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                         System.err.println("please fix “" + key + "”!");
  91                         return null;
  92                 }
  93                 if ((parameters != null) && (parameters.length > 0)) {
  94                         return MessageFormat.format(value, parameters);
  95                 }
  96                 return value;
  97         }
  98
  99         /**
 100          * Returns the keycode from the value of the given key. You can specify the
 101          * constants in {@link KeyEvent} in the properties file, e.g. VK_S for the
 102          * keycode ‘s’ when used for mnemonics.
 103          *
 104          * @param key
 105          *            The key under which the keycode is stored
 106          * @return The keycode
 107          */
 108         public static int getKey(String key) {
 109                 String value = currentLanguage.getProperty(key);
 110                 if ((value != null) && value.startsWith("VK_")) {
 111                         try {
 112                                 Field field = KeyEvent.class.getField(value);
 113                                 return field.getInt(null);
 114                         } catch (SecurityException e) {
 115                                 /* ignore. */
 116                         } catch (NoSuchFieldException e) {
 117                                 /* ignore. */
 118                         } catch (IllegalArgumentException e) {
 119                                 /* ignore. */
 120                         } catch (IllegalAccessException e) {
 121                                 /* ignore. */
 122                         }
 123                 }
 124                 System.err.println("please fix “" + key + "”!");
 125                 return KeyEvent.VK_UNDEFINED;
 126         }
 127
 128         /**
 129          * Returns a key stroke for use with swing accelerators.
 130          *
 131          * @param key
 132          *            The key of the key stroke
 133          * @return The key stroke, or <code>null</code> if no key stroke could be
 134          *         created from the translated value
 135          */
 136         public static KeyStroke getKeyStroke(String key) {
 137                 String value = currentLanguage.getProperty(key);
 138                 if (value == null) {
 139                         return null;
 140                 }
 141                 StringTokenizer keyTokens = new StringTokenizer(value, "+- ");
 142                 int modifierMask = 0;
 143                 while (keyTokens.hasMoreTokens()) {
 144                         String keyToken = keyTokens.nextToken();
 145                         if ("ctrl".equalsIgnoreCase(keyToken)) {
 146                                 modifierMask |= InputEvent.CTRL_DOWN_MASK;
 147                         } else if ("alt".equalsIgnoreCase(keyToken)) {
 148                                 modifierMask |= InputEvent.ALT_DOWN_MASK;
 149                         } else if ("shift".equalsIgnoreCase(keyToken)) {
 150                                 modifierMask |= InputEvent.SHIFT_DOWN_MASK;
 151                         } else {
 152                                 if (keyToken.startsWith("VK_")) {
 153                                         try {
 154                                                 Field field = KeyEvent.class.getField(keyToken);
 155                                                 return KeyStroke.getKeyStroke(field.getInt(null), modifierMask);
 156                                         } catch (SecurityException e) {
 157                                                 /* ignore. */
 158                                         } catch (NoSuchFieldException e) {
 159                                                 /* ignore. */
 160                                         } catch (IllegalArgumentException e) {
 161                                                 /* ignore. */
 162                                         } catch (IllegalAccessException e) {
 163                                                 /* ignore. */
 164                                         }
 165                                 }
 166                                 return KeyStroke.getKeyStroke(keyToken.charAt(0), modifierMask);
 167                         }
 168                 }
 169                 return null;
 170         }
 171
 172         /**
 173          * Sets the current locale.
 174          *
 175          * @param newLocale
 176          *            The new locale to use
 177          */
 178         public static void setLocale(Locale newLocale) {
 179                 setLocale(newLocale, true);
 180         }
 181
 182         /**
 183          * Sets the current locale.
 184          *
 185          * @param newLocale
 186          *            The new locale to use
 187          * @param notify
 188          *            <code>true</code> to notify registered {@link I18nable}s
 189          *            after the language was changed
 190          */
 191         private static void setLocale(Locale newLocale, boolean notify) {
 192                 currentLocale = newLocale;
 193                 InputStream inputStream = null;
 194                 try {
 195                         currentLanguage = new Properties(defaultLanguage);
 196                         if (newLocale == Locale.ENGLISH) {
 197                                 if (notify) {
 198                                         notifyI18nables();
 199                                 }
 200                                 return;
 201                         }
 202                         inputStream = I18n.class.getResourceAsStream("jSite_" + newLocale.getLanguage() + ".properties");
 203                         if (inputStream != null) {
 204                                 currentLanguage.load(inputStream);
 205                                 if (notify) {
 206                                         notifyI18nables();
 207                                 }
 208                         }
 209                 } catch (MissingResourceException mre1) {
 210                         currentLocale = Locale.ENGLISH;
 211                 } catch (IOException ioe1) {
 212                         currentLocale = Locale.ENGLISH;
 213                 } finally {
 214                         Closer.close(inputStream);
 215                 }
 216         }
 217
 218         /**
 219          * Returns the current locale.
 220          *
 221          * @return The current locale
 222          */
 223         public static Locale getLocale() {
 224                 return currentLocale;
 225         }
 226
 227         /**
 228          * Finds all available locales.
 229          *
 230          * @return All available locales
 231          */
 232         public static List<Locale> findAvailableLanguages() {
 233                 List<Locale> availableLanguages = new ArrayList<Locale>();
 234                 availableLanguages.add(Locale.ENGLISH);
 235                 availableLanguages.add(Locale.GERMAN);
 236                 return availableLanguages;
 237         }
 238
 239         /**
 240          * Registers the given I18nable to be updated when the language is changed.
 241          *
 242          * @param i18nable
 243          *            The i18nable to register
 244          */
 245         public static void registerI18nable(I18nable i18nable) {
 246                 i18nables.add(i18nable);
 247         }
 248
 249         /**
 250          * Deregisters the given I18nable to be updated when the language is
 251          * changed.
 252          *
 253          * @param i18nable
 254          *            The i18nable to register
 255          */
 256         public static void deregisterI18nable(I18nable i18nable) {
 257                 i18nables.remove(i18nable);
 258         }
 259
 260         //
 261         // PRIVATE METHODS
 262         //
 263
 264         /**
 265          * Notifies all registered {@link I18nable}s that the language was changed.
 266          */
 267         private static void notifyI18nables() {
 268                 for (I18nable i18nable: i18nables) {
 269                         i18nable.updateI18n();
 270                 }
 271         }
 272
 273 }