old-autovect-branch/libjava/classpath/javax/swing/text/html/parser/Element.java

   1 /* Element.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
  39 package javax.swing.text.html.parser;
  40
  41 import gnu.javax.swing.text.html.parser.support.gnuStringIntMapper;
  42
  43 import java.io.Serializable;
  44
  45 import java.util.BitSet;
  46
  47 /**
  48  * <p>
  49  * Stores the element information, obtained by parsing SGML DTD
  50  * tag <code>&lt;!ELEMENT .. &gt;</code>. This class has no public
  51  * constructor and can only be instantiated using the
  52  * {@link javax.swing.text.html.parser.DTD } methods</p>
  53  *
  54  * <p>SGML defines elements that represent structures or
  55  * behavior. An element typically consists of a start tag, content, and an
  56  * end tag. Hence the elements are not tags. The HTML 4.0 definition specifies
  57  * that some elements are not required to have the end tags. Also, some
  58  * HTML elements (like <code>&lt;hr&gt;</code>) have no content. Element names
  59  * are case sensitive.</p>
  60  * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
  61  */
  62 public final class Element
  63   implements DTDConstants, Serializable
  64 {
  65   /**
  66    * Package level mapper between type names and they string values.
  67    */
  68   static final gnuStringIntMapper mapper =
  69     new gnuStringIntMapper()
  70     {
  71       protected void create()
  72       {
  73         add("CDATA", DTDConstants.CDATA);
  74         add("RCDATA", DTDConstants.RCDATA);
  75         add("EMPTY", DTDConstants.EMPTY);
  76         add("ANY", DTDConstants.ANY);
  77       }
  78     };
  79
  80   /** Use serialVersionUID for interoperability. */
  81   private static final long serialVersionUID = -6717939384601675586L;
  82
  83   /**
  84    * The element attributes.
  85    */
  86   public AttributeList atts;
  87
  88   /**
  89    * Contains refernces to elements that must NOT occur inside this element,
  90    * at any level of hierarchy.
  91    */
  92   public BitSet exclusions;
  93
  94   /**
  95    * Contains refernces to elements that must CAN occur inside this element,
  96    * at any level of hierarchy.
  97    */
  98   public BitSet inclusions;
  99
 100   /**
 101    * The content model, defining elements, entities and DTD text
 102    * that may/may not occur inside this element.
 103    */
 104   public ContentModel content;
 105
 106   /**
 107    * A field to store additional user data for this Element.
 108    */
 109   public Object data;
 110
 111   /**
 112    * The element name.
 113    */
 114   public String name;
 115
 116   /**
 117    * True is this element need not to have the closing tag, false
 118    * otherwise. The HTML 4.0 definition specifies
 119    * that some elements (like <code>&lt;hr&gt;</code>are
 120    * not required to have the end tags.
 121    */
 122   public boolean oEnd;
 123
 124   /**
 125    * True is this element need not to have the starting tag, false
 126    * otherwise. The HTML 4.0 definition specifies
 127    * that some elements (like <code>&lt;head&gt;</code> or
 128    * <code>&lt;body&gt;</code>) are
 129    * not required to have the start tags.
 130
 131    */
 132   public boolean oStart;
 133
 134   /**
 135    * This field contains the unique integer identifier of this Element,
 136    * used to refer the element (more exactly, the element flag)
 137    * in <code>inclusions</code> and <code>exclusions</code> bit set.
 138    */
 139   public int index;
 140
 141   /**
 142    * The element type, containing value, defined in DTDConstants.
 143    * In this implementation, the element type can be
 144    * CDATA, RCDATA, EMPTY or ANY.
 145    */
 146   public int type;
 147
 148   /**
 149    * The default constructor must have package level access in this
 150    * class. Use DTD.defineElement(..) to create an element when required.
 151    */
 152   Element()
 153   {
 154     // Nothing to do here.
 155   }
 156
 157   /**
 158    * Converts the string representation of the element type
 159    * into its unique integer identifier, defined in DTDConstants.
 160    * @param a_type A name of the type
 161    * @return DTDConstants.CDATA, DTDConstants.RCDATA, DTDConstants.EMPTY,
 162    * DTDConstants.ANY or null if the type name is not
 163    * "CDATA", "RCDATA", "EMPTY" or "ANY". This function is case sensitive.
 164    * @throws NullPointerException if <code>a_type</code> is null.
 165    */
 166   public static int name2type(String a_type)
 167   {
 168     return mapper.get(a_type);
 169   }
 170
 171   /**
 172    * Get the element attribute by name.
 173    * @param attribute the attribute name, case insensitive.
 174    * @return the correspoding attribute of this element. The class,
 175    * for storing as attribute list, as a single attribute, is used to
 176    * store a single attribute in this case.
 177    * @throws NullPointerException if the attribute name is null.
 178    */
 179   public AttributeList getAttribute(String attribute)
 180   {
 181     AttributeList a = atts;
 182
 183     while (a != null && !attribute.equalsIgnoreCase(a.name))
 184       a = a.next;
 185
 186     return a;
 187   }
 188
 189   /**
 190    * Get the element attribute by its value.
 191    * @param a_value the attribute value, case insensitive.
 192    * @return the correspoding attribute of this element. The class,
 193    * for storing as attribute list, as a single attribute, is used to
 194    * store a single attribute in this case. If there are several
 195    * attributes with the same value, there is no garranty, which one
 196    * is returned.
 197    */
 198   public AttributeList getAttributeByValue(String a_value)
 199   {
 200     AttributeList a = atts;
 201
 202     if (a_value == null)
 203       {
 204         while (a != null)
 205           {
 206             if (a.value == null)
 207               return a;
 208
 209             a = a.next;
 210           }
 211       }
 212     else
 213       {
 214         while (a != null)
 215           {
 216             if (a.value != null && a_value.equalsIgnoreCase(a.value))
 217               return a;
 218
 219             a = a.next;
 220           }
 221       }
 222
 223     return null;
 224   }
 225
 226   /**
 227    * Get all attributes of this document as an attribute list.
 228    * @return The attribute list.
 229    */
 230   public AttributeList getAttributes()
 231   {
 232     return atts;
 233   }
 234
 235   /**
 236    * Get the content model, defining elements, entities and DTD text
 237    * that may/may not occur inside this element.
 238    */
 239   public ContentModel getContent()
 240   {
 241     return content;
 242   }
 243
 244   /**
 245    * Returns true for the element with no content.
 246    * Empty elements are defined with the SGML DTD keyword "EMPTY".
 247    * @return true if content model field (content) method is equal to
 248    * null or its method empty() returns true.
 249    */
 250   public boolean isEmpty()
 251   {
 252     return content == null || content.empty();
 253   }
 254
 255   /**
 256    * Get the unique integer identifier of this Element,
 257    * used to refer the element (more exactly, the element flag)
 258    * in <code>inclusions</code> and <code>exclusions</code> bit set.
 259    * WARNING: This value may not be the same between different
 260    * implementations.
 261    */
 262   public int getIndex()
 263   {
 264     return index;
 265   }
 266
 267   /**
 268    * Get the element name.
 269    */
 270   public String getName()
 271   {
 272     return name;
 273   }
 274
 275   /**
 276    * Get the element type.
 277    * @return one of the values, defined DTDConstants.
 278    * In this implementation, the element type can be
 279    * CDATA, RCDATA, EMPTY or ANY.
 280    */
 281   public int getType()
 282   {
 283     return type;
 284   }
 285
 286   /**
 287    * True is this element need not to have the starting tag, false
 288    * otherwise.s element need not to have the closing tag, false
 289    * otherwise. The HTML 4.0 definition specifies
 290    * that some elements (like <code>&lt;hr&gt;</code>are
 291    * not required to have the end tags.
 292    */
 293   public boolean omitEnd()
 294   {
 295     return oEnd;
 296   }
 297
 298   /**
 299    * True is this element need not to have the closing tag, false
 300    * otherwise. The HTML 4.0 definition specifies
 301    * that some elements (like <code>&lt;head&gt;</code> or
 302    * <code>&lt;body&gt;</code>) are
 303    * not required to have the start tags.
 304    */
 305   public boolean omitStart()
 306   {
 307     return oStart;
 308   }
 309
 310   /**
 311    * Returns the name of this element.
 312    */
 313   public String toString()
 314   {
 315     return name;
 316   }
 317 }