/* ===========================================================
 
* JFreeChart : a free chart library for the Java(tm) platform
 
* ===========================================================
 
*
 
* (C) Copyright 2000-2016, 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} 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} 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} 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;
    
}

}