001/* AccessibleHyperlink.java -- aids in accessibly navigating hypertext 002 Copyright (C) 2002, 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. */ 037 038 039package javax.accessibility; 040 041/** 042 * This object encapsulates actions associated with navigating hypertext. 043 * 044 * @author Eric Blake (ebb9@email.byu.edu) 045 * @see Accessible 046 * @see AccessibleContext 047 * @see AccessibleText 048 * @see AccessibleContext#getAccessibleText() 049 * @since 1.2 050 * @status updated to 1.4 051 */ 052public abstract class AccessibleHyperlink implements AccessibleAction 053{ 054 /** 055 * The default constructor. 056 */ 057 public AccessibleHyperlink() 058 { 059 } 060 061 /** 062 * Returns whether the document the link references is still valid, as the 063 * association may have changed with a text edit. 064 * 065 * @return true if the link is valid with respect to the AccessibleHypertext 066 */ 067 public abstract boolean isValid(); 068 069 /** 070 * Get the number possible actions for this object, starting from 0. In 071 * general, a hypertext link has only one action, except for an image map, 072 * so there isn't really a default action. 073 * 074 * @return the 0-based number of actions 075 */ 076 public abstract int getAccessibleActionCount(); 077 078 /** 079 * Perform the specified action. Does nothing if out of bounds. 080 * 081 * @param i the action to perform, 0-based 082 * @return true if the action was performed 083 * @see #getAccessibleActionCount() 084 */ 085 public abstract boolean doAccessibleAction(int i); 086 087 /** 088 * Get the anchor text of the link, or null if the index is out of bounds. 089 * For example, <a href="http://www.gnu.org/">GNU Home Page</a> 090 * would return "GNU Home Page", while <a HREF="#top"> 091 * <img src="top-hat.png" alt="top hat"></a> would return 092 * "top hat". 093 * 094 * @param i the link to retrieve, 0-based 095 * @return the link anchor text 096 * @see #getAccessibleActionCount() 097 */ 098 public abstract String getAccessibleActionDescription(int i); 099 100 /** 101 * Get the link location, or null if the index is out of bounds. For 102 * example, <a href="http://www.gnu.org/">GNU Home Page</a> 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, <a href="http://www.gnu.org/">GNU Home Page 114 * </a> would return "GNU Home Page", while <a HREF="#top"> 115 * <img src="top-hat.png" alt="top hat"></a> 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