com.ibm.icu.text.CompactDecimalFormat Maven / Gradle / Ivy
Show all versions of icu4j Show documentation
/*
*******************************************************************************
* Copyright (C) 1996-2012, Google, International Business Machines Corporation and
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.text;
import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.AttributedCharacterIterator;
import java.text.FieldPosition;
import java.text.ParsePosition;
import java.util.Collection;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import com.ibm.icu.text.CompactDecimalDataCache.Data;
import com.ibm.icu.util.ULocale;
/**
* The CompactDecimalFormat produces abbreviated numbers, suitable for display in environments will limited real estate.
* For example, 'Hits: 1.2B' instead of 'Hits: 1,200,000,000'. The format will be appropriate for the given language,
* such as "1,2 Mrd." for German.
*
* For numbers under 1000 trillion (under 10^15, such as 123,456,789,012,345), the result will be short for supported
* languages. However, the result may sometimes exceed 7 characters, such as when there are combining marks or thin
* characters. In such cases, the visual width in fonts should still be short.
*
* By default, there are 2 significant digits. After creation, if more than three significant digits are set (with
* setMaximumSignificantDigits), or if a fixed number of digits are set (with setMaximumIntegerDigits or
* setMaximumFractionDigits), then result may be wider.
*
* At this time, negative numbers and parsing are not supported, and will produce an UnsupportedOperationException.
* Resetting the pattern prefixes or suffixes is not supported; the method calls are ignored.
*
* Note that important methods, like setting the number of decimals, will be moved up from DecimalFormat to
* NumberFormat.
*
* @author markdavis
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
public class CompactDecimalFormat extends DecimalFormat {
private static final long serialVersionUID = 4716293295276629682L;
private static final int POSITIVE_PREFIX = 0, POSITIVE_SUFFIX = 1, AFFIX_SIZE = 2;
private static final CompactDecimalDataCache cache = new CompactDecimalDataCache();
private final Map units;
private final long[] divisor;
private final String[] currencyAffixes;
// null if created internally using explicit prefixes and suffixes.
private final PluralRules pluralRules;
/**
* Style parameter for CompactDecimalFormat.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public enum CompactStyle {
/**
* Short version, like "1.2T"
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
SHORT,
/**
* Longer version, like "1.2 trillion", if available. May return same result as SHORT if not.
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
LONG
}
/**
* Create a CompactDecimalFormat appropriate for a locale. The result may
* be affected by the number system in the locale, such as ar-u-nu-latn.
*
* @param locale the desired locale
* @param style the compact style
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public static CompactDecimalFormat getInstance(ULocale locale, CompactStyle style) {
return new CompactDecimalFormat(locale, style);
}
/**
* Create a CompactDecimalFormat appropriate for a locale. The result may
* be affected by the number system in the locale, such as ar-u-nu-latn.
*
* @param locale the desired locale
* @param style the compact style
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
public static CompactDecimalFormat getInstance(Locale locale, CompactStyle style) {
return new CompactDecimalFormat(ULocale.forLocale(locale), style);
}
/**
* The public mechanism is CompactDecimalFormat.getInstance().
*
* @param locale
* the desired locale
* @param style
* the compact style
*/
CompactDecimalFormat(ULocale locale, CompactStyle style) {
DecimalFormat format = (DecimalFormat) NumberFormat.getInstance(locale);
CompactDecimalDataCache.Data data = getData(locale, style);
this.units = data.units;
this.divisor = data.divisors;
applyPattern(format.toPattern());
setDecimalFormatSymbols(format.getDecimalFormatSymbols());
setMaximumSignificantDigits(2); // default significant digits
setSignificantDigitsUsed(true);
setGroupingUsed(false);
this.pluralRules = PluralRules.forLocale(locale);
DecimalFormat currencyFormat = (DecimalFormat) NumberFormat.getCurrencyInstance(locale);
currencyAffixes = new String[AFFIX_SIZE];
currencyAffixes[CompactDecimalFormat.POSITIVE_PREFIX] = currencyFormat.getPositivePrefix();
currencyAffixes[CompactDecimalFormat.POSITIVE_SUFFIX] = currencyFormat.getPositiveSuffix();
setCurrency(null);
// TODO fix to get right symbol for the count
}
/**
* Create a short number "from scratch". Intended for internal use. The prefix, suffix, and divisor arrays are
* parallel, and provide the information for each power of 10. When formatting a value, the correct power of 10 is
* found, then the value is divided by the divisor, and the prefix and suffix are set (using
* setPositivePrefix/Suffix).
*
* @param pattern
* A number format pattern. Note that the prefix and suffix are discarded, and the decimals are
* overridden by default.
* @param formatSymbols
* Decimal format symbols, typically from a locale.
* @param prefix
* An array of prefix values, one for each power of 10 from 0 to 14
* @param suffix
* An array of prefix values, one for each power of 10 from 0 to 14
* @param divisor
* An array of prefix values, one for each power of 10 from 0 to 14
* @param debugCreationErrors
* A collection of strings for debugging. If null on input, then any errors found will be added to that
* collection instead of throwing exceptions.
* @internal
*/
public CompactDecimalFormat(String pattern, DecimalFormatSymbols formatSymbols, String[] prefix, String[] suffix,
long[] divisor, Collection debugCreationErrors, CompactStyle style, String[] currencyAffixes) {
if (prefix.length < CompactDecimalDataCache.MAX_DIGITS) {
recordError(debugCreationErrors, "Must have at least " + CompactDecimalDataCache.MAX_DIGITS + " prefix items.");
}
if (prefix.length != suffix.length || prefix.length != divisor.length) {
recordError(debugCreationErrors, "Prefix, suffix, and divisor arrays must have the same length.");
}
long oldDivisor = 0;
Map seen = new HashMap();
for (int i = 0; i < prefix.length; ++i) {
if (prefix[i] == null || suffix[i] == null) {
recordError(debugCreationErrors, "Prefix or suffix is null for " + i);
}
// divisor must be a power of 10, and must be less than or equal to 10^i
int log = (int) Math.log10(divisor[i]);
if (log > i) {
recordError(debugCreationErrors, "Divisor[" + i + "] must be less than or equal to 10^" + i
+ ", but is: " + divisor[i]);
}
long roundTrip = (long) Math.pow(10.0d, log);
if (roundTrip != divisor[i]) {
recordError(debugCreationErrors, "Divisor[" + i + "] must be a power of 10, but is: " + divisor[i]);
}
// we can't have two different indexes with the same display
String key = prefix[i] + "\uFFFF" + suffix[i] + "\uFFFF" + (i - log);
Integer old = seen.get(key);
if (old != null) {
recordError(debugCreationErrors, "Collision between values for " + i + " and " + old
+ " for [prefix/suffix/index-log(divisor)" + key.replace('\uFFFF', ';'));
} else {
seen.put(key, i);
}
if (divisor[i] < oldDivisor) {
recordError(debugCreationErrors, "Bad divisor, the divisor for 10E" + i + "(" + divisor[i]
+ ") is less than the divisor for the divisor for 10E" + (i - 1) + "(" + oldDivisor + ")");
}
oldDivisor = divisor[i];
}
this.units = otherPluralVariant(prefix, suffix);
this.divisor = divisor.clone();
applyPattern(pattern);
setDecimalFormatSymbols(formatSymbols);
setMaximumSignificantDigits(2); // default significant digits
setSignificantDigitsUsed(true);
setGroupingUsed(false);
this.currencyAffixes = currencyAffixes.clone();
this.pluralRules = null;
setCurrency(null);
}
/**
* {@inheritDoc}
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public StringBuffer format(double number, StringBuffer toAppendTo, FieldPosition pos) {
Amount amount = toAmount(number);
Unit unit = amount.getUnit();
unit.writePrefix(toAppendTo);
super.format(amount.getQty(), toAppendTo, pos);
unit.writeSuffix(toAppendTo);
return toAppendTo;
}
/**
* {@inheritDoc}
* @draft ICU 50
* @provisional This API might change or be removed in a future release.
*/
@Override
public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
if (!(obj instanceof Number)) {
throw new IllegalArgumentException();
}
Number number = (Number) obj;
Amount amount = toAmount(number.doubleValue());
return super.formatToCharacterIterator(amount.getQty(), amount.getUnit());
}
/**
* {@inheritDoc}
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public StringBuffer format(long number, StringBuffer toAppendTo, FieldPosition pos) {
return format((double) number, toAppendTo, pos);
}
/**
* {@inheritDoc}
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public StringBuffer format(BigInteger number, StringBuffer toAppendTo, FieldPosition pos) {
return format(number.doubleValue(), toAppendTo, pos);
}
/**
* {@inheritDoc}
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public StringBuffer format(BigDecimal number, StringBuffer toAppendTo, FieldPosition pos) {
return format(number.doubleValue(), toAppendTo, pos);
}
/**
* {@inheritDoc}
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public StringBuffer format(com.ibm.icu.math.BigDecimal number, StringBuffer toAppendTo, FieldPosition pos) {
return format(number.doubleValue(), toAppendTo, pos);
}
/**
* Parsing is currently unsupported, and throws an UnsupportedOperationException.
* @draft ICU 49
* @provisional This API might change or be removed in a future release.
*/
@Override
public Number parse(String text, ParsePosition parsePosition) {
throw new UnsupportedOperationException();
}
// DISALLOW Serialization, at least while draft
private void writeObject(ObjectOutputStream out) throws IOException {
throw new NotSerializableException();
}
private void readObject(ObjectInputStream in) throws IOException {
throw new NotSerializableException();
}
/* INTERNALS */
private Amount toAmount(double number) {
// We do this here so that the prefix or suffix we choose is always consistent
// with the rounding we do. This way, 999999 -> 1M instead of 1000K.
boolean negative = isNumberNegative(number);
number = adjustNumberAsInFormatting(number);
int base = number <= 1.0d ? 0 : (int) Math.log10(number);
if (base >= CompactDecimalDataCache.MAX_DIGITS) {
base = CompactDecimalDataCache.MAX_DIGITS - 1;
}
number /= divisor[base];
String pluralVariant = getPluralForm(number);
if (negative) {
number = -number;
}
return new Amount(
number,
CompactDecimalDataCache.getUnit(units, pluralVariant, base));
}
private void recordError(Collection creationErrors, String errorMessage) {
if (creationErrors == null) {
throw new IllegalArgumentException(errorMessage);
}
creationErrors.add(errorMessage);
}
private Map otherPluralVariant(String[] prefix, String[] suffix) {
Map result = new HashMap();
DecimalFormat.Unit[] units = new DecimalFormat.Unit[prefix.length];
for (int i = 0; i < units.length; i++) {
units[i] = new DecimalFormat.Unit(prefix[i], suffix[i]);
}
result.put(CompactDecimalDataCache.OTHER, units);
return result;
}
private String getPluralForm(double number) {
if (pluralRules == null) {
return CompactDecimalDataCache.OTHER;
}
return pluralRules.select(number);
}
/**
* Gets the data for a particular locale and style. If style is unrecognized,
* we just return data for CompactStyle.SHORT.
* @param locale The locale.
* @param style The style.
* @return The data which must not be modified.
*/
private Data getData(ULocale locale, CompactStyle style) {
CompactDecimalDataCache.DataBundle bundle = cache.get(locale);
switch (style) {
case SHORT:
return bundle.shortData;
case LONG:
return bundle.longData;
default:
return bundle.shortData;
}
}
private static class Amount {
private final double qty;
private final Unit unit;
public Amount(double qty, Unit unit) {
this.qty = qty;
this.unit = unit;
}
public double getQty() {
return qty;
}
public Unit getUnit() {
return unit;
}
}
}