libjava/javax/accessibility/AccessibleHyperlink.java

   1 /* AccessibleHyperlink.java -- aids in accessibly navigating hypertext
   2    Copyright (C) 2002, 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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.accessibility;
  40
  41 /**
  42  * This object encapsulates actions associated with navigating hypertext.
  43  *
  44  * @author Eric Blake (ebb9@email.byu.edu)
  45  * @see Accessible
  46  * @see AccessibleContext
  47  * @see AccessibleText
  48  * @see AccessibleContext#getAccessibleText()
  49  * @since 1.2
  50  * @status updated to 1.4
  51  */
  52 public abstract class AccessibleHyperlink implements AccessibleAction
  53 {
  54   /**
  55    * The default constructor.
  56    */
  57   public AccessibleHyperlink()
  58   {
  59   }
  60
  61   /**
  62    * Returns whether the document the link references is still valid, as the
  63    * association may have changed with a text edit.
  64    *
  65    * @return true if the link is valid with respect to the AccessibleHypertext
  66    */
  67   public abstract boolean isValid();
  68
  69   /**
  70    * Get the number possible actions for this object, starting from 0. In
  71    * general, a hypertext link has only one action, except for an image map,
  72    * so there isn't really a default action.
  73    *
  74    * @return the 0-based number of actions
  75    */
  76   public abstract int getAccessibleActionCount();
  77
  78   /**
  79    * Perform the specified action. Does nothing if out of bounds.
  80    *
  81    * @param i the action to perform, 0-based
  82    * @return true if the action was performed
  83    * @see #getAccessibleActionCount()
  84    */
  85   public abstract boolean doAccessibleAction(int i);
  86
  87   /**
  88    * Get the anchor text of the link, or null if the index is out of bounds.
  89    * For example, &lt;a href="http://www.gnu.org/"&gt;GNU Home Page&lt;/a&gt;
  90    * would return "GNU Home Page", while &lt;a HREF="#top"&gt;
  91    * &lt;img src="top-hat.png" alt="top hat"&gt;&lt;/a&gt; would return
  92    * "top hat".
  93    *
  94    * @param i the link to retrieve, 0-based
  95    * @return the link anchor text
  96    * @see #getAccessibleActionCount()
  97    */
  98   public abstract String getAccessibleActionDescription(int i);
  99
 100   /**
 101    * Get the link location, or null if the index is out of bounds. For
 102    * example, &lt;a href="http://www.gnu.org/"&gt;GNU Home Page&lt;/a&gt;
 103    * would return a java.net.URL("http://www.gnu.org/").
 104    *
 105    * @param i the link to retrieve, 0-based
 106    * @return the link location
 107    * @see #getAccessibleActionCount()
 108    */
 109   public abstract Object getAccessibleActionObject(int i);
 110
 111   /**
 112    * Get the anchor appropriate for the link, or null if the index is out of
 113    * bounds. For example, &lt;a href="http://www.gnu.org/"&gt;GNU Home Page
 114    * &lt;/a&gt; would return "GNU Home Page", while &lt;a HREF="#top"&gt;
 115    * &lt;img src="top-hat.png" alt="top hat"&gt;&lt;/a&gt; would return
 116    * an ImageIcon("top-hat.png", "top hat").
 117    *
 118    * @param i the link to retrieve, 0-based
 119    * @return the link anchor object
 120    * @see #getAccessibleActionCount()
 121    */
 122   public abstract Object getAccessibleActionAnchor(int i);
 123
 124   /**
 125    * Gets the character index where this link starts in the parent hypertext
 126    * document.
 127    *
 128    * @return the starting index
 129    */
 130   public abstract int getStartIndex();
 131
 132   /**
 133    * Gets the character index where this link ends in the parent hypertext
 134    * document.
 135    *
 136    * @return the ending index
 137    */
 138   public abstract int getEndIndex();
 139 } // class AccessibleAction