src/net/pterodactylus/jsite/i18n/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  * @version $Id$
  47  */
  48 public class I18n {
  49
  50         /** Logger. */
  51         private static final Logger logger = Logging.getLogger(I18n.class.getName());
  52
  53         /** List of I18nables that are notified when the language changes. */
  54         private static final List<I18nable> i18nables = new ArrayList<I18nable>();
  55
  56         /** The current locale. */
  57         private static Locale currentLocale;
  58
  59         /** The default language. */
  60         private static Properties defaultLanguage;
  61
  62         /** The current language. */
  63         private static Properties currentLanguage;
  64
  65         static {
  66                 defaultLanguage = new Properties();
  67                 InputStream inputStream = null;
  68                 try {
  69                         inputStream = I18n.class.getResourceAsStream("jSite.properties");
  70                         if (inputStream != null) {
  71                                 defaultLanguage.load(inputStream);
  72                         }
  73                 } catch (IOException e) {
  74                         /* something is fucked. */
  75                 }
  76                 setLocale(Locale.getDefault(), false);
  77         }
  78
  79         /**
  80          * Returns the translated value for a key. The translated values may contain
  81          * placeholders that are replaced with the given parameters.
  82          *
  83          * @see MessageFormat
  84          * @param key
  85          *            The key to get
  86          * @param parameters
  87          *            The parameters in case the translated value contains
  88          *            placeholders
  89          * @return The translated message, or the key itself if no translation could
  90          *         be found
  91          */
  92         public static String get(String key, Object... parameters) {
  93                 String value = null;
  94                 value = currentLanguage.getProperty(key);
  95                 if (value == null) {
  96                         logger.log(Level.WARNING, "please fix “" + key + "”!", new Throwable());
  97                         /* TODO - replace with value when done! */
  98                         return null;
  99                 }
 100                 if ((parameters != null) && (parameters.length > 0)) {
 101                         return MessageFormat.format(value, parameters);
 102                 }
 103                 return value;
 104         }
 105
 106         /**
 107          * Returns the keycode from the value of the given key. You can specify the
 108          * constants in {@link KeyEvent} in the properties file, e.g. VK_S for the
 109          * keycode ‘s’ when used for mnemonics.
 110          *
 111          * @param key
 112          *            The key under which the keycode is stored
 113          * @return The keycode
 114          */
 115         public static int getKey(String key) {
 116                 String value = currentLanguage.getProperty(key);
 117                 if ((value != null) && value.startsWith("VK_")) {
 118                         try {
 119                                 Field field = KeyEvent.class.getField(value);
 120                                 return field.getInt(null);
 121                         } catch (SecurityException e) {
 122                                 /* ignore. */
 123                         } catch (NoSuchFieldException e) {
 124                                 /* ignore. */
 125                         } catch (IllegalArgumentException e) {
 126                                 /* ignore. */
 127                         } catch (IllegalAccessException e) {
 128                                 /* ignore. */
 129                         }
 130                 }
 131                 System.err.println("please fix “" + key + "”!");
 132                 return KeyEvent.VK_UNDEFINED;
 133         }
 134
 135         /**
 136          * Returns a key stroke for use with swing accelerators.
 137          *
 138          * @param key
 139          *            The key of the key stroke
 140          * @return The key stroke, or <code>null</code> if no key stroke could be
 141          *         created from the translated value
 142          */
 143         public static KeyStroke getKeyStroke(String key) {
 144                 String value = currentLanguage.getProperty(key);
 145                 if (value == null) {
 146                         return null;
 147                 }
 148                 StringTokenizer keyTokens = new StringTokenizer(value, "+- ");
 149                 int modifierMask = 0;
 150                 while (keyTokens.hasMoreTokens()) {
 151                         String keyToken = keyTokens.nextToken();
 152                         if ("ctrl".equalsIgnoreCase(keyToken)) {
 153                                 modifierMask |= InputEvent.CTRL_DOWN_MASK;
 154                         } else if ("alt".equalsIgnoreCase(keyToken)) {
 155                                 modifierMask |= InputEvent.ALT_DOWN_MASK;
 156                         } else if ("shift".equalsIgnoreCase(keyToken)) {
 157                                 modifierMask |= InputEvent.SHIFT_DOWN_MASK;
 158                         } else {
 159                                 if (keyToken.startsWith("VK_")) {
 160                                         if (keyToken.equals("VK_UNDEFINED")) {
 161                                                 return null;
 162                                         }
 163                                         try {
 164                                                 Field field = KeyEvent.class.getField(keyToken);
 165                                                 return KeyStroke.getKeyStroke(field.getInt(null), modifierMask);
 166                                         } catch (SecurityException e) {
 167                                                 /* ignore. */
 168                                         } catch (NoSuchFieldException e) {
 169                                                 /* ignore. */
 170                                         } catch (IllegalArgumentException e) {
 171                                                 /* ignore. */
 172                                         } catch (IllegalAccessException e) {
 173                                                 /* ignore. */
 174                                         }
 175                                 }
 176                                 return KeyStroke.getKeyStroke(keyToken.charAt(0), modifierMask);
 177                         }
 178                 }
 179                 return null;
 180         }
 181
 182         /**
 183          * Sets the current locale.
 184          *
 185          * @param newLocale
 186          *            The new locale to use
 187          */
 188         public static void setLocale(Locale newLocale) {
 189                 setLocale(newLocale, true);
 190         }
 191
 192         /**
 193          * Sets the current locale.
 194          *
 195          * @param newLocale
 196          *            The new locale to use
 197          * @param notify
 198          *            <code>true</code> to notify registered {@link I18nable}s
 199          *            after the language was changed
 200          */
 201         private static void setLocale(Locale newLocale, boolean notify) {
 202                 currentLocale = newLocale;
 203                 InputStream inputStream = null;
 204                 try {
 205                         currentLanguage = new Properties(defaultLanguage);
 206                         if (newLocale == Locale.ENGLISH) {
 207                                 if (notify) {
 208                                         notifyI18nables();
 209                                 }
 210                                 return;
 211                         }
 212                         inputStream = I18n.class.getResourceAsStream("jSite_" + newLocale.getLanguage() + ".properties");
 213                         if (inputStream != null) {
 214                                 currentLanguage.load(inputStream);
 215                                 if (notify) {
 216                                         notifyI18nables();
 217                                 }
 218                         }
 219                 } catch (MissingResourceException mre1) {
 220                         currentLocale = Locale.ENGLISH;
 221                 } catch (IOException ioe1) {
 222                         currentLocale = Locale.ENGLISH;
 223                 } finally {
 224                         Closer.close(inputStream);
 225                 }
 226         }
 227
 228         /**
 229          * Returns the current locale.
 230          *
 231          * @return The current locale
 232          */
 233         public static Locale getLocale() {
 234                 return currentLocale;
 235         }
 236
 237         /**
 238          * Finds all available locales.
 239          *
 240          * @return All available locales
 241          */
 242         public static List<Locale> findAvailableLanguages() {
 243                 List<Locale> availableLanguages = new ArrayList<Locale>();
 244                 availableLanguages.add(Locale.ENGLISH);
 245                 availableLanguages.add(Locale.GERMAN);
 246                 return availableLanguages;
 247         }
 248
 249         /**
 250          * Registers the given I18nable to be updated when the language is changed.
 251          *
 252          * @param i18nable
 253          *            The i18nable to register
 254          */
 255         public static void registerI18nable(I18nable i18nable) {
 256                 i18nables.add(i18nable);
 257         }
 258
 259         /**
 260          * Deregisters the given I18nable to be updated when the language is
 261          * changed.
 262          *
 263          * @param i18nable
 264          *            The i18nable to register
 265          */
 266         public static void deregisterI18nable(I18nable i18nable) {
 267                 i18nables.remove(i18nable);
 268         }
 269
 270         //
 271         // PRIVATE METHODS
 272         //
 273
 274         /**
 275          * Notifies all registered {@link I18nable}s that the language was changed.
 276          */
 277         private static void notifyI18nables() {
 278                 for (I18nable i18nable: i18nables) {
 279                         i18nable.updateI18n();
 280                 }
 281         }
 282
 283 }