CENOL10n.java

package plugins.CENO;

import freenet.l10n.BaseL10n.LANGUAGE;
import freenet.l10n.PluginL10n;
import freenet.pluginmanager.FredPluginBaseL10n;
import freenet.support.Logger;

/**
 * Provides the methods for localizing Strings, given that a
 * file for a language exists. It is used internally for
 * translating CENO Error messages and other elements that
 * are expected to be presented to users.
 * 
 * Localization files, in the format of properties files, are
 * stored in {@value #L10nFilesBasePath}.
 */
public class CENOL10n implements FredPluginBaseL10n {

	private static PluginL10n l10n;
	private static final CENOL10n INSTANCE = new CENOL10n();

	public static final String L10nFilesBasePath = "/plugins/CENO/resources/l10n/";

	public static CENOL10n getInstance() {
		return INSTANCE;
	}

	private CENOL10n() {
		l10n = new PluginL10n(this); 
	}

	/**
	 * Gets the localized String that corresponds to the given
	 * key, for the set language.
	 * 
	 * @param key the key in the localization file
	 * @return the corresponding localized String
	 */
	public String getString(String key) {
		return l10n.getBase().getString(key);
	}

	/**
	 * Sets the language to be used for localizing Strings
	 * by reading an environment variable.
	 * **Important:** this function will use the value of
	 * the environment variable in the shell that was used
	 * for starting the Freenet node.
	 * 
	 * @param envVar the environment variable to read for
	 * setting the language
	 */
	public void setLanguageFromEnvVar(String envVar) {
		LANGUAGE lang = getLanguageFromEnvVar(envVar);
		if (lang != l10n.getBase().getSelectedLanguage() && lang != LANGUAGE.UNLISTED) {
			setLanguage(lang);
		}
	}

	/**
	 * Sets the language used for localization.
	 * 
	 * @param newLanguage the new language to use
	 * for localizing Strings
	 */
	public void setLanguage(LANGUAGE newLanguage) {
		try {
			l10n = new PluginL10n(this, newLanguage);
		} catch (Exception e) {
			Logger.warning(this, "Could not set language to " + newLanguage);
		}
	}

	/**
	 * Reads an environment variable and parses it to a Freenet-supported
	 * language name. If the environment variable is not set, or cannot
	 * be correctly parsed to a language name, ENGLISH is returned by default.
	 * 
	 * @param envVar the environment variable to read
	 * @return the Language name of the parsed environment variable, or
	 * ENGLISH if there was an error.
	 */
	public LANGUAGE getLanguageFromEnvVar(String envVar) {
		String envVal = System.getenv(envVar);
		if (envVal != null && !envVal.isEmpty()) {
			envVal = envVal.split("-")[0];
		} else {
			envVal = "en";
		}
		LANGUAGE lang = LANGUAGE.mapToLanguage(envVal);
		if (lang == null) {
			lang = LANGUAGE.ENGLISH;
		}
		return lang;
	}

	public String getL10nFilesBasePath() {
		return L10nFilesBasePath;
	}

	public String getL10nFilesMask() {
		return "${lang}.properties";
	}

	public String getL10nOverrideFilesMask() {
		return "${lang}.override.properties";
	}

	public ClassLoader getPluginClassLoader() {
		return CENOL10n.class.getClassLoader();
	}

}