poi/src/contrib/src/org/apache/poi/hssf/contrib/view/SVFractionalFormat.java

257 lines
8.1 KiB
Java

/*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache POI" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache POI", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.poi.hssf.contrib.view;
import java.text.*;
/**
* This class is used to format cells into their fractional format.
*
* I cant be 100% sure that the same fractional value will be displayed as in
* excel but then again it is a lossy formating mode anyway
*
* @author Jason Height
* @created 15 July 2002
*/
public class SVFractionalFormat extends Format {
private short ONE_DIGIT = 1;
private short TWO_DIGIT = 2;
private short THREE_DIGIT = 3;
private short UNITS = 4;
private int units = 1;
private short mode = -1;
/** Constructs a new FractionalFormatter
*
* The formatStr defines how the number will be formatted
* # ?/? Up to one digit
* # ??/?? Up to two digits
* # ???/??? Up to three digits
* # ?/2 In halves
* # ?/4 In quarters
* # ?/8 In eighths
* # ?/16 In sixteenths
* # ?/10 In tenths
* # ?/100 In hundredths
*/
public SVFractionalFormat(String formatStr) {
if ("# ?/?".equals(formatStr))
mode = ONE_DIGIT;
else if ("# ??/??".equals(formatStr))
mode = TWO_DIGIT;
else if ("# ???/???".equals(formatStr))
mode = THREE_DIGIT;
else if ("# ?/2".equals(formatStr)) {
mode = UNITS;
units = 2;
} else if ("# ?/4".equals(formatStr)) {
mode = UNITS;
units = 4;
} else if ("# ?/8".equals(formatStr)) {
mode = UNITS;
units = 8;
} else if ("# ?/16".equals(formatStr)) {
mode = UNITS;
units = 16;
} else if ("# ?/10".equals(formatStr)) {
mode = UNITS;
units = 10;
} else if ("# ?/100".equals(formatStr)) {
mode = UNITS;
units = 100;
}
}
/**
* Returns a fractional string representation of a double to a maximum denominator size
*
* This code has been translated to java from the following web page.
* http://www.codeproject.com/cpp/fraction.asp
* Originally coded in c++ By Dean Wyant dwyant@mindspring.com
* The code on the web page is freely available.
*
* @param f Description of the Parameter
* @param MaxDen Description of the Parameter
* @return Description of the Return Value
*/
private String format(final double f, final int MaxDen) {
long Whole = (long)f;
int sign = 1;
if (f < 0) {
sign = -1;
}
double Precision = 0.00001;
double AllowedError = Precision;
double d = Math.abs(f);
d -= Whole;
double Frac = d;
double Diff = Frac;
long Num = 1;
long Den = 0;
long A = 0;
long B = 0;
long i = 0;
if (Frac > Precision) {
while (true) {
d = 1.0 / d;
i = (long) (d + Precision);
d -= i;
if (A > 0) {
Num = i * Num + B;
}
Den = (long) (Num / Frac + 0.5);
Diff = Math.abs((double) Num / Den - Frac);
if (Den > MaxDen) {
if (A > 0) {
Num = A;
Den = (long) (Num / Frac + 0.5);
Diff = Math.abs((double) Num / Den - Frac);
} else {
Den = MaxDen;
Num = 1;
Diff = Math.abs((double) Num / Den - Frac);
if (Diff > Frac) {
Num = 0;
Den = 1;
// Keeps final check below from adding 1 and keeps Den from being 0
Diff = Frac;
}
}
break;
}
if ((Diff <= AllowedError) || (d < Precision)) {
break;
}
Precision = AllowedError / Diff;
// This calcualtion of Precision does not always provide results within
// Allowed Error. It compensates for loss of significant digits that occurs.
// It helps to round the inprecise reciprocal values to i.
B = A;
A = Num;
}
}
if (Num == Den) {
Whole++;
Num = 0;
Den = 0;
} else if (Den == 0) {
Num = 0;
}
if (sign < 0) {
if (Whole == 0) {
Num = -Num;
} else {
Whole = -Whole;
}
}
return new StringBuffer().append(Whole).append(" ").append(Num).append("/").append(Den).toString();
}
/** This method formats the double in the units specified.
* The usints could be any number but in this current implementation it is
* halves (2), quaters (4), eigths (8) etc
*/
private String formatUnit(double f, int units) {
long Whole = (long)f;
f -= Whole;
long Num = Math.round(f * units);
return new StringBuffer().append(Whole).append(" ").append(Num).append("/").append(units).toString();
}
public final String format(double val) {
if (mode == ONE_DIGIT) {
return format(val, 9);
} else if (mode == TWO_DIGIT) {
return format(val, 99);
} else if (mode == THREE_DIGIT) {
return format(val, 999);
} else if (mode == UNITS) {
return formatUnit(val , units);
}
throw new RuntimeException("Unexpected Case");
}
public StringBuffer format(Object obj,
StringBuffer toAppendTo,
FieldPosition pos) {
if (obj instanceof Number) {
toAppendTo.append(format(((Number)obj).doubleValue()));
return toAppendTo;
}
else throw new IllegalArgumentException("Can only handle Numbers");
}
public Object parseObject(String source,
ParsePosition status) {
//JMH TBD
return null;
}
public Object parseObject(String source)
throws ParseException {
//JMH TBD
return null;
}
public Object clone() {
//JMH TBD
return null;
}
}