001/* ParserDelegator.java -- Delegator for ParserDocument.
002    Copyright (C) 2005 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038package javax.swing.text.html.parser;
039
040import gnu.javax.swing.text.html.parser.HTML_401F;
041
042import java.io.IOException;
043import java.io.Reader;
044import java.io.Serializable;
045
046import javax.swing.text.BadLocationException;
047import javax.swing.text.SimpleAttributeSet;
048import javax.swing.text.html.HTMLEditorKit;
049import javax.swing.text.html.HTMLEditorKit.ParserCallback;
050
051/**
052 * This class instantiates and starts the working instance of
053 * html parser, being responsible for providing the default DTD.
054 *
055 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
056 */
057public class ParserDelegator
058  extends javax.swing.text.html.HTMLEditorKit.Parser
059  implements Serializable
060{
061  private class gnuParser
062    extends gnu.javax.swing.text.html.parser.support.Parser
063  {
064    private static final long serialVersionUID = 1;
065
066    private gnuParser(DTD d)
067    {
068      super(d);
069    }
070
071    protected final void handleComment(char[] comment)
072    {
073      callBack.handleComment(comment, hTag.where.startPosition);
074    }
075
076    protected final void handleEmptyTag(TagElement tag)
077      throws javax.swing.text.ChangedCharSetException
078    {
079      callBack.handleSimpleTag(tag.getHTMLTag(), getAttributes(),
080                               hTag.where.startPosition
081                              );
082    }
083
084    protected final void handleEndTag(TagElement tag)
085    {
086      callBack.handleEndTag(tag.getHTMLTag(), hTag.where.startPosition);
087    }
088
089    protected final void handleError(int line, String message)
090    {
091      callBack.handleError(message, hTag.where.startPosition);
092    }
093
094    protected final void handleStartTag(TagElement tag)
095    {
096      SimpleAttributeSet attributes = gnu.getAttributes();
097
098      if (tag.fictional())
099        attributes.addAttribute(ParserCallback.IMPLIED, Boolean.TRUE);
100
101      callBack.handleStartTag(tag.getHTMLTag(), attributes,
102                              hTag.where.startPosition
103                             );
104    }
105
106    protected final void handleText(char[] text)
107    {
108      callBack.handleText(text, hTag.where.startPosition);
109    }
110
111    DTD getDTD()
112    {
113      // Accessing the inherited gnu.javax.swing.text.html.parser.support.Parser
114      // field. super. is a workaround, required to support JDK1.3's javac.
115      return super.dtd;
116    }
117  }
118
119  /**
120   * Use serialVersionUID for interoperability.
121   */
122  private static final long serialVersionUID = -1276686502624777206L;
123
124  private static DTD dtd = HTML_401F.getInstance();
125
126  /**
127   * The callback.
128   * This is package-private to avoid an accessor method.
129   */
130  HTMLEditorKit.ParserCallback callBack;
131
132  /**
133   * The reference to the working class of HTML parser that is
134   * actually used to parse the document.
135   * This is package-private to avoid an accessor method.
136   */
137  gnuParser gnu;
138
139  /**
140   * Parses the HTML document, calling methods of the provided
141   * callback. This method must be multithread - safe.
142   * @param reader The reader to read the HTML document from
143   * @param a_callback The callback that is notifyed about the presence
144   * of HTML elements in the document.
145   * @param ignoreCharSet If thrue, any charset changes during parsing
146   * are ignored.
147   * @throws java.io.IOException
148   */
149  public void parse(Reader reader, HTMLEditorKit.ParserCallback a_callback,
150                    boolean ignoreCharSet
151                   )
152             throws IOException
153  {
154    callBack = a_callback;
155
156    if (gnu == null || !dtd.equals(gnu.getDTD()))
157      {
158        gnu = new gnuParser(dtd);
159      }
160
161    gnu.parse(reader);
162
163    callBack.handleEndOfLineString(gnu.getEndOfLineSequence());
164    try
165      {
166        callBack.flush();
167      }
168    catch (BadLocationException ex)
169      {
170        // Convert this into the supported type of exception.
171        throw new IOException(ex.getMessage());
172      }
173  }
174
175  /**
176   * Calling this method instructs that, if not specified directly,
177   * the documents will be parsed using the default
178   * DTD of the implementation.
179   */
180  protected static void setDefaultDTD()
181  {
182    dtd = HTML_401F.getInstance();
183  }
184
185  /**
186   * Registers the user - written DTD under the given name, also
187   * making it default for the subsequent parsings. This has effect on
188   * all subsequent calls to the parse(...) . If you need to specify
189   * your DTD locally, simply {@link javax.swing.text.html.parser.Parser}
190   * instead.
191   * @param a_dtd The DTD that will be used to parse documents by this class.
192   * @param name The name of this DTD.
193   * @return No standard is specified on which instance of DTD must be
194   * returned by this method, and it is recommended to leave the returned
195   * value without consideration. This implementation returns the DTD
196   * that was previously set as the default DTD, or the implementations
197   * default DTD if none was set.
198   */
199  protected static DTD createDTD(DTD a_dtd, String name)
200  {
201    DTD.putDTDHash(name, a_dtd);
202
203    DTD dtd_prev = dtd;
204    dtd = a_dtd;
205    return dtd_prev;
206  }
207}