libjava/external/sax/org/xml/sax/helpers/AttributeListImpl.java

   1 // SAX default implementation for AttributeList.
   2 // http://www.saxproject.org
   3 // No warranty; no copyright -- use this as you will.
   4 // $Id: AttributeListImpl.java,v 1.1 2005/02/02 00:41:53 tromey Exp $
   5
   6 package org.xml.sax.helpers;
   7
   8 import org.xml.sax.AttributeList;
   9
  10 import java.util.Vector;
  11
  12
  13 /**
  14  * Default implementation for AttributeList.
  15  *
  16  * <blockquote>
  17  * <em>This module, both source code and documentation, is in the
  18  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  19  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  20  * for further information.
  21  * </blockquote>
  22  *
  23  * <p>AttributeList implements the deprecated SAX1 {@link
  24  * org.xml.sax.AttributeList AttributeList} interface, and has been
  25  * replaced by the new SAX2 {@link org.xml.sax.helpers.AttributesImpl
  26  * AttributesImpl} interface.</p>
  27  *
  28  * <p>This class provides a convenience implementation of the SAX
  29  * {@link org.xml.sax.AttributeList AttributeList} interface.  This
  30  * implementation is useful both for SAX parser writers, who can use
  31  * it to provide attributes to the application, and for SAX application
  32  * writers, who can use it to create a persistent copy of an element's
  33  * attribute specifications:</p>
  34  *
  35  * <pre>
  36  * private AttributeList myatts;
  37  *
  38  * public void startElement (String name, AttributeList atts)
  39  * {
  40  *              // create a persistent copy of the attribute list
  41  *              // for use outside this method
  42  *   myatts = new AttributeListImpl(atts);
  43  *   [...]
  44  * }
  45  * </pre>
  46  *
  47  * <p>Please note that SAX parsers are not required to use this
  48  * class to provide an implementation of AttributeList; it is
  49  * supplied only as an optional convenience.  In particular,
  50  * parser writers are encouraged to invent more efficient
  51  * implementations.</p>
  52  *
  53  * @deprecated This class implements a deprecated interface,
  54  *             {@link org.xml.sax.AttributeList AttributeList};
  55  *             that interface has been replaced by
  56  *             {@link org.xml.sax.Attributes Attributes},
  57  *             which is implemented in the
  58  *             {@link org.xml.sax.helpers.AttributesImpl
  59  *            AttributesImpl} helper class.
  60  * @since SAX 1.0
  61  * @author David Megginson
  62  * @version 2.0.1 (sax2r2)
  63  * @see org.xml.sax.AttributeList
  64  * @see org.xml.sax.DocumentHandler#startElement
  65  */
  66 public class AttributeListImpl implements AttributeList
  67 {
  68
  69     /**
  70      * Create an empty attribute list.
  71      *
  72      * <p>This constructor is most useful for parser writers, who
  73      * will use it to create a single, reusable attribute list that
  74      * can be reset with the clear method between elements.</p>
  75      *
  76      * @see #addAttribute
  77      * @see #clear
  78      */
  79     public AttributeListImpl ()
  80     {
  81     }
  82
  83
  84     /**
  85      * Construct a persistent copy of an existing attribute list.
  86      *
  87      * <p>This constructor is most useful for application writers,
  88      * who will use it to create a persistent copy of an existing
  89      * attribute list.</p>
  90      *
  91      * @param atts The attribute list to copy
  92      * @see org.xml.sax.DocumentHandler#startElement
  93      */
  94     public AttributeListImpl (AttributeList atts)
  95     {
  96         setAttributeList(atts);
  97     }
  98
  99
 100 \f
 101     ////////////////////////////////////////////////////////////////////
 102     // Methods specific to this class.
 103     ////////////////////////////////////////////////////////////////////
 104
 105
 106     /**
 107      * Set the attribute list, discarding previous contents.
 108      *
 109      * <p>This method allows an application writer to reuse an
 110      * attribute list easily.</p>
 111      *
 112      * @param atts The attribute list to copy.
 113      */
 114     public void setAttributeList (AttributeList atts)
 115     {
 116         int count = atts.getLength();
 117
 118         clear();
 119
 120         for (int i = 0; i < count; i++) {
 121             addAttribute(atts.getName(i), atts.getType(i), atts.getValue(i));
 122         }
 123     }
 124
 125
 126     /**
 127      * Add an attribute to an attribute list.
 128      *
 129      * <p>This method is provided for SAX parser writers, to allow them
 130      * to build up an attribute list incrementally before delivering
 131      * it to the application.</p>
 132      *
 133      * @param name The attribute name.
 134      * @param type The attribute type ("NMTOKEN" for an enumeration).
 135      * @param value The attribute value (must not be null).
 136      * @see #removeAttribute
 137      * @see org.xml.sax.DocumentHandler#startElement
 138      */
 139     public void addAttribute (String name, String type, String value)
 140     {
 141         names.addElement(name);
 142         types.addElement(type);
 143         values.addElement(value);
 144     }
 145
 146
 147     /**
 148      * Remove an attribute from the list.
 149      *
 150      * <p>SAX application writers can use this method to filter an
 151      * attribute out of an AttributeList.  Note that invoking this
 152      * method will change the length of the attribute list and
 153      * some of the attribute's indices.</p>
 154      *
 155      * <p>If the requested attribute is not in the list, this is
 156      * a no-op.</p>
 157      *
 158      * @param name The attribute name.
 159      * @see #addAttribute
 160      */
 161     public void removeAttribute (String name)
 162     {
 163         int i = names.indexOf(name);
 164
 165         if (i >= 0) {
 166             names.removeElementAt(i);
 167             types.removeElementAt(i);
 168             values.removeElementAt(i);
 169         }
 170     }
 171
 172
 173     /**
 174      * Clear the attribute list.
 175      *
 176      * <p>SAX parser writers can use this method to reset the attribute
 177      * list between DocumentHandler.startElement events.  Normally,
 178      * it will make sense to reuse the same AttributeListImpl object
 179      * rather than allocating a new one each time.</p>
 180      *
 181      * @see org.xml.sax.DocumentHandler#startElement
 182      */
 183     public void clear ()
 184     {
 185         names.removeAllElements();
 186         types.removeAllElements();
 187         values.removeAllElements();
 188     }
 189
 190
 191 \f
 192     ////////////////////////////////////////////////////////////////////
 193     // Implementation of org.xml.sax.AttributeList
 194     ////////////////////////////////////////////////////////////////////
 195
 196
 197     /**
 198      * Return the number of attributes in the list.
 199      *
 200      * @return The number of attributes in the list.
 201      * @see org.xml.sax.AttributeList#getLength
 202      */
 203     public int getLength ()
 204     {
 205         return names.size();
 206     }
 207
 208
 209     /**
 210      * Get the name of an attribute (by position).
 211      *
 212      * @param i The position of the attribute in the list.
 213      * @return The attribute name as a string, or null if there
 214      *         is no attribute at that position.
 215      * @see org.xml.sax.AttributeList#getName(int)
 216      */
 217     public String getName (int i)
 218     {
 219         if (i < 0) {
 220             return null;
 221         }
 222         try {
 223             return (String)names.elementAt(i);
 224         } catch (ArrayIndexOutOfBoundsException e) {
 225             return null;
 226         }
 227     }
 228
 229
 230     /**
 231      * Get the type of an attribute (by position).
 232      *
 233      * @param i The position of the attribute in the list.
 234      * @return The attribute type as a string ("NMTOKEN" for an
 235      *         enumeration, and "CDATA" if no declaration was
 236      *         read), or null if there is no attribute at
 237      *         that position.
 238      * @see org.xml.sax.AttributeList#getType(int)
 239      */
 240     public String getType (int i)
 241     {
 242         if (i < 0) {
 243             return null;
 244         }
 245         try {
 246             return (String)types.elementAt(i);
 247         } catch (ArrayIndexOutOfBoundsException e) {
 248             return null;
 249         }
 250     }
 251
 252
 253     /**
 254      * Get the value of an attribute (by position).
 255      *
 256      * @param i The position of the attribute in the list.
 257      * @return The attribute value as a string, or null if
 258      *         there is no attribute at that position.
 259      * @see org.xml.sax.AttributeList#getValue(int)
 260      */
 261     public String getValue (int i)
 262     {
 263         if (i < 0) {
 264             return null;
 265         }
 266         try {
 267             return (String)values.elementAt(i);
 268         } catch (ArrayIndexOutOfBoundsException e) {
 269             return null;
 270         }
 271     }
 272
 273
 274     /**
 275      * Get the type of an attribute (by name).
 276      *
 277      * @param name The attribute name.
 278      * @return The attribute type as a string ("NMTOKEN" for an
 279      *         enumeration, and "CDATA" if no declaration was
 280      *         read).
 281      * @see org.xml.sax.AttributeList#getType(java.lang.String)
 282      */
 283     public String getType (String name)
 284     {
 285         return getType(names.indexOf(name));
 286     }
 287
 288
 289     /**
 290      * Get the value of an attribute (by name).
 291      *
 292      * @param name The attribute name.
 293      * @see org.xml.sax.AttributeList#getValue(java.lang.String)
 294      */
 295     public String getValue (String name)
 296     {
 297         return getValue(names.indexOf(name));
 298     }
 299
 300
 301 \f
 302     ////////////////////////////////////////////////////////////////////
 303     // Internal state.
 304     ////////////////////////////////////////////////////////////////////
 305
 306     Vector names = new Vector();
 307     Vector types = new Vector();
 308     Vector values = new Vector();
 309
 310 }
 311
 312 // end of AttributeListImpl.java