/*
* JScience - Java(TM) Tools and Libraries for the Advancement of Sciences.
* Copyright (C) 2006 - JScience (http://jscience.org/)
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software is
* freely granted, provided that this notice is preserved.
*/
package org.jscience.physics.amount;
import java.io.IOException;
import java.text.ParseException;
import org.jscience.economics.money.Currency;
import org.jscience.economics.money.Money;
import javax.measure.unit.Unit;
import javax.measure.unit.UnitFormat;
import javolution.lang.MathLib;
import javolution.text.Text;
import javolution.text.TextBuilder;
import javolution.text.TextFormat;
import javolution.text.TypeFormat;
import javolution.context.LocalContext;
//@RETROWEAVER import javolution.text.Appendable;
/**
* This class provides the interface for formatting and parsing {@link
* Amount measures} instances. For example:[code]
* // Display measurements using unscaled units (e.g. base units or alternate units).
* AmountFormat.setInstance(new AmountFormat() { // Context local.
* public Appendable format(Amount m, Appendable a) throws IOException {
* Unit u = m.getUnit();
* if (u instanceof TransformedUnit)
* u = ((TransformedUnit)u).getParentUnit();
* return AmountFormat.getPlusMinusErrorInstance(2).format(m.to(u), a);
* }
* public Amount parse(CharSequence csq, Cursor c) {
* return AmountFormat.getPlusMinusErrorInstance(2).parse(csq, c);
* }
* });[/code]
*
*
* @author Jean-Marie Dautelle
* @version 3.0, February 21, 2006
*/
public abstract class AmountFormat extends TextFormat> {
/**
* Holds current format.
*/
private static final LocalContext.Reference CURRENT = new LocalContext.Reference(
new PlusMinusError(2));
/**
* Default constructor.
*/
protected AmountFormat() {
}
/**
* Returns the current {@link javolution.context.LocalContext local}
* format (default AmountFormat.getPlusMinusErrorInstance(2)).
*
* @return the context local format.
* @see #getPlusMinusErrorInstance(int)
*/
public static AmountFormat getInstance() {
return CURRENT.get();
}
/**
* Sets the current {@link javolution.context.LocalContext local} format.
*
* @param format the new format.
*/
public static void setInstance(AmountFormat format) {
CURRENT.set(format);
}
/**
* Returns a format for which the error (if present) is stated using
* the '±' character; for example "(1.34 ± 0.01) m".
* This format can be used for formatting as well as for parsing.
*
* @param digitsInError the maximum number of digits in error.
*/
public static AmountFormat getPlusMinusErrorInstance(int digitsInError) {
return new PlusMinusError(digitsInError);
}
/**
* Returns a format for which the error is represented by an integer
* value in brackets; for example "1.3456[20] m"
* is equivalent to "1.3456 ± 0.0020 m".
* This format can be used for formatting as well as for parsing.
*
* @param digitsInError the maximum number of digits in error.
*/
public static AmountFormat getBracketErrorInstance(int digitsInError) {
return new BracketError(digitsInError);
}
/**
* Returns a format for which only digits guaranteed to be exact are
* written out. In other words, the error is always on the
* last digit and less than the last digit weight. For example,
* "1.34 m" means a length between 1.32 m and
* 1.35 m. This format can be used for formatting only.
*/
public static AmountFormat getExactDigitsInstance() {
return new ExactDigitsOnly();
}
/**
* This class represents the plus minus error format.
*/
private static class PlusMinusError extends AmountFormat {
/**
* Holds the number of digits in error.
*/
private int _errorDigits;
/**
* Creates a plus-minus error format having the specified
* number of digits in error.
*
* @param errorDigits the number of digits in error.
*/
private PlusMinusError(int errorDigits) {
_errorDigits = errorDigits;
}
@SuppressWarnings("unchecked")
@Override
public Appendable format(Amount arg0, Appendable arg1)
throws IOException {
if (arg0.getUnit() instanceof Currency)
return formatMoney(arg0, arg1);
if (arg0.isExact()) {
TypeFormat.format(arg0.getExactValue(), arg1);
arg1.append(' ');
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
double value = arg0.getEstimatedValue();
double error = arg0.getAbsoluteError();
int log10Value = (int) MathLib.floor(MathLib.log10(MathLib
.abs(value)));
int log10Error = (int) MathLib.floor(MathLib.log10(error));
int digits = log10Value - log10Error - 1; // Exact digits.
digits = MathLib.max(1, digits + _errorDigits);
boolean scientific = (MathLib.abs(value) >= 1E6)
|| (MathLib.abs(value) < 1E-6);
boolean showZeros = false;
arg1.append('(');
TypeFormat.format(value, digits, scientific, showZeros, arg1);
arg1.append(" ± ");
scientific = (MathLib.abs(error) >= 1E6)
|| (MathLib.abs(error) < 1E-6);
showZeros = true;
TypeFormat.format(error, _errorDigits, scientific, showZeros, arg1);
arg1.append(") ");
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
@Override
public Amount parse(CharSequence arg0, Cursor arg1) {
int start = arg1.getIndex();
try {
arg1.skip('(', arg0);
long value = TypeFormat.parseLong(arg0, 10, arg1);
if (arg0.charAt(arg1.getIndex()) == ' ') { // Exact!
arg1.skip(' ', arg0);
Unit unit = UnitFormat.getInstance().parseProductUnit(
arg0, arg1);
return Amount.valueOf(value, unit);
}
arg1.setIndex(start);
double amount = TypeFormat.parseDouble(arg0, arg1);
arg1.skip(' ', arg0);
double error = 0;
if (arg0.charAt(arg1.getIndex()) == '±') { // Error specified.
arg1.skip('±', arg0);
arg1.skip(' ', arg0);
error = TypeFormat.parseDouble(arg0, arg1);
}
arg1.skip(')', arg0);
arg1.skip(' ', arg0);
Unit unit = UnitFormat.getInstance().parseProductUnit(arg0,
arg1);
return Amount.valueOf(amount, error, unit);
} catch (ParseException e) {
arg1.setIndex(start);
arg1.setErrorIndex(e.getErrorOffset());
return null;
}
}
}
/**
* This class represents the bracket error format.
*/
private static class BracketError extends AmountFormat {
/**
* Holds the number of digits in error.
*/
private int _errorDigits;
/**
* Creates a bracket error format having the specified
* number of digits in error.
*
* @param bracket the number of digits in error.
*/
private BracketError(int errorDigits) {
_errorDigits = errorDigits;
}
@SuppressWarnings("unchecked")
@Override
public Appendable format(Amount arg0, Appendable arg1)
throws IOException {
if (arg0.getUnit() instanceof Currency)
return formatMoney(arg0, arg1);
if (arg0.isExact()) {
TypeFormat.format(arg0.getExactValue(), arg1);
arg1.append(' ');
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
double value = arg0.getEstimatedValue();
double error = arg0.getAbsoluteError();
int log10Value = (int) MathLib.floor(MathLib.log10(MathLib
.abs(value)));
int log10Error = (int) MathLib.floor(MathLib.log10(error));
int digits = log10Value - log10Error - 1; // Exact digits.
digits = MathLib.max(1, digits + _errorDigits);
boolean scientific = (MathLib.abs(value) >= 1E6)
|| (MathLib.abs(value) < 1E-6);
boolean showZeros = true;
TextBuilder tb = TextBuilder.newInstance();
TypeFormat.format(value, digits, scientific, showZeros, tb);
int endMantissa = 0;
for (; endMantissa < tb.length(); endMantissa++) {
if (tb.charAt(endMantissa) == 'E')
break;
}
int bracketError = (int) (error * MathLib.toDoublePow10(1,
-log10Error + _errorDigits - 1));
tb.insert(endMantissa, Text.valueOf('[').plus(
Text.valueOf(bracketError)).plus(']'));
arg1.append(tb);
arg1.append(' ');
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
@Override
public Amount parse(CharSequence arg0, Cursor arg1) {
// TBD
throw new UnsupportedOperationException("Not supported yet");
}
}
/**
* This class represents the exact digits only format.
*/
private static class ExactDigitsOnly extends AmountFormat {
/**
* Default constructor.
*/
private ExactDigitsOnly() {
}
@SuppressWarnings("unchecked")
@Override
public Appendable format(Amount arg0, Appendable arg1)
throws IOException {
if (arg0.getUnit() instanceof Currency)
return formatMoney(arg0, arg1);
if (arg0.isExact()) {
TypeFormat.format(arg0.getExactValue(), arg1);
arg1.append(' ');
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
double value = arg0.getEstimatedValue();
double error = arg0.getAbsoluteError();
int log10Value = (int) MathLib.floor(MathLib.log10(MathLib
.abs(value)));
int log10Error = (int) MathLib.floor(MathLib.log10(error));
int digits = log10Value - log10Error - 1; // Exact digits.
boolean scientific = (MathLib.abs(value) >= 1E6)
|| (MathLib.abs(value) < 1E-6);
boolean showZeros = true;
TypeFormat.format(value, digits, scientific, showZeros, arg1);
arg1.append(' ');
return UnitFormat.getInstance().format(arg0.getUnit(), arg1);
}
@Override
public Amount parse(CharSequence arg0, Cursor arg1) {
throw new UnsupportedOperationException(
"This format should not be used for parsing "
+ "(not enough information on the error");
}
}
/**
* Provides custom formatting for money measurements.
*/
private static Appendable formatMoney(Amount arg0, Appendable arg1)
throws IOException {
Currency currency = (Currency) arg0.getUnit();
int fraction = currency.getDefaultFractionDigits();
if (fraction == 0) {
long amount = arg0.longValue(currency);
TypeFormat.format(amount, arg1);
} else if (fraction == 2) {
long amount = MathLib.round(arg0.doubleValue(arg0.getUnit()) * 100);
TypeFormat.format(amount / 100, arg1);
arg1.append('.');
arg1.append((char) ('0' + (amount % 100) / 10));
arg1.append((char) ('0' + (amount % 10)));
} else {
throw new UnsupportedOperationException();
}
arg1.append(' ');
return UnitFormat.getInstance().format(currency, arg1);
}
}
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