/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2012, by Object Refinery Limited 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.]
*
* ---------------------------
* StandardTickUnitSource.java
* ---------------------------
* (C) Copyright 2003-2008, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 23-Sep-2003 : Version 1 (DG);
* 25-Oct-2007 : Implemented Serializable and equals() method (DG);
*
*/
package org.jfree.chart.axis;
import java.io.Serializable;
import java.text.DecimalFormat;
/**
* A source that can used by the {@link NumberAxis} class to obtain a
* suitable {@link TickUnit}. Instances of this class are {@link Serializable}
* from version 1.0.7 onwards. Cloning is not supported, because instances
* are immutable.
*/
public class StandardTickUnitSource implements TickUnitSource, Serializable {
/** Constant for log(10.0). */
private static final double LOG_10_VALUE = Math.log(10.0);
/**
* Default constructor.
*/
public StandardTickUnitSource() {
super();
}
/**
* Returns a tick unit that is larger than the supplied unit.
*
* @param unit the unit (<code>null</code> not permitted).
*
* @return A tick unit that is larger than the supplied unit.
*/
@Override
public TickUnit getLargerTickUnit(TickUnit unit) {
double x = unit.getSize();
double log = Math.log(x) / LOG_10_VALUE;
double higher = Math.ceil(log);
return new NumberTickUnit(Math.pow(10, higher),
new DecimalFormat("0.0E0"));
}
/**
* Returns the tick unit in the collection that is greater than or equal
* to (in size) the specified unit.
*
* @param unit the unit (<code>null</code> not permitted).
*
* @return A unit from the collection.
*/
@Override
public TickUnit getCeilingTickUnit(TickUnit unit) {
return getLargerTickUnit(unit);
}
/**
* Returns the tick unit in the collection that is greater than or equal
* to the specified size.
*
* @param size the size.
*
* @return A unit from the collection.
*/
@Override
public TickUnit getCeilingTickUnit(double size) {
double log = Math.log(size) / LOG_10_VALUE;
double higher = Math.ceil(log);
return new NumberTickUnit(Math.pow(10, higher),
new DecimalFormat("0.0E0"));
}
/**
* Tests this instance for equality with an arbitrary object.
*
* @param obj the object (<code>null</code> permitted).
*
* @return A boolean.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
return (obj instanceof StandardTickUnitSource);
}
/**
* Returns a hash code for this instance.
*
* @return A hash code.
*/
@Override
public int hashCode() {
return 0;
}
}