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
  35 import javax.swing.KeyStroke;
  36
  37 import net.pterodactylus.util.io.Closer;
  38
  39 /**
  40  * Class that handles i18n.
  41  *
  42  * @author David ‘Bombe’ Roden &lt;bombe@freenetproject.org&gt;
  43  * @version $Id$
  44  */
  45 public class I18n {
  46
  47         /** List of I18nables that are notified when the language changes. */
  48         private static final List<I18nable> i18nables = new ArrayList<I18nable>();
  49
  50         /** The current locale. */
  51         private static Locale currentLocale;
  52
  53         /** The default language. */
  54         private static Properties defaultLanguage;
  55
  56         /** The current language. */
  57         private static Properties currentLanguage;
  58
  59         static {
  60                 defaultLanguage = new Properties();
  61                 InputStream inputStream = null;
  62                 try {
  63                         inputStream = I18n.class.getResourceAsStream("jSite.properties");
  64                         if (inputStream != null) {
  65                                 defaultLanguage.load(inputStream);
  66                         }
  67                 } catch (IOException e) {
  68                         /* something is fucked. */
  69                 }
  70                 setLocale(Locale.getDefault(), false);
  71         }
  72
  73         /**
  74          * Returns the translated value for a key. The translated values may contain
  75          * placeholders that are replaced with the given parameters.
  76          *
  77          * @see MessageFormat
  78          * @param key
  79          *            The key to get
  80          * @param parameters
  81          *            The parameters in case the translated value contains
  82          *            placeholders
  83          * @return The translated message, or the key itself if no translation could
  84          *         be found
  85          */
  86         public static String get(String key, Object... parameters) {
  87                 String value = null;
  88                 value = currentLanguage.getProperty(key);
  89                 if (value == null) {
  90                         return key;
  91                 }
  92                 if ((parameters != null) && (parameters.length > 0)) {
  93                         return MessageFormat.format(value, parameters);
  94                 }
  95                 return value;
  96         }
  97
  98         /**
  99          * Returns the keycode from the value of the given key. You can specify the
 100          * constants in {@link KeyEvent} in the properties file, e.g. VK_S for the
 101          * keycode ‘s’ when used for mnemonics.
 102          *
 103          * @param key
 104          *            The key under which the keycode is stored
 105          * @return The keycode
 106          */
 107         public static int getKey(String key) {
 108                 String value = currentLanguage.getProperty(key);
 109                 if (value == null) {
 110                         return -1;
 111                 }
 112                 if (value.startsWith("VK_")) {
 113                         try {
 114                                 Field field = KeyEvent.class.getField(value);
 115                                 return field.getInt(null);
 116                         } catch (SecurityException e) {
 117                                 /* ignore. */
 118                         } catch (NoSuchFieldException e) {
 119                                 /* ignore. */
 120                         } catch (IllegalArgumentException e) {
 121                                 /* ignore. */
 122                         } catch (IllegalAccessException e) {
 123                                 /* ignore. */
 124                         }
 125                 }
 126                 return value.toUpperCase().charAt(0);
 127         }
 128
 129         /**
 130          * Returns a key stroke for use with swing accelerators.
 131          *
 132          * @param key
 133          *            The key of the key stroke
 134          * @return The key stroke, or <code>null</code> if no key stroke could be
 135          *         created from the translated value
 136          */
 137         public static KeyStroke getKeyStroke(String key) {
 138                 String value = currentLanguage.getProperty(key);
 139                 if (value == null) {
 140                         return null;
 141                 }
 142                 StringTokenizer keyTokens = new StringTokenizer(value, "+- ");
 143                 int modifierMask = 0;
 144                 while (keyTokens.hasMoreTokens()) {
 145                         String keyToken = keyTokens.nextToken();
 146                         if ("ctrl".equalsIgnoreCase(keyToken)) {
 147                                 modifierMask |= InputEvent.CTRL_DOWN_MASK;
 148                         } else if ("alt".equalsIgnoreCase(keyToken)) {
 149                                 modifierMask |= InputEvent.ALT_DOWN_MASK;
 150                         } else if ("shift".equalsIgnoreCase(keyToken)) {
 151                                 modifierMask |= InputEvent.SHIFT_DOWN_MASK;
 152                         } else {
 153                                 if (keyToken.startsWith("VK_")) {
 154                                         try {
 155                                                 Field field = KeyEvent.class.getField(keyToken);
 156                                                 return KeyStroke.getKeyStroke(field.getInt(null), modifierMask);
 157                                         } catch (SecurityException e) {
 158                                                 /* ignore. */
 159                                         } catch (NoSuchFieldException e) {
 160                                                 /* ignore. */
 161                                         } catch (IllegalArgumentException e) {
 162                                                 /* ignore. */
 163                                         } catch (IllegalAccessException e) {
 164                                                 /* ignore. */
 165                                         }
 166                                 }
 167                                 return KeyStroke.getKeyStroke(keyToken.charAt(0), modifierMask);
 168                         }
 169                 }
 170                 return null;
 171         }
 172
 173         /**
 174          * Sets the current locale.
 175          *
 176          * @param newLocale
 177          *            The new locale to use
 178          */
 179         public static void setLocale(Locale newLocale) {
 180                 setLocale(newLocale, true);
 181         }
 182
 183         /**
 184          * Sets the current locale.
 185          *
 186          * @param newLocale
 187          *            The new locale to use
 188          * @param notify
 189          *            <code>true</code> to notify registered {@link I18nable}s
 190          *            after the language was changed
 191          */
 192         private static void setLocale(Locale newLocale, boolean notify) {
 193                 currentLocale = newLocale;
 194                 InputStream inputStream = null;
 195                 try {
 196                         currentLanguage = new Properties(defaultLanguage);
 197                         if (newLocale == Locale.ENGLISH) {
 198                                 if (notify) {
 199                                         notifyI18nables();
 200                                 }
 201                                 return;
 202                         }
 203                         inputStream = I18n.class.getResourceAsStream("jSite_" + newLocale.getLanguage() + ".properties");
 204                         if (inputStream != null) {
 205                                 currentLanguage.load(inputStream);
 206                                 if (notify) {
 207                                         notifyI18nables();
 208                                 }
 209                         }
 210                 } catch (MissingResourceException mre1) {
 211                         currentLocale = Locale.ENGLISH;
 212                 } catch (IOException ioe1) {
 213                         currentLocale = Locale.ENGLISH;
 214                 } finally {
 215                         Closer.close(inputStream);
 216                 }
 217         }
 218
 219         /**
 220          * Returns the current locale.
 221          *
 222          * @return The current locale
 223          */
 224         public static Locale getLocale() {
 225                 return currentLocale;
 226         }
 227
 228         /**
 229          * Finds all available locales.
 230          *
 231          * @return All available locales
 232          */
 233         public static List<Locale> findAvailableLanguages() {
 234                 List<Locale> availableLanguages = new ArrayList<Locale>();
 235                 availableLanguages.add(Locale.ENGLISH);
 236                 availableLanguages.add(Locale.GERMAN);
 237                 return availableLanguages;
 238         }
 239
 240         /**
 241          * Registers the given I18nable to be updated when the language is changed.
 242          *
 243          * @param i18nable
 244          *            The i18nable to register
 245          */
 246         public static void registerI18nable(I18nable i18nable) {
 247                 i18nables.add(i18nable);
 248         }
 249
 250         /**
 251          * Deregisters the given I18nable to be updated when the language is
 252          * changed.
 253          *
 254          * @param i18nable
 255          *            The i18nable to register
 256          */
 257         public static void deregisterI18nable(I18nable i18nable) {
 258                 i18nables.remove(i18nable);
 259         }
 260
 261         //
 262         // PRIVATE METHODS
 263         //
 264
 265         /**
 266          * Notifies all registered {@link I18nable}s that the language was changed.
 267          */
 268         private static void notifyI18nables() {
 269                 for (I18nable i18nable: i18nables) {
 270                         i18nable.updateI18n();
 271                 }
 272         }
 273
 274 }