Source for javax.swing.text.InternationalFormatter

   1: /* InternationalFormatter.java --
   2: Copyright (C) 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package javax.swing.text;
  39: 
  40: import java.text.AttributedCharacterIterator;
  41: import java.text.Format;
  42: import java.text.ParseException;
  43: import java.util.Iterator;
  44: import java.util.Map;
  45: import java.util.Set;
  46: 
  47: import javax.swing.Action;
  48: import javax.swing.JFormattedTextField;
  49: 
  50: /**
  51:  * This extends {@link DefaultFormatter} so that the value to string
  52:  * conversion is done via a {@link Format} object. This allows
  53:  * various additional formats to be handled by JFormattedField.
  54:  *
  55:  * @author Roman Kennke (roman@kennke.org)
  56:  */
  57: public class InternationalFormatter
  58:   extends DefaultFormatter
  59: {
  60:   /** The serialization UID (compatible with JDK1.5). */
  61:   private static final long serialVersionUID = 2436068675711756856L;
  62: 
  63:   /** The format that handles value to string conversion. */
  64:   Format format;
  65: 
  66:   /** The minimal permissable value. */
  67:   Comparable minimum;
  68: 
  69:   /** The maximal permissable value. */
  70:   Comparable maximum;
  71: 
  72:   /**
  73:    * Creates a new InternationalFormatter with no Format specified.
  74:    */
  75:   public InternationalFormatter()
  76:   {
  77:     super();
  78:     minimum = null;
  79:     maximum = null;
  80:     format = null;
  81:   }
  82: 
  83:   /**
  84:    * Creates a new InternationalFormatter that uses the specified
  85:    * Format object for value to string conversion.
  86:    *
  87:    * @param format the Format object to use for value to string conversion
  88:    */
  89:   public InternationalFormatter(Format format)
  90:   {
  91:     this();
  92:     setFormat(format);
  93:   }
  94: 
  95:   /**
  96:    * Sets the Format object that is used to convert values to strings.
  97:    *
  98:    * @param format the Format to use for value to string conversion
  99:    *
 100:    * @see Format
 101:    */
 102:   public void setFormat(Format format)
 103:   {
 104:     this.format = format;
 105:   }
 106: 
 107:   /**
 108:    * Returns the currently used Format object that is used to format
 109:    * the JFormattedField.
 110:    *
 111:    * @return the current Format
 112:    */
 113:   public Format getFormat()
 114:   {
 115:     return format;
 116:   }
 117: 
 118:   /**
 119:    * Sets the minimum value that is allowed by this Formatter. The minimum
 120:    * value is given as an object that implements the {@link Comparable}
 121:    * interface.
 122:    *
 123:    * If <code>minValue</code> is null, then the Formatter has no restrictions
 124:    * at the lower end.
 125:    *
 126:    * If value class is not yet specified and <code>minValue</code> is not
 127:    * null, then <code>valueClass</code> is set to the class of the minimum
 128:    * value.
 129:    *
 130:    * @param minValue the minimum permissable value
 131:    *
 132:    * @see Comparable
 133:    */
 134:   public void setMinimum(Comparable minValue)
 135:   {
 136:     minimum = minValue;
 137:     if (valueClass == null && minValue != null)
 138:       valueClass = minValue.getClass();
 139:   }
 140: 
 141:   /**
 142:    * Returns the minimal value that is allowed by this Formatter.
 143:    *
 144:    * A <code>null</code> value means that there is no restriction.
 145:    *
 146:    * @return the minimal value that is allowed by this Formatter or
 147:    *     <code>null</code> if there is no restriction
 148:    */
 149:   public Comparable getMinimum()
 150:   {
 151:     return minimum;
 152:   }
 153: 
 154:   /**
 155:    * Sets the maximum value that is allowed by this Formatter. The maximum
 156:    * value is given as an object that implements the {@link Comparable}
 157:    * interface.
 158:    *
 159:    * If <code>maxValue</code> is null, then the Formatter has no restrictions
 160:    * at the upper end.
 161:    *
 162:    * If value class is not yet specified and <code>maxValue</code> is not
 163:    * null, then <code>valueClass</code> is set to the class of the maximum
 164:    * value.
 165:    *
 166:    * @param maxValue the maximum permissable value
 167:    *
 168:    * @see Comparable
 169:    */
 170:   public void setMaximum(Comparable maxValue)
 171:   {
 172:     maximum = maxValue;
 173:     if (valueClass == null && maxValue != null)
 174:       valueClass = maxValue.getClass();
 175:   }
 176: 
 177:   /**
 178:    * Returns the maximal value that is allowed by this Formatter.
 179:    *
 180:    * A <code>null</code> value means that there is no restriction.
 181:    *
 182:    * @return the maximal value that is allowed by this Formatter or
 183:    *     <code>null</code> if there is no restriction
 184:    */
 185:   public Comparable getMaximum()
 186:   {
 187:     return maximum;
 188:   }
 189: 
 190:   /**
 191:    * Installs the formatter on the specified {@link JFormattedTextField}.
 192:    *
 193:    * This method does the following things:
 194:    * <ul>
 195:    * <li>Display the value of #valueToString in the
 196:    *  <code>JFormattedTextField</code></li>
 197:    * <li>Install the Actions from #getActions on the <code>JTextField</code>
 198:    * </li>
 199:    * <li>Install the DocumentFilter returned by #getDocumentFilter</li>
 200:    * <li>Install the NavigationFilter returned by #getNavigationFilter</li>
 201:    * </ul>
 202:    *
 203:    * This method is typically not overridden by subclasses. Instead override
 204:    * one of the mentioned methods in order to customize behaviour.
 205:    *
 206:    * @param ftf the {@link JFormattedTextField} in which this formatter
 207:    *     is installed 
 208:    */
 209:   public void install(JFormattedTextField ftf)
 210:   {
 211:     super.install(ftf);
 212:   }
 213: 
 214:   /**
 215:    * Converts a value object into a String. This is done by invoking
 216:    * {@link Format#format(Object)} on the specified <code>Format</code> object.
 217:    * If no format is set, then {@link DefaultFormatter#valueToString(Object)}
 218:    * is called as a fallback.
 219:    *
 220:    * @param value the value to be converted
 221:    *
 222:    * @return the string representation of the value
 223:    *
 224:    * @throws ParseException if the value cannot be converted
 225:    */
 226:   public String valueToString(Object value)
 227:     throws ParseException
 228:   {
 229:     if (format != null)
 230:       return format.format(value);
 231:     else
 232:       return super.valueToString(value);
 233:   }
 234: 
 235:   /**
 236:    * Converts a String (from the JFormattedTextField input) to a value.
 237:    * This is achieved by invoking {@link Format#parseObject(String)} on
 238:    * the specified <code>Format</code> object.
 239:    *
 240:    * This implementation differs slightly from {@link DefaultFormatter},
 241:    * it does:
 242:    * <ol>
 243:    * <li>Convert the string to an <code>Object</code> using the
 244:    *   <code>Formatter</code>.</li>
 245:    * <li>If a <code>valueClass</code> has been set, this object is passed to
 246:    *   {@link DefaultFormatter#stringToValue(String)} so that the value
 247:    *   has the correct type. This may or may not work correctly, depending on
 248:    *   the implementation of toString() in the value class and if the class
 249:    *   implements a constructor that takes one String as argument.</li>
 250:    * <li>If no {@link ParseException} has been thrown so far, we check if the
 251:    *   value exceeds either <code>minimum</code> or <code>maximum</code> if
 252:    *   one of those has been specified and throw a <code>ParseException</code>
 253:    *   if it does.</li>
 254:    * <li>Return the value.</li>
 255:    * </ol>
 256:    *
 257:    * If no format has been specified, then
 258:    * {@link DefaultFormatter#stringToValue(String)} is invoked as fallback.
 259:    *
 260:    * @param string the string to convert
 261:    *
 262:    * @return the value for the string
 263:    *
 264:    * @throws ParseException if the string cannot be converted into
 265:    *     a value object (e.g. invalid input)
 266:    */
 267:   public Object stringToValue(String string)
 268:     throws ParseException
 269:   {
 270:     if (format != null)
 271:       {
 272:         Object o = format.parseObject(string);
 273: 
 274:         // If a value class has been set, call super in order to get
 275:         // the class right. That is what the JDK API docs suggest, so we do
 276:         // it that way.
 277:         if (valueClass != null)
 278:           o = super.stringToValue(o.toString());
 279: 
 280:         // Check for minimum and maximum bounds
 281:         if (minimum != null && minimum.compareTo(o) > 0)
 282:           throw new ParseException("The value may not be less than the"
 283:                                     + " specified minimum", 0);
 284:         if (maximum != null && minimum.compareTo(o) < 0)
 285:           throw new ParseException("The value may not be greater than the"
 286:                                     + " specified maximum", 0);
 287:         return o;
 288:       }
 289:     else
 290:       return super.stringToValue(string);
 291:   }
 292: 
 293:   /**
 294:    * Returns the {@link Format.Field} constants that are associated with
 295:    * the specified position in the text.
 296:    *
 297:    * If <code>offset</code> is not a valid location in the input field,
 298:    * an empty array of fields is returned.
 299:    *
 300:    * @param offset the position in the text from which we want to fetch
 301:    *     the fields constants
 302:    *
 303:    * @return the field values associated with the specified position in
 304:    *     the text
 305:    */
 306:   public Format.Field[] getFields(int offset)
 307:   {
 308:     // TODO: don't know if this is correct
 309:     AttributedCharacterIterator aci = format.formatToCharacterIterator
 310:                                          (getFormattedTextField().getValue());
 311:     aci.setIndex(offset);
 312:     Map atts = aci.getAttributes();
 313:     Set keys = atts.keySet();
 314:     Format.Field[] fields = new Format.Field[keys.size()];
 315:     int index = 0;
 316:     for (Iterator i = keys.iterator(); i.hasNext(); index++)
 317:       fields[index] = (Format.Field) i.next();
 318:     return fields;
 319:   }
 320: 
 321:   /**
 322:    * This creates and returns a clone of this Formatter.
 323:    *
 324:    * @return a clone of this formatter
 325:    *
 326:    * @throws CloneNotSupportedException not thrown here, since cloning is
 327:    *     supported
 328:    * XXX - FIXME - Whole method disabled as workaround for gcj bug #22060.
 329:   public Object clone()
 330:     throws CloneNotSupportedException
 331:   {
 332:     // TODO: it has to be considered, if we should return a deep or shallow
 333:     // clone here. for now we return a shallow clone
 334:     Object clone = super.clone();
 335:     return clone;
 336:   }
 337:    */
 338: 
 339:   /**
 340:    * Returns the Actions that are supported by this Formatter.
 341:    *
 342:    * @specnote the JDK API docs say here: <cite>If
 343:    *     <code>getSupportsIncrement</code> returns true, this returns two
 344:    *     Actions suitable for incrementing/decrementing the value.</cite>
 345:    *     The questsion is, which method <code>getSupportsIncrement</code>?
 346:    *     There is no such method in the whole API! So we just call
 347:    *     super.getActions here.
 348:    */
 349:   public Action[] getActions()
 350:   {
 351:     return super.getActions();
 352:   }
 353: }