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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2003 Samuel Goldstein
6    *
7    * Part of Melati (http://melati.org), a framework for the rapid
8    * development of clean, maintainable web applications.
9    *
10   * Melati is free software; Permission is granted to copy, distribute
11   * and/or modify this software under the terms either:
12   *
13   * a) the GNU General Public License as published by the Free Software
14   *    Foundation; either version 2 of the License, or (at your option)
15   *    any later version,
16   *
17   *    or
18   *
19   * b) any version of the Melati Software License, as published
20   *    at http://melati.org
21   *
22   * You should have received a copy of the GNU General Public License and
23   * the Melati Software License along with this program;
24   * if not, write to the Free Software Foundation, Inc.,
25   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26   * GNU General Public License and visit http://melati.org to obtain the
27   * Melati Software License.
28   *
29   * Feel free to contact the Developers of Melati (http://melati.org),
30   * if you would like to work out a different arrangement than the options
31   * outlined here.  It is our intention to allow Melati to be used by as
32   * wide an audience as possible.
33   *
34   * This program is distributed in the hope that it will be useful,
35   * but WITHOUT ANY WARRANTY; without even the implied warranty of
36   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
37   * GNU General Public License for more details.
38   *
39   * Contact details for copyright holder:
40   *
41   *     Samuel Goldstein <samuel@1969.ws>
42   *     http://www.1969.ws
43   *     13101 W. Washington Blvd Suite 248, Los Angeles, CA 90066 USA
44   */
45  
46  package org.melati.poem.prepro;
47  
48  import java.io.StreamTokenizer;
49  import java.io.IOException;
50  
51  /**
52   * A <tt>FieldQualifier</TT> which enables the precision of 
53   * BigDecimals to be specified.
54   */
55  public class PrecisionFieldQualifier extends FieldQualifier {
56  
57    private int precision;
58  
59   /**
60    * Constructor.
61    *
62    * @param tokens the <code>StreamTokenizer</code> to get tokens from
63    *
64    * @throws ParsingDSDException if an unexpected token is encountered
65    * @throws IOException if something goes wrong with the file system
66    */
67    public PrecisionFieldQualifier(StreamTokenizer tokens)
68      throws ParsingDSDException, IOException {
69      DSD.expect(tokens, '=');
70      tokens.nextToken();
71      if (tokens.ttype != StreamTokenizer.TT_NUMBER || (int) tokens.nval <= 0)
72        throw new ParsingDSDException("<positive precision number>", tokens);
73      precision = (int) tokens.nval;
74      tokens.nextToken();
75    }
76  
77   /**
78    * Update the model.
79    *
80    * @param field the {@link FieldDef} to update
81    *
82    * @throws SizeApplicationException 
83    *           if this is a non-sizable field
84    */
85    public void apply(FieldDef field) throws SizeApplicationException {
86      if (field instanceof BigDecimalFieldDef)
87         ((BigDecimalFieldDef) field).setPrecision(precision);
88      else
89        throw new SizeApplicationException(field);
90    }
91  }