * 60L * 1000L) * count;
}
else if (unit.equals(DateTickUnitType.HOUR)) {
return (60L * 60L * 1000L) * count;
}
else if (unit.equals(DateTickUnitType.MINUTE)) {
return (60L * 1000L) * count;
}
else if (unit.equals(DateTickUnitType.SECOND)) {
return 1000L * count;
}
else if (unit.equals(DateTickUnitType.MILLISECOND)) {
return count;
}
else {
throw new IllegalArgumentException("The 'unit' argument has a "
+ "value that is not recognised.");
}
}
/**
* Tests this unit for equality with another object.
*
* @param obj the object ({@code null} permitted).
*
* @return {@code true} or {@code false}.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof DateTickUnit)) {
return false;
}
if (!super.equals(obj)) {
return false;
}
DateTickUnit that = (DateTickUnit) obj;
if (!(this.unitType.equals(that.unitType))) {
return false;
}
if (this.count != that.count) {
return false;
}
if (!Objects.equals(this.formatter, that.formatter)) {
return false;
}
return true;
}
/**
* Returns a hash code for this object.
*
* @return A hash code.
*/
@Override
public int hashCode() {
int result = 19;
result = 37 * result + this.unitType.hashCode();
result = 37 * result + this.count;
result = 37 * result + this.formatter.hashCode();
return result;
}
/**
* Returns a string representation of this instance, primarily used for
* debugging purposes.
*
* @return A string representation of this instance.
*/
@Override
public String toString() {
return "DateTickUnit[" + this.unitType.toString() + ", "
+ this.count + "]";
}
}