I18n.java

   1 /*
   2  * jSite2 - I18n.java -
   3  * Copyright © 2008 David Roden
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18  */
  19
  20 package net.pterodactylus.jsite.i18n;
  21
  22 import java.awt.event.InputEvent;
  23 import java.awt.event.KeyEvent;
  24 import java.io.IOException;
  25 import java.io.InputStream;
  26 import java.lang.reflect.Field;
  27 import java.text.MessageFormat;
  28 import java.util.ArrayList;
  29 import java.util.List;
  30 import java.util.Locale;
  31 import java.util.MissingResourceException;
  32 import java.util.Properties;
  33 import java.util.StringTokenizer;
  34 import java.util.logging.Level;
  35 import java.util.logging.Logger;
  36
  37 import javax.swing.KeyStroke;
  38
  39 import net.pterodactylus.util.io.Closer;
  40 import net.pterodactylus.util.logging.Logging;
  41
  42 /**
  43  * Class that handles i18n.
  44  *
  45  * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
  46  */
  47 public class I18n {
  48
  49         /** Logger. */
  50         private static final Logger logger = Logging.getLogger(I18n.class.getName());
  51
  52         /** List of I18nables that are notified when the language changes. */
  53         private static final List<I18nable> i18nables = new ArrayList<I18nable>();
  54
  55         /** The current locale. */
  56         private static Locale currentLocale;
  57
  58         /** The default language. */
  59         private static Properties defaultLanguage;
  60
  61         /** The current language. */
  62         private static Properties currentLanguage;
  63
  64         static {
  65                 defaultLanguage = new Properties();
  66                 InputStream inputStream = null;
  67                 try {
  68                         inputStream = I18n.class.getResourceAsStream("jSite.properties");
  69                         if (inputStream != null) {
  70                                 defaultLanguage.load(inputStream);
  71                         }
  72                 } catch (IOException e) {
  73                         /* something is fucked. */
  74                 }
  75                 setLocale(Locale.getDefault(), false);
  76         }
  77
  78         /**
  79          * Returns the translated value for a key. The translated values may contain
  80          * placeholders that are replaced with the given parameters.
  81          *
  82          * @see MessageFormat
  83          * @param key
  84          *            The key to get
  85          * @param parameters
  86          *            The parameters in case the translated value contains
  87          *            placeholders
  88          * @return The translated message, or the key itself if no translation could
  89          *         be found
  90          */
  91         public static String get(String key, Object... parameters) {
  92                 String value = null;
  93                 value = currentLanguage.getProperty(key);
  94                 if (value == null) {
  95                         logger.log(Level.WARNING, "please fix “" + key + "”!", new Throwable());
  96                         /* TODO - replace with value when done! */
  97                         return null;
  98                 }
  99                 if ((parameters != null) && (parameters.length > 0)) {
 100                         return MessageFormat.format(value, parameters);
 101                 }
 102                 return value;
 103         }
 104
 105         /**
 106          * Returns the keycode from the value of the given key. You can specify the
 107          * constants in {@link KeyEvent} in the properties file, e.g. VK_S for the
 108          * keycode ‘s’ when used for mnemonics.
 109          *
 110          * @param key
 111          *            The key under which the keycode is stored
 112          * @return The keycode
 113          */
 114         public static int getKey(String key) {
 115                 String value = currentLanguage.getProperty(key);
 116                 if ((value != null) && value.startsWith("VK_")) {
 117                         try {
 118                                 Field field = KeyEvent.class.getField(value);
 119                                 return field.getInt(null);
 120                         } catch (SecurityException e) {
 121                                 /* ignore. */
 122                         } catch (NoSuchFieldException e) {
 123                                 /* ignore. */
 124                         } catch (IllegalArgumentException e) {
 125                                 /* ignore. */
 126                         } catch (IllegalAccessException e) {
 127                                 /* ignore. */
 128                         }
 129                 }
 130                 System.err.println("please fix “" + key + "”!");
 131                 return KeyEvent.VK_UNDEFINED;
 132         }
 133
 134         /**
 135          * Returns a key stroke for use with swing accelerators.
 136          *
 137          * @param key
 138          *            The key of the key stroke
 139          * @return The key stroke, or <code>null</code> if no key stroke could be
 140          *         created from the translated value
 141          */
 142         public static KeyStroke getKeyStroke(String key) {
 143                 String value = currentLanguage.getProperty(key);
 144                 if (value == null) {
 145                         return null;
 146                 }
 147                 StringTokenizer keyTokens = new StringTokenizer(value, "+- ");
 148                 int modifierMask = 0;
 149                 while (keyTokens.hasMoreTokens()) {
 150                         String keyToken = keyTokens.nextToken();
 151                         if ("ctrl".equalsIgnoreCase(keyToken)) {
 152                                 modifierMask |= InputEvent.CTRL_DOWN_MASK;
 153                         } else if ("alt".equalsIgnoreCase(keyToken)) {
 154                                 modifierMask |= InputEvent.ALT_DOWN_MASK;
 155                         } else if ("shift".equalsIgnoreCase(keyToken)) {
 156                                 modifierMask |= InputEvent.SHIFT_DOWN_MASK;
 157                         } else {
 158                                 if (keyToken.startsWith("VK_")) {
 159                                         if (keyToken.equals("VK_UNDEFINED")) {
 160                                                 return null;
 161                                         }
 162                                         try {
 163                                                 Field field = KeyEvent.class.getField(keyToken);
 164                                                 return KeyStroke.getKeyStroke(field.getInt(null), modifierMask);
 165                                         } catch (SecurityException e) {
 166                                                 /* ignore. */
 167                                         } catch (NoSuchFieldException e) {
 168                                                 /* ignore. */
 169                                         } catch (IllegalArgumentException e) {
 170                                                 /* ignore. */
 171                                         } catch (IllegalAccessException e) {
 172                                                 /* ignore. */
 173                                         }
 174                                 }
 175                                 return KeyStroke.getKeyStroke(keyToken.charAt(0), modifierMask);
 176                         }
 177                 }
 178                 return null;
 179         }
 180
 181         /**
 182          * Sets the current locale.
 183          *
 184          * @param newLocale
 185          *            The new locale to use
 186          */
 187         public static void setLocale(Locale newLocale) {
 188                 setLocale(newLocale, true);
 189         }
 190
 191         /**
 192          * Sets the current locale.
 193          *
 194          * @param newLocale
 195          *            The new locale to use
 196          * @param notify
 197          *            <code>true</code> to notify registered {@link I18nable}s
 198          *            after the language was changed
 199          */
 200         private static void setLocale(Locale newLocale, boolean notify) {
 201                 currentLocale = newLocale;
 202                 InputStream inputStream = null;
 203                 try {
 204                         currentLanguage = new Properties(defaultLanguage);
 205                         if (newLocale == Locale.ENGLISH) {
 206                                 if (notify) {
 207                                         notifyI18nables();
 208                                 }
 209                                 return;
 210                         }
 211                         inputStream = I18n.class.getResourceAsStream("jSite_" + newLocale.getLanguage() + ".properties");
 212                         if (inputStream != null) {
 213                                 currentLanguage.load(inputStream);
 214                                 if (notify) {
 215                                         notifyI18nables();
 216                                 }
 217                         }
 218                 } catch (MissingResourceException mre1) {
 219                         currentLocale = Locale.ENGLISH;
 220                 } catch (IOException ioe1) {
 221                         currentLocale = Locale.ENGLISH;
 222                 } finally {
 223                         Closer.close(inputStream);
 224                 }
 225         }
 226
 227         /**
 228          * Returns the current locale.
 229          *
 230          * @return The current locale
 231          */
 232         public static Locale getLocale() {
 233                 return currentLocale;
 234         }
 235
 236         /**
 237          * Finds all available locales.
 238          *
 239          * @return All available locales
 240          */
 241         public static List<Locale> findAvailableLanguages() {
 242                 List<Locale> availableLanguages = new ArrayList<Locale>();
 243                 availableLanguages.add(Locale.ENGLISH);
 244                 availableLanguages.add(Locale.GERMAN);
 245                 return availableLanguages;
 246         }
 247
 248         /**
 249          * Registers the given I18nable to be updated when the language is changed.
 250          *
 251          * @param i18nable
 252          *            The i18nable to register
 253          */
 254         public static void registerI18nable(I18nable i18nable) {
 255                 i18nables.add(i18nable);
 256         }
 257
 258         /**
 259          * Deregisters the given I18nable to be updated when the language is
 260          * changed.
 261          *
 262          * @param i18nable
 263          *            The i18nable to register
 264          */
 265         public static void deregisterI18nable(I18nable i18nable) {
 266                 i18nables.remove(i18nable);
 267         }
 268
 269         //
 270         // PRIVATE METHODS
 271         //
 272
 273         /**
 274          * Notifies all registered {@link I18nable}s that the language was changed.
 275          */
 276         private static void notifyI18nables() {
 277                 for (I18nable i18nable: i18nables) {
 278                         i18nable.updateI18n();
 279                 }
 280         }
 281
 282 }