Source for javax.swing.text.InternationalFormatter

   1: /* InternationalFormatter.java --
   2: Copyright (C) 2005, 2006  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:     setCommitsOnValidEdit(false);
  82:     setOverwriteMode(false);
  83:   }
  84: 
  85:   /**
  86:    * Creates a new InternationalFormatter that uses the specified
  87:    * Format object for value to string conversion.
  88:    *
  89:    * @param format the Format object to use for value to string conversion
  90:    */
  91:   public InternationalFormatter(Format format)
  92:   {
  93:     this();
  94:     setFormat(format);
  95:   }
  96: 
  97:   /**
  98:    * Sets the Format object that is used to convert values to strings.
  99:    *
 100:    * @param format the Format to use for value to string conversion
 101:    *
 102:    * @see Format
 103:    */
 104:   public void setFormat(Format format)
 105:   {
 106:     this.format = format;
 107:   }
 108: 
 109:   /**
 110:    * Returns the currently used Format object that is used to format
 111:    * the JFormattedField.
 112:    *
 113:    * @return the current Format
 114:    */
 115:   public Format getFormat()
 116:   {
 117:     return format;
 118:   }
 119: 
 120:   /**
 121:    * Sets the minimum value that is allowed by this Formatter. The minimum
 122:    * value is given as an object that implements the {@link Comparable}
 123:    * interface.
 124:    *
 125:    * If <code>minValue</code> is null, then the Formatter has no restrictions
 126:    * at the lower end.
 127:    *
 128:    * If value class is not yet specified and <code>minValue</code> is not
 129:    * null, then <code>valueClass</code> is set to the class of the minimum
 130:    * value.
 131:    *
 132:    * @param minValue the minimum permissable value
 133:    *
 134:    * @see Comparable
 135:    */
 136:   public void setMinimum(Comparable minValue)
 137:   {
 138:     minimum = minValue;
 139:     if (valueClass == null && minValue != null)
 140:       valueClass = minValue.getClass();
 141:   }
 142: 
 143:   /**
 144:    * Returns the minimal value that is allowed by this Formatter.
 145:    *
 146:    * A <code>null</code> value means that there is no restriction.
 147:    *
 148:    * @return the minimal value that is allowed by this Formatter or
 149:    *     <code>null</code> if there is no restriction
 150:    */
 151:   public Comparable getMinimum()
 152:   {
 153:     return minimum;
 154:   }
 155: 
 156:   /**
 157:    * Sets the maximum value that is allowed by this Formatter. The maximum
 158:    * value is given as an object that implements the {@link Comparable}
 159:    * interface.
 160:    *
 161:    * If <code>maxValue</code> is null, then the Formatter has no restrictions
 162:    * at the upper end.
 163:    *
 164:    * If value class is not yet specified and <code>maxValue</code> is not
 165:    * null, then <code>valueClass</code> is set to the class of the maximum
 166:    * value.
 167:    *
 168:    * @param maxValue the maximum permissable value
 169:    *
 170:    * @see Comparable
 171:    */
 172:   public void setMaximum(Comparable maxValue)
 173:   {
 174:     maximum = maxValue;
 175:     if (valueClass == null && maxValue != null)
 176:       valueClass = maxValue.getClass();
 177:   }
 178: 
 179:   /**
 180:    * Returns the maximal value that is allowed by this Formatter.
 181:    *
 182:    * A <code>null</code> value means that there is no restriction.
 183:    *
 184:    * @return the maximal value that is allowed by this Formatter or
 185:    *     <code>null</code> if there is no restriction
 186:    */
 187:   public Comparable getMaximum()
 188:   {
 189:     return maximum;
 190:   }
 191: 
 192:   /**
 193:    * Installs the formatter on the specified {@link JFormattedTextField}.
 194:    *
 195:    * This method does the following things:
 196:    * <ul>
 197:    * <li>Display the value of #valueToString in the
 198:    *  <code>JFormattedTextField</code></li>
 199:    * <li>Install the Actions from #getActions on the <code>JTextField</code>
 200:    * </li>
 201:    * <li>Install the DocumentFilter returned by #getDocumentFilter</li>
 202:    * <li>Install the NavigationFilter returned by #getNavigationFilter</li>
 203:    * </ul>
 204:    *
 205:    * This method is typically not overridden by subclasses. Instead override
 206:    * one of the mentioned methods in order to customize behaviour.
 207:    *
 208:    * @param ftf the {@link JFormattedTextField} in which this formatter
 209:    *     is installed 
 210:    */
 211:   public void install(JFormattedTextField ftf)
 212:   {
 213:     super.install(ftf);
 214:   }
 215: 
 216:   /**
 217:    * Converts a value object into a String. This is done by invoking
 218:    * {@link Format#format(Object)} on the specified <code>Format</code> object.
 219:    * If no format is set, then {@link DefaultFormatter#valueToString(Object)}
 220:    * is called as a fallback.
 221:    *
 222:    * @param value the value to be converted
 223:    *
 224:    * @return the string representation of the value
 225:    *
 226:    * @throws ParseException if the value cannot be converted
 227:    */
 228:   public String valueToString(Object value)
 229:     throws ParseException
 230:   {
 231:     if (value == null)
 232:       return "";
 233:     if (format != null)
 234:       return format.format(value);
 235:     else
 236:       return super.valueToString(value);
 237:   }
 238: 
 239:   /**
 240:    * Converts a String (from the JFormattedTextField input) to a value.
 241:    * This is achieved by invoking {@link Format#parseObject(String)} on
 242:    * the specified <code>Format</code> object.
 243:    *
 244:    * This implementation differs slightly from {@link DefaultFormatter},
 245:    * it does:
 246:    * <ol>
 247:    * <li>Convert the string to an <code>Object</code> using the
 248:    *   <code>Formatter</code>.</li>
 249:    * <li>If a <code>valueClass</code> has been set, this object is passed to
 250:    *   {@link DefaultFormatter#stringToValue(String)} so that the value
 251:    *   has the correct type. This may or may not work correctly, depending on
 252:    *   the implementation of toString() in the value class and if the class
 253:    *   implements a constructor that takes one String as argument.</li>
 254:    * <li>If no {@link ParseException} has been thrown so far, we check if the
 255:    *   value exceeds either <code>minimum</code> or <code>maximum</code> if
 256:    *   one of those has been specified and throw a <code>ParseException</code>
 257:    *   if it does.</li>
 258:    * <li>Return the value.</li>
 259:    * </ol>
 260:    *
 261:    * If no format has been specified, then
 262:    * {@link DefaultFormatter#stringToValue(String)} is invoked as fallback.
 263:    *
 264:    * @param string the string to convert
 265:    *
 266:    * @return the value for the string
 267:    *
 268:    * @throws ParseException if the string cannot be converted into
 269:    *     a value object (e.g. invalid input)
 270:    */
 271:   public Object stringToValue(String string)
 272:     throws ParseException
 273:   {
 274:     if (format != null)
 275:       {
 276:         Object o = format.parseObject(string);
 277: 
 278:         // If a value class has been set, call super in order to get
 279:         // the class right. That is what the JDK API docs suggest, so we do
 280:         // it that way.
 281:         if (valueClass != null)
 282:           o = super.stringToValue(o.toString());
 283: 
 284:         // Check for minimum and maximum bounds
 285:         if (minimum != null && minimum.compareTo(o) > 0)
 286:           throw new ParseException("The value may not be less than the"
 287:                                     + " specified minimum", 0);
 288:         if (maximum != null && maximum.compareTo(o) < 0)
 289:           throw new ParseException("The value may not be greater than the"
 290:                                     + " specified maximum", 0);
 291:         return o;
 292:       }
 293:     else
 294:       return super.stringToValue(string);
 295:   }
 296: 
 297:   /**
 298:    * Returns the {@link Format.Field} constants that are associated with
 299:    * the specified position in the text.
 300:    *
 301:    * If <code>offset</code> is not a valid location in the input field,
 302:    * an empty array of fields is returned.
 303:    *
 304:    * @param offset the position in the text from which we want to fetch
 305:    *     the fields constants
 306:    *
 307:    * @return the field values associated with the specified position in
 308:    *     the text
 309:    */
 310:   public Format.Field[] getFields(int offset)
 311:   {
 312:     // TODO: don't know if this is correct
 313:     AttributedCharacterIterator aci = format.formatToCharacterIterator
 314:                                          (getFormattedTextField().getValue());
 315:     aci.setIndex(offset);
 316:     Map atts = aci.getAttributes();
 317:     Set keys = atts.keySet();
 318:     Format.Field[] fields = new Format.Field[keys.size()];
 319:     int index = 0;
 320:     for (Iterator i = keys.iterator(); i.hasNext(); index++)
 321:       fields[index] = (Format.Field) i.next();
 322:     return fields;
 323:   }
 324: 
 325:   /**
 326:    * This creates and returns a clone of this Formatter.
 327:    *
 328:    * @return a clone of this formatter
 329:    *
 330:    * @throws CloneNotSupportedException not thrown here, since cloning is
 331:    *     supported
 332:    */
 333:   public Object clone()
 334:     throws CloneNotSupportedException
 335:   {
 336:     // TODO: it has to be considered, if we should return a deep or shallow
 337:     // clone here. for now we return a shallow clone
 338:     Object clone = super.clone();
 339:     return clone;
 340:   }
 341: 
 342:   /**
 343:    * Returns the Actions that are supported by this Formatter.
 344:    *
 345:    * @specnote the JDK API docs say here: <cite>If
 346:    *     <code>getSupportsIncrement</code> returns true, this returns two
 347:    *     Actions suitable for incrementing/decrementing the value.</cite>
 348:    *     The questsion is, which method <code>getSupportsIncrement</code>?
 349:    *     There is no such method in the whole API! So we just call
 350:    *     super.getActions here.
 351:    */
 352:   protected Action[] getActions()
 353:   {
 354:     return super.getActions();
 355:   }
 356: }