Check in the pristine copy of ICU 4.6...

icu46/source/i18n/locdspnm.cpp

+/*
+*******************************************************************************
+* Copyright (C) 2010, International Business Machines Corporation and         *
+* others. All Rights Reserved.                                                *
+*******************************************************************************
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/locdspnm.h"
+
+#include "unicode/msgfmt.h"
+
+#include "cmemory.h"
+#include "cstring.h"
+#include "ulocimp.h"
+#include "ureslocs.h"
+
+#include <stdarg.h>
+
+/**
+ * Concatenate a number of null-terminated strings to buffer, leaving a
+ * null-terminated string.  The last argument should be the null pointer.
+ * Return the length of the string in the buffer, not counting the trailing
+ * null.  Return -1 if there is an error (buffer is null, or buflen < 1).
+ */
+static int32_t ncat(char *buffer, uint32_t buflen, ...) {
+  va_list args;
+  char *str;
+  char *p = buffer;
+  const char* e = buffer + buflen - 1;
+
+  if (buffer == NULL || buflen < 1) {
+    return -1;
+  }
+
+  va_start(args, buflen);
+  while ((str = va_arg(args, char *))) {
+    char c;
+    while (p != e && (c = *str++)) {
+      *p++ = c;
+    }
+  }
+  *p = 0;
+  va_end(args);
+
+  return p - buffer;
+}
+
+U_NAMESPACE_BEGIN
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+// Access resource data for locale components.
+// Wrap code in uloc.c for now.
+class ICUDataTable {
+  const char* path;
+  Locale locale;
+
+public:
+  ICUDataTable(const char* path, const Locale& locale);
+  ~ICUDataTable();
+
+  const Locale& getLocale();
+
+  UnicodeString& get(const char* tableKey, const char* itemKey,
+                     UnicodeString& result) const;
+  UnicodeString& get(const char* tableKey, const char* subTableKey, const char* itemKey,
+                     UnicodeString& result) const;
+
+  UnicodeString& getNoFallback(const char* tableKey, const char* itemKey,
+                               UnicodeString &result) const;
+  UnicodeString& getNoFallback(const char* tableKey, const char* subTableKey, const char* itemKey,
+                               UnicodeString &result) const;
+};
+
+inline UnicodeString &
+ICUDataTable::get(const char* tableKey, const char* itemKey, UnicodeString& result) const {
+  return get(tableKey, NULL, itemKey, result);
+}
+
+inline UnicodeString &
+ICUDataTable::getNoFallback(const char* tableKey, const char* itemKey, UnicodeString& result) const {
+  return getNoFallback(tableKey, NULL, itemKey, result);
+}
+
+ICUDataTable::ICUDataTable(const char* path, const Locale& locale)
+  : path(NULL), locale(Locale::getRoot())
+{
+  if (path) {
+    int32_t len = uprv_strlen(path);
+    this->path = (const char*) uprv_malloc(len + 1);
+    if (this->path) {
+      uprv_strcpy((char *)this->path, path);
+      this->locale = locale;
+    }
+  }
+}
+
+ICUDataTable::~ICUDataTable() {
+  if (path) {
+    uprv_free((void*) path);
+    path = NULL;
+  }
+}
+
+const Locale&
+ICUDataTable::getLocale() {
+  return locale;
+}
+
+UnicodeString &
+ICUDataTable::get(const char* tableKey, const char* subTableKey, const char* itemKey,
+                  UnicodeString &result) const {
+  UErrorCode status = U_ZERO_ERROR;
+  int32_t len = 0;
+
+  const UChar *s = uloc_getTableStringWithFallback(path, locale.getName(),
+                                                   tableKey, subTableKey, itemKey,
+                                                   &len, &status);
+  if (U_SUCCESS(status)) {
+    return result.setTo(s, len);
+  }
+  return result.setTo(UnicodeString(itemKey, -1, US_INV));
+}
+
+UnicodeString &
+ICUDataTable::getNoFallback(const char* tableKey, const char* subTableKey, const char* itemKey,
+                            UnicodeString& result) const {
+  UErrorCode status = U_ZERO_ERROR;
+  int32_t len = 0;
+
+  const UChar *s = uloc_getTableStringWithFallback(path, locale.getName(),
+                                                   tableKey, subTableKey, itemKey,
+                                                   &len, &status);
+  if (U_SUCCESS(status)) {
+    return result.setTo(s, len);
+  }
+
+  result.setToBogus();
+  return result;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+UOBJECT_DEFINE_NO_RTTI_IMPLEMENTATION(LocaleDisplayNames)
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+#if 0  // currently unused
+
+class DefaultLocaleDisplayNames : public LocaleDisplayNames {
+  UDialectHandling dialectHandling;
+
+public:
+  // constructor
+  DefaultLocaleDisplayNames(UDialectHandling dialectHandling);
+
+  virtual ~DefaultLocaleDisplayNames();
+
+  virtual const Locale& getLocale() const;
+  virtual UDialectHandling getDialectHandling() const;
+  virtual UnicodeString& localeDisplayName(const Locale& locale,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& localeDisplayName(const char* localeId,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& languageDisplayName(const char* lang,
+                                             UnicodeString& result) const;
+  virtual UnicodeString& scriptDisplayName(const char* script,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& scriptDisplayName(UScriptCode scriptCode,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& regionDisplayName(const char* region,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& variantDisplayName(const char* variant,
+                                            UnicodeString& result) const;
+  virtual UnicodeString& keyDisplayName(const char* key,
+                                        UnicodeString& result) const;
+  virtual UnicodeString& keyValueDisplayName(const char* key,
+                                             const char* value,
+                                             UnicodeString& result) const;
+};
+
+DefaultLocaleDisplayNames::DefaultLocaleDisplayNames(UDialectHandling dialectHandling)
+    : dialectHandling(dialectHandling) {
+}
+
+DefaultLocaleDisplayNames::~DefaultLocaleDisplayNames() {
+}
+
+const Locale&
+DefaultLocaleDisplayNames::getLocale() const {
+  return Locale::getRoot();
+}
+
+UDialectHandling
+DefaultLocaleDisplayNames::getDialectHandling() const {
+  return dialectHandling;
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::localeDisplayName(const Locale& locale,
+                                             UnicodeString& result) const {
+  return result = UnicodeString(locale.getName(), -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::localeDisplayName(const char* localeId,
+                                             UnicodeString& result) const {
+  return result = UnicodeString(localeId, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::languageDisplayName(const char* lang,
+                                               UnicodeString& result) const {
+  return result = UnicodeString(lang, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::scriptDisplayName(const char* script,
+                                             UnicodeString& result) const {
+  return result = UnicodeString(script, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::scriptDisplayName(UScriptCode scriptCode,
+                                             UnicodeString& result) const {
+  const char* name = uscript_getName(scriptCode);
+  if (name) {
+    return result = UnicodeString(name, -1, US_INV);
+  }
+  return result.remove();
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::regionDisplayName(const char* region,
+                                             UnicodeString& result) const {
+  return result = UnicodeString(region, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::variantDisplayName(const char* variant,
+                                              UnicodeString& result) const {
+  return result = UnicodeString(variant, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::keyDisplayName(const char* key,
+                                          UnicodeString& result) const {
+  return result = UnicodeString(key, -1, US_INV);
+}
+
+UnicodeString&
+DefaultLocaleDisplayNames::keyValueDisplayName(const char* /* key */,
+                                               const char* value,
+                                               UnicodeString& result) const {
+  return result = UnicodeString(value, -1, US_INV);
+}
+
+#endif  // currently unused class DefaultLocaleDisplayNames
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+class LocaleDisplayNamesImpl : public LocaleDisplayNames {
+  Locale locale;
+  UDialectHandling dialectHandling;
+  ICUDataTable langData;
+  ICUDataTable regionData;
+  UnicodeString sep;
+  MessageFormat *format;
+
+public:
+  // constructor
+  LocaleDisplayNamesImpl(const Locale& locale, UDialectHandling dialectHandling);
+  virtual ~LocaleDisplayNamesImpl();
+
+  virtual const Locale& getLocale() const;
+  virtual UDialectHandling getDialectHandling() const;
+
+  virtual UnicodeString& localeDisplayName(const Locale& locale,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& localeDisplayName(const char* localeId,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& languageDisplayName(const char* lang,
+                                             UnicodeString& result) const;
+  virtual UnicodeString& scriptDisplayName(const char* script,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& scriptDisplayName(UScriptCode scriptCode,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& regionDisplayName(const char* region,
+                                           UnicodeString& result) const;
+  virtual UnicodeString& variantDisplayName(const char* variant,
+                                            UnicodeString& result) const;
+  virtual UnicodeString& keyDisplayName(const char* key,
+                                        UnicodeString& result) const;
+  virtual UnicodeString& keyValueDisplayName(const char* key,
+                                             const char* value,
+                                             UnicodeString& result) const;
+private:
+  UnicodeString& localeIdName(const char* localeId,
+                              UnicodeString& result) const;
+  UnicodeString& appendWithSep(UnicodeString& buffer, const UnicodeString& src) const;
+};
+
+LocaleDisplayNamesImpl::LocaleDisplayNamesImpl(const Locale& locale,
+                                               UDialectHandling dialectHandling)
+  : dialectHandling(dialectHandling)
+  , langData(U_ICUDATA_LANG, locale)
+  , regionData(U_ICUDATA_REGION, locale)
+  , format(NULL)
+{
+  LocaleDisplayNamesImpl *nonConstThis = (LocaleDisplayNamesImpl *)this;
+  nonConstThis->locale = langData.getLocale() == Locale::getRoot()
+    ? regionData.getLocale()
+    : langData.getLocale();
+
+  langData.getNoFallback("localeDisplayPattern", "separator", sep);
+  if (sep.isBogus()) {
+    sep = UnicodeString(", ", -1, US_INV);
+  }
+
+  UnicodeString pattern;
+  langData.getNoFallback("localeDisplayPattern", "pattern", pattern);
+  if (pattern.isBogus()) {
+    pattern = UnicodeString("{0} ({1})", -1, US_INV);
+  }
+  UErrorCode status = U_ZERO_ERROR;
+  format = new MessageFormat(pattern, status);
+}
+
+LocaleDisplayNamesImpl::~LocaleDisplayNamesImpl() {
+  delete format;
+}
+
+const Locale&
+LocaleDisplayNamesImpl::getLocale() const {
+  return locale;
+}
+
+UDialectHandling
+LocaleDisplayNamesImpl::getDialectHandling() const {
+  return dialectHandling;
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::localeDisplayName(const Locale& locale,
+                                          UnicodeString& result) const {
+  UnicodeString resultName;
+
+  const char* lang = locale.getLanguage();
+  if (uprv_strlen(lang) == 0) {
+    lang = "root";
+  }
+  const char* script = locale.getScript();
+  const char* country = locale.getCountry();
+  const char* variant = locale.getVariant();
+
+  UBool hasScript = uprv_strlen(script) > 0;
+  UBool hasCountry = uprv_strlen(country) > 0;
+  UBool hasVariant = uprv_strlen(variant) > 0;
+
+  if (dialectHandling == ULDN_DIALECT_NAMES) {
+    char buffer[ULOC_FULLNAME_CAPACITY];
+    do { // loop construct is so we can break early out of search
+      if (hasScript && hasCountry) {
+        ncat(buffer, ULOC_FULLNAME_CAPACITY, lang, "_", script, "_", country, (char *)0);
+        localeIdName(buffer, resultName);
+        if (!resultName.isBogus()) {
+          hasScript = FALSE;
+          hasCountry = FALSE;
+          break;
+        }
+      }
+      if (hasScript) {
+        ncat(buffer, ULOC_FULLNAME_CAPACITY, lang, "_", script, (char *)0);
+        localeIdName(buffer, resultName);
+        if (!resultName.isBogus()) {
+          hasScript = FALSE;
+          break;
+        }
+      }
+      if (hasCountry) {
+        ncat(buffer, ULOC_FULLNAME_CAPACITY, lang, "_", country, (char*)0);
+        localeIdName(buffer, resultName);
+        if (!resultName.isBogus()) {
+          hasCountry = FALSE;
+          break;
+        }
+      }
+    } while (FALSE);
+  }
+  if (resultName.isBogus() || resultName.isEmpty()) {
+    localeIdName(lang, resultName);
+  }
+
+  UnicodeString resultRemainder;
+  UnicodeString temp;
+  StringEnumeration *e = NULL;
+  UErrorCode status = U_ZERO_ERROR;
+
+  if (hasScript) {
+    resultRemainder.append(scriptDisplayName(script, temp));
+  }
+  if (hasCountry) {
+    appendWithSep(resultRemainder, regionDisplayName(country, temp));
+  }
+  if (hasVariant) {
+    appendWithSep(resultRemainder, variantDisplayName(variant, temp));
+  }
+
+  e = locale.createKeywords(status);
+  if (e && U_SUCCESS(status)) {
+    UnicodeString temp2;
+    char value[ULOC_KEYWORD_AND_VALUES_CAPACITY]; // sigh, no ULOC_VALUE_CAPACITY
+    const char* key;
+    while ((key = e->next((int32_t *)0, status)) != NULL) {
+      locale.getKeywordValue(key, value, ULOC_KEYWORD_AND_VALUES_CAPACITY, status);
+      appendWithSep(resultRemainder, keyDisplayName(key, temp))
+          .append("=")
+          .append(keyValueDisplayName(key, value, temp2));
+    }
+    delete e;
+  }
+
+  if (!resultRemainder.isEmpty()) {
+    Formattable data[] = {
+      resultName,
+      resultRemainder
+    };
+    FieldPosition fpos;
+    status = U_ZERO_ERROR;
+    format->format(data, 2, result, fpos, status);
+    return result;
+  }
+
+  return result = resultName;
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::appendWithSep(UnicodeString& buffer, const UnicodeString& src) const {
+  if (!buffer.isEmpty()) {
+    buffer.append(sep);
+  }
+  buffer.append(src);
+  return buffer;
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::localeDisplayName(const char* localeId,
+                                          UnicodeString& result) const {
+  return localeDisplayName(Locale(localeId), result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::localeIdName(const char* localeId,
+                                     UnicodeString& result) const {
+  return langData.getNoFallback("Languages", localeId, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::languageDisplayName(const char* lang,
+                                            UnicodeString& result) const {
+  if (uprv_strcmp("root", lang) == 0 || uprv_strchr(lang, '_') != NULL) {
+    return result = UnicodeString(lang, -1, US_INV);
+  }
+  return langData.get("Languages", lang, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::scriptDisplayName(const char* script,
+                                          UnicodeString& result) const {
+  return langData.get("Scripts", script, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::scriptDisplayName(UScriptCode scriptCode,
+                                          UnicodeString& result) const {
+  const char* name = uscript_getName(scriptCode);
+  return langData.get("Scripts", name, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::regionDisplayName(const char* region,
+                                          UnicodeString& result) const {
+  return regionData.get("Countries", region, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::variantDisplayName(const char* variant,
+                                           UnicodeString& result) const {
+  return langData.get("Variants", variant, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::keyDisplayName(const char* key,
+                                       UnicodeString& result) const {
+  return langData.get("Keys", key, result);
+}
+
+UnicodeString&
+LocaleDisplayNamesImpl::keyValueDisplayName(const char* key,
+                                            const char* value,
+                                            UnicodeString& result) const {
+  return langData.get("Types", key, value, result);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+LocaleDisplayNames*
+LocaleDisplayNames::createInstance(const Locale& locale,
+                                   UDialectHandling dialectHandling) {
+  return new LocaleDisplayNamesImpl(locale, dialectHandling);
+}
+
+U_NAMESPACE_END
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+U_NAMESPACE_USE
+
+U_DRAFT ULocaleDisplayNames * U_EXPORT2
+uldn_open(const char * locale,
+          UDialectHandling dialectHandling,
+          UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (locale == NULL) {
+    locale = uloc_getDefault();
+  }
+  return (ULocaleDisplayNames *)LocaleDisplayNames::createInstance(Locale(locale), dialectHandling);
+}
+
+U_DRAFT void U_EXPORT2
+uldn_close(ULocaleDisplayNames *ldn) {
+  delete (LocaleDisplayNames *)ldn;
+}
+
+U_DRAFT const char * U_EXPORT2
+uldn_getLocale(const ULocaleDisplayNames *ldn) {
+  if (ldn) {
+    return ((const LocaleDisplayNames *)ldn)->getLocale().getName();
+  }
+  return NULL;
+}
+
+U_DRAFT UDialectHandling U_EXPORT2
+uldn_getDialectHandling(const ULocaleDisplayNames *ldn) {
+  if (ldn) {
+    return ((const LocaleDisplayNames *)ldn)->getDialectHandling();
+  }
+  return ULDN_STANDARD_NAMES;
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_localeDisplayName(const ULocaleDisplayNames *ldn,
+                       const char *locale,
+                       UChar *result,
+                       int32_t maxResultSize,
+                       UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || locale == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->localeDisplayName(locale, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_languageDisplayName(const ULocaleDisplayNames *ldn,
+                         const char *lang,
+                         UChar *result,
+                         int32_t maxResultSize,
+                         UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || lang == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->languageDisplayName(lang, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_scriptDisplayName(const ULocaleDisplayNames *ldn,
+                       const char *script,
+                       UChar *result,
+                       int32_t maxResultSize,
+                       UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || script == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->scriptDisplayName(script, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_scriptCodeDisplayName(const ULocaleDisplayNames *ldn,
+                           UScriptCode scriptCode,
+                           UChar *result,
+                           int32_t maxResultSize,
+                           UErrorCode *pErrorCode) {
+  return uldn_scriptDisplayName(ldn, uscript_getName(scriptCode), result, maxResultSize, pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_regionDisplayName(const ULocaleDisplayNames *ldn,
+                       const char *region,
+                       UChar *result,
+                       int32_t maxResultSize,
+                       UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || region == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->regionDisplayName(region, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_variantDisplayName(const ULocaleDisplayNames *ldn,
+                        const char *variant,
+                        UChar *result,
+                        int32_t maxResultSize,
+                        UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || variant == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->variantDisplayName(variant, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_keyDisplayName(const ULocaleDisplayNames *ldn,
+                    const char *key,
+                    UChar *result,
+                    int32_t maxResultSize,
+                    UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || key == NULL || (result == NULL && maxResultSize > 0) || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->keyDisplayName(key, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+U_DRAFT int32_t U_EXPORT2
+uldn_keyValueDisplayName(const ULocaleDisplayNames *ldn,
+                         const char *key,
+                         const char *value,
+                         UChar *result,
+                         int32_t maxResultSize,
+                         UErrorCode *pErrorCode) {
+  if (U_FAILURE(*pErrorCode)) {
+    return 0;
+  }
+  if (ldn == NULL || key == NULL || value == NULL || (result == NULL && maxResultSize > 0)
+      || maxResultSize < 0) {
+    *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR;
+    return 0;
+  }
+  UnicodeString temp(result, 0, maxResultSize);
+  ((const LocaleDisplayNames *)ldn)->keyValueDisplayName(key, value, temp);
+  return temp.extract(result, maxResultSize, *pErrorCode);
+}
+
+#endif