/*
*******************************************************************************
* Copyright (C) 2009, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*/
package com.ibm.icu.text;
import java.util.ArrayList;
import java.util.Locale;
import java.util.MissingResourceException;
import com.ibm.icu.impl.ICUResourceBundle;
import com.ibm.icu.lang.UCharacter;
import com.ibm.icu.util.ULocale;
import com.ibm.icu.util.UResourceBundle;
import com.ibm.icu.util.UResourceBundleIterator;
import com.ibm.icu.text.UCharacterIterator;
/**
* <code>NumberingSystem</code> is the base class for all number
* systems. This class provides the interface for setting different numbering
* system types, whether it be a simple alternate digit system such as
* Thai digits or Devanagari digits, or an algorithmic numbering system such
* as Hebrew numbering or Chinese numbering.
*
* @author John Emmons
* @draft ICU 4.2
*/
class NumberingSystem {
/**
* Default constructor. Returns a numbering system that uses the Western decimal
* digits 0 through 9.
* @draft ICU 4.2
*/
public NumberingSystem() {
radix = 10;
algorithmic = false;
desc = "0123456789";
}
/**
* Factory method for creating a numbering system.
* @param radix_in The radix for this numbering system. ICU currently
* supports only numbering systems whose radix is 10.
* @param isAlgorithmic_in Specifies whether the numbering system is algorithmic
* (true) or numeric (false).
* @param desc_in String used to describe the characteristics of the numbering
* system. For numeric systems, this string contains the digits used by the
* numbering system, in order, starting from zero. For algorithmic numbering
* systems, the string contains the name of the RBNF ruleset in the locale's
* NumberingSystemRules section that will be used to format numbers using
* this numbering system.
* @draft ICU 4.2
*/
public static NumberingSystem getInstance(int radix_in, boolean isAlgorithmic_in, String desc_in ) {
if ( radix_in < 2 ) {
throw new IllegalArgumentException("Invalid radix for numbering system");
}
if ( !isAlgorithmic_in ) {
if ( desc_in.length() != radix_in || !isValidDigitString(desc_in)) {
throw new IllegalArgumentException("Invalid digit string for numbering system");
}
}
NumberingSystem ns = new NumberingSystem();
ns.radix = radix_in;
ns.algorithmic = isAlgorithmic_in;
ns.desc = desc_in;
return ns;
}
/**
* Returns the default numbering system for the specified locale.
* @draft ICU 4.2
*/
public static NumberingSystem getInstance(Locale inLocale) {
return getInstance(ULocale.forLocale(inLocale));
}
/**
* Returns the default numbering system for the specified ULocale.
* @draft ICU 4.2
*/
public static NumberingSystem getInstance(ULocale locale) {
String numbersKeyword = locale.getKeywordValue("numbers");
if (numbersKeyword != null) {
NumberingSystem ns = getInstanceByName(numbersKeyword);
if ( ns != null ) {
return ns;
}
}
String defaultNumberingSystem;
try {
ICUResourceBundle rb = (ICUResourceBundle)UResourceBundle.getBundleInstance(ICUResourceBundle.ICU_BASE_NAME,locale);
defaultNumberingSystem = rb.getString("defaultNumberingSystem");
} catch (MissingResourceException ex) {
return new NumberingSystem();
}
NumberingSystem ns = getInstanceByName(defaultNumberingSystem);
if ( ns != null ) {
return ns;
}
return new NumberingSystem();
}
/**
* Returns the default numbering system for the default locale.
* @draft ICU 4.2
*/
public static NumberingSystem getInstance() {
return getInstance(ULocale.getDefault());
}
/**
* Returns a numbering system from one of the predefined numbering systems
* known to ICU. Numbering system names are based on the numbering systems
* defined in CLDR. To get a list of available numbering systems, use the
* getAvailableNames method.
* @param name The name of the desired numbering system. Numbering system
* names often correspond with the name of the script they are associated
* with. For example, "thai" for Thai digits, "hebr" for Hebrew numerals.
* @draft ICU 4.2
*/
public static NumberingSystem getInstanceByName(String name) {
int radix;
boolean isAlgorithmic;
String description;
try {
UResourceBundle numberingSystemsInfo = UResourceBundle.getBundleInstance(ICUResourceBundle.ICU_BASE_NAME, "numberingSystems");
UResourceBundle nsCurrent = numberingSystemsInfo.get("numberingSystems");
UResourceBundle nsTop = nsCurrent.get(name);
description = nsTop.getString("desc");
UResourceBundle nsRadixBundle = nsTop.get("radix");
UResourceBundle nsAlgBundle = nsTop.get("algorithmic");
radix = nsRadixBundle.getInt();
int algorithmic = nsAlgBundle.getInt();
isAlgorithmic = ( algorithmic == 1 );
} catch (MissingResourceException ex) {
return null;
}
return getInstance(radix,isAlgorithmic,description);
}
/**
* Returns a string array containing a list of the names of numbering systems
* currently known to ICU.
* @draft ICU 4.2
*/
public static String [] getAvailableNames() {
UResourceBundle numberingSystemsInfo = UResourceBundle.getBundleInstance(ICUResourceBundle.ICU_BASE_NAME, "numberingSystems");
UResourceBundle nsCurrent = numberingSystemsInfo.get("numberingSystems");
UResourceBundle temp;
String nsName;
ArrayList output = new ArrayList();
UResourceBundleIterator it = nsCurrent.getIterator();
while (it.hasNext()) {
temp = it.next();
nsName = temp.getKey();
output.add(nsName);
}
return (String[]) output.toArray(new String[output.size()]);
}
/**
* Convenience method to determine if a given digit string is valid for use as a
* descriptor of a numeric ( non-algorithmic ) numbering system. In order for
* a digit string to be valid, it must meet the following criteria:
* 1. It must only contain characters that are decimal digits as defined by Unicode.
* 2. It must contain characters that are contiguous code points.
* 3. Digits must be in Unicode's basic multilingual plane.
* @draft ICU 4.2
*/
public static boolean isValidDigitString(String str) {
int c;
int prev = 0;
int i = 0;
UCharacterIterator it = UCharacterIterator.getInstance(str);
it.setToStart();
while ( (c = it.nextCodePoint()) != UCharacterIterator.DONE) {
if ( UCharacter.digit(c) != i ) { // Digits outside the Unicode decimal digit class are not currently supported
return false;
}
if ( prev != 0 && c != prev + 1 ) { // Non-contiguous digits are not currently supported
return false;
}
if ( UCharacter.isSupplementary(c)) { // Digits outside the BMP are not currently supported
return false;
}
i++;
prev = c;
}
return true;
}
/**
* Returns the radix of the current numbering system.
* @draft ICU 4.2
*/
public int getRadix() {
return radix;
}
/**
* Returns the description string of the current numbering system.
* The description string describes the characteristics of the numbering
* system. For numeric systems, this string contains the digits used by the
* numbering system, in order, starting from zero. For algorithmic numbering
* systems, the string contains the name of the RBNF ruleset in the locale's
* NumberingSystemRules section that will be used to format numbers using
* this numbering system.
* @draft ICU 4.2
*/
public String getDescription() {
return desc;
}
/**
* Returns the numbering system's algorithmic status. If true,
* the numbering system is algorithmic and uses an RBNF formatter to
* format numerals. If false, the numbering system is numeric and
* uses a fixed set of digits.
* @draft ICU 4.2
*/
public boolean isAlgorithmic() {
return algorithmic;
}
private String desc;
private int radix;
private boolean algorithmic;
}