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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.util.locale.provider;

import java.util.Locale;
import java.util.Set;
import java.util.spi.LocaleNameProvider;

/**
 * Concrete implementation of the
 * {@link java.util.spi.LocaleNameProvider LocaleNameProvider} class
 * for the JRE LocaleProviderAdapter.
 *
 * @author Naoto Sato
 * @author Masayoshi Okutsu
 */
public class LocaleNameProviderImpl extends LocaleNameProvider implements AvailableLanguageTags {
    private final LocaleProviderAdapter.Type type;
    private Set<String> langtags;

    public LocaleNameProviderImpl(LocaleProviderAdapter.Type type) {
        this.type = type;
    }

    /**
     * Returns an array of all locales for which this locale service provider
     * can provide localized objects or names.
     *
     * @return An array of all locales for which this locale service provider
     * can provide localized objects or names.
     */
    @Override
    public Locale[] getAvailableLocales() {
        return LocaleProviderAdapter.toLocaleArray(getLangTags());
    }

    @Override
    public boolean isSupportedLocale(Locale locale) {
        return LocaleProviderAdapter.isSupportedLocale(locale, type, getLangTags());
    }

    /**
     * Returns a localized name for the given ISO 639 language code and the
     * given locale that is appropriate for display to the user.
     * For example, if <code>languageCode</code> is "fr" and <code>locale</code>
     * is en_US, getDisplayLanguage() will return "French"; if <code>languageCode</code>
     * is "en" and <code>locale</code> is fr_FR, getDisplayLanguage() will return "anglais".
     * If the name returned cannot be localized according to <code>locale</code>,
     * (say, the provider does not have a Japanese name for Croatian),
     * this method returns null.
     * @param languageCode the ISO 639 language code string in the form of two
     *     lower-case letters between 'a' (U+0061) and 'z' (U+007A)
     * @param locale the desired locale
     * @return the name of the given language code for the specified locale, or null if it's not
     *     available.
     * @exception NullPointerException if <code>languageCode</code> or <code>locale</code> is null
     * @exception IllegalArgumentException if <code>languageCode</code> is not in the form of
     *     two lower-case letters, or <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @see java.util.Locale#getDisplayLanguage(java.util.Locale)
     */
    @Override
    public String getDisplayLanguage(String languageCode, Locale locale) {
        return getDisplayString(languageCode, locale);
    }

    /**
     * Returns a localized name for the given <a href="http://www.rfc-editor.org/rfc/bcp/bcp47.txt">
     * IETF BCP47</a> script code and the given locale that is appropriate for
     * display to the user.
     * For example, if <code>scriptCode</code> is "Latn" and <code>locale</code>
     * is en_US, getDisplayScript() will return "Latin"; if <code>scriptCode</code>
     * is "Cyrl" and <code>locale</code> is fr_FR, getDisplayScript() will return "cyrillique".
     * If the name returned cannot be localized according to <code>locale</code>,
     * (say, the provider does not have a Japanese name for Cyrillic),
     * this method returns null. The default implementation returns null.
     * @param scriptCode the four letter script code string in the form of title-case
     *     letters (the first letter is upper-case character between 'A' (U+0041) and
     *     'Z' (U+005A) followed by three lower-case character between 'a' (U+0061)
     *     and 'z' (U+007A)).
     * @param locale the desired locale
     * @return the name of the given script code for the specified locale, or null if it's not
     *     available.
     * @exception NullPointerException if <code>scriptCode</code> or <code>locale</code> is null
     * @exception IllegalArgumentException if <code>scriptCode</code> is not in the form of
     *     four title case letters, or <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @see java.util.Locale#getDisplayScript(java.util.Locale)
     */
    @Override
    public String getDisplayScript(String scriptCode, Locale locale) {
        return getDisplayString(scriptCode, locale);
    }

    /**
     * Returns a localized name for the given ISO 3166 country code and the
     * given locale that is appropriate for display to the user.
     * For example, if <code>countryCode</code> is "FR" and <code>locale</code>
     * is en_US, getDisplayCountry() will return "France"; if <code>countryCode</code>
     * is "US" and <code>locale</code> is fr_FR, getDisplayCountry() will return "Etats-Unis".
     * If the name returned cannot be localized according to <code>locale</code>,
     * (say, the provider does not have a Japanese name for Croatia),
     * this method returns null.
     * @param countryCode the ISO 3166 country code string in the form of two
     *     upper-case letters between 'A' (U+0041) and 'Z' (U+005A)
     * @param locale the desired locale
     * @return the name of the given country code for the specified locale, or null if it's not
     *     available.
     * @exception NullPointerException if <code>countryCode</code> or <code>locale</code> is null
     * @exception IllegalArgumentException if <code>countryCode</code> is not in the form of
     *     two upper-case letters, or <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @see java.util.Locale#getDisplayCountry(java.util.Locale)
     */
    @Override
    public String getDisplayCountry(String countryCode, Locale locale) {
        return getDisplayString(countryCode, locale);
    }

    /**
     * Returns a localized name for the given variant code and the given locale that
     * is appropriate for display to the user.
     * If the name returned cannot be localized according to <code>locale</code>,
     * this method returns null.
     * @param variant the variant string
     * @param locale the desired locale
     * @return the name of the given variant string for the specified locale, or null if it's not
     *     available.
     * @exception NullPointerException if <code>variant</code> or <code>locale</code> is null
     * @exception IllegalArgumentException if <code>locale</code> isn't
     *     one of the locales returned from
     *     {@link java.util.spi.LocaleServiceProvider#getAvailableLocales()
     *     getAvailableLocales()}.
     * @see java.util.Locale#getDisplayVariant(java.util.Locale)
     */
    @Override
    public String getDisplayVariant(String variant, Locale locale) {
        return getDisplayString("%%"+variant, locale);
    }

    private String getDisplayString(String key, Locale locale) {
        if (key == null || locale == null) {
            throw new NullPointerException();
        }

        return LocaleProviderAdapter.forType(type).getLocaleResources(locale).getLocaleName(key);
    }

    @Override
    public Set<String> getAvailableLanguageTags() {
        return getLangTags();
    }

    private Set<String> getLangTags() {
        if (langtags == null) {
            langtags = ((JRELocaleProviderAdapter)LocaleProviderAdapter.forType(type)).getLanguageTagSet("LocaleNames");
        }
        return langtags;
    }
}