Source for javax.swing.text.html.parser.ParserDelegator

   1: /* ParserDelegator.java -- Delegator for ParserDocument.
   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.html.parser;
  39: 
  40: import gnu.javax.swing.text.html.parser.HTML_401F;
  41: 
  42: import java.io.IOException;
  43: import java.io.Reader;
  44: import java.io.Serializable;
  45: 
  46: import javax.swing.text.BadLocationException;
  47: import javax.swing.text.SimpleAttributeSet;
  48: import javax.swing.text.html.HTMLEditorKit;
  49: import javax.swing.text.html.HTMLEditorKit.ParserCallback;
  50: 
  51: /**
  52:  * This class instantiates and starts the working instance of
  53:  * html parser, being responsible for providing the default DTD.
  54:  *
  55:  * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
  56:  */
  57: public class ParserDelegator
  58:   extends javax.swing.text.html.HTMLEditorKit.Parser
  59:   implements Serializable
  60: {
  61:   private class gnuParser
  62:     extends gnu.javax.swing.text.html.parser.support.Parser
  63:   {
  64:     private static final long serialVersionUID = 1;
  65: 
  66:     private gnuParser(DTD d)
  67:     {
  68:       super(d);
  69:     }
  70: 
  71:     protected final void handleComment(char[] comment)
  72:     {
  73:       callBack.handleComment(comment, hTag.where.startPosition);
  74:     }
  75: 
  76:     protected final void handleEmptyTag(TagElement tag)
  77:       throws javax.swing.text.ChangedCharSetException
  78:     {
  79:       callBack.handleSimpleTag(tag.getHTMLTag(), getAttributes(),
  80:                                hTag.where.startPosition
  81:                               );
  82:     }
  83: 
  84:     protected final void handleEndTag(TagElement tag)
  85:     {
  86:       callBack.handleEndTag(tag.getHTMLTag(), hTag.where.startPosition);
  87:     }
  88: 
  89:     protected final void handleError(int line, String message)
  90:     {
  91:       callBack.handleError(message, hTag.where.startPosition);
  92:     }
  93: 
  94:     protected final void handleStartTag(TagElement tag)
  95:     {
  96:       SimpleAttributeSet attributes = gnu.getAttributes();
  97: 
  98:       if (tag.fictional())
  99:         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: }