001/* AccessibleAction.java -- aids in accessibly performing actions
002   Copyright (C) 2000, 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 * If an object implements this interface then it must be able to perform one
043 * or more actions. Accessibility software can use the implementations of this
044 * interface to discover and perform actions on an object.
045 *
046 * <p>The <code>AccessibleContext.getAccessibleAction()</code> method should
047 * return <code>null</code> if an object does not implement this interface.
048 *
049 * @author Eric Blake (ebb9@email.byu.edu)
050 * @see Accessible
051 * @see AccessibleContext
052 * @see AccessibleContext#getAccessibleAction()
053 * @since 1.2
054 * @status updated to 1.4
055 */
056public interface AccessibleAction
057{
058
059  /**
060   * The name of an action which decrements a value.
061   *
062   * @since 1.5
063   */
064  static final String DECREMENT = "decrement";
065
066  /**
067   * The name of an action which increments a value.
068   *
069   * @since 1.5
070   */
071  static final String INCREMENT = "increment";
072
073  /**
074   * The name of an action which toggles the expansion of a tree node.
075   *
076   * @since 1.5
077   */
078  static final String TOGGLE_EXPAND = "toggle expand";
079
080  /**
081   * The name of an action which causes a component to perform its default
082   * action.
083   *
084   * @since 1.6
085   */
086  static final String CLICK = "click";
087
088  /**
089   * The name of an action which toggles the state of a popup, causing a
090   * hidden popup to be displayed and a visible popup to be hidden.
091   *
092   * @since 1.6
093   */
094  static final String TOGGLE_POPUP = "toggle popup";
095
096  /**
097   * Get the number possible actions for this object, with the zeroth
098   * representing the default action.
099   *
100   * @return the 0-based number of actions
101   */
102  int getAccessibleActionCount();
103
104  /**
105   * Get a description for the specified action. Returns null if out of
106   * bounds.
107   *
108   * @param i the action to describe, 0-based
109   * @return description of the action
110   */
111  String getAccessibleActionDescription(int i);
112
113  /**
114   * Perform the specified action. Does nothing if out of bounds.
115   *
116   * @param i the action to perform, 0-based
117   * @return true if the action was performed
118   */
119  boolean doAccessibleAction(int i);
120} // interface AccessibleAction