LanguageManager.java

/*
 * Created on 09-ene-2006
 * 
 * TODO To change the template for this generated file go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
package org.herac.tuxguitar.gui.system.language;

import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import org.apache.log4j.Logger;
import org.herac.tuxguitar.gui.editors.chord.ChordSelector;
import org.herac.tuxguitar.gui.util.TGFileUtils;

/**
 * @author julian
 * 
 */
public class LanguageManager {

  public static final String EXTENSION = ".properties";
  public static final String PACKAGE = "lang";
  public static final String PREFIX = "messages";

  private String[] languages;
  private List<LanguageLoader> loaders;
  private TGResourceBundle resources;

  public LanguageManager() {
    this.loaders = new ArrayList<LanguageLoader>();
    this.loadLanguages();
  }

  public void addLoader(LanguageLoader loader) {
    if (!this.loaders.contains(loader)) {
      this.loaders.add(loader);
    }
  }

  private void fireChanges() {
    for (final LanguageLoader loader : this.loaders) {
      loader.loadProperties();
    }
  }

  public String getLanguage() {
    if (this.resources != null) {
      Locale locale = this.resources.getLocale();
      boolean language = (locale.getLanguage() != null && locale.getLanguage()
          .length() > 0);
      boolean country = (locale.getCountry() != null && locale.getCountry()
          .length() > 0);
      boolean variant = (locale.getVariant() != null && locale.getVariant()
          .length() > 0);

      String localeId = new String();
      if (language) {
        localeId += locale.getLanguage();
      }
      if (country) {
        localeId += "_" + locale.getCountry();
      }
      if (variant) {
        localeId += "_"
            + (country ? locale.getVariant() : ("_" + locale.getVariant()));
      }
      return localeId;
    }
    return null;
  }

  public String[] getLanguages() {
    return this.languages;
  }

  private Locale getLocale(String lang) {
    if (this.isSupportedLanguage(lang)) {
      String[] locale = lang.split("_");
      String language = (locale.length > 0 ? locale[0] : "");
      String country = (locale.length > 1 ? locale[1] : "");
      String variant = (locale.length > 2 ? locale[2] : "");
      return new Locale(language, country, variant);
    }
    return Locale.getDefault();
  }

  public String getProperty(String key) {
    return this.getProperty(key, key);
  }

  public String getProperty(String key, Object[] arguments) {
    return getProperty(key, key, arguments);
  }

  public String getProperty(String key, String value) {
    try {
      String property = this.resources.getString(key);
      return (property == null ? value : property);
    } catch (Throwable throwable) {
      return value;
    }
  }

  public String getProperty(String key, String value, Object[] arguments) {
    String property = this.getProperty(key, value);
    return (arguments != null ? MessageFormat.format(property, arguments)
        : property);
  }

  private boolean isSupportedLanguage(String lang) {
    if (lang != null && lang.length() > 0 && this.languages != null) {
      for (int i = 0; i < this.languages.length; i++) {
        if (this.languages[i].equals(lang)) {
          return true;
        }
      }
    }
    return false;
  }

  /**
   * Load language files from lang folder
   * 
   */
  private void loadLanguages() {
    List<String> availableList = new ArrayList<String>();
    String[] fileNames = TGFileUtils.getFileNames("lang");
    if (fileNames != null) {
      // now iterate over them
      for (int i = 0; i < fileNames.length; i++) {
        if (fileNames[i].indexOf("messages_") == 0) {
          int prefixIndex = fileNames[i].indexOf(PREFIX + "_");
          int extensionIndex = fileNames[i].indexOf(EXTENSION);
          if (prefixIndex == 0 && extensionIndex > (PREFIX + "_").length()) {
            availableList.add(fileNames[i].substring((PREFIX + "_").length(),
                extensionIndex));
          }
        }
      }
    }
    this.languages = new String[availableList.size()];
    for (int i = 0; i < this.languages.length; i++) {
      this.languages[i] = (String) availableList.get(i);
    }
  }

  public void removeLoader(LanguageLoader loader) {
    if (this.loaders.contains(loader)) {
      this.loaders.remove(loader);
    }
  }

  /** The Logger for this class. */
  public static final transient Logger LOG = Logger
      .getLogger(LanguageManager.class);
  
  public void setLanguage(String lang) {
    try {
      String baseName = (PACKAGE + "." + PREFIX);
      Locale locale = getLocale(lang);
      this.resources = TGResourceBundle.getBundle(baseName, locale);
      this.fireChanges();
    } catch (Exception e) {
      LOG.error(e);
    }
  }
}