Source for javax.accessibility.AccessibleValue

   1: /* AccessibleValue.java -- aids in accessibly controlling values
   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., 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.accessibility;
  40: 
  41: /**
  42:  * If an object implements this interface then it must be able to control
  43:  * a numerical value. For example, a scroll bar has a position represented
  44:  * by a number. Accessibility software can use the implementations of this
  45:  * interface to change the associated value.
  46:  *
  47:  * <p>The <code>AccessibleContext.getAccessibleValue()</code> method should
  48:  * return <code>null</code> if an object does not implement this interface.
  49:  *
  50:  * @author Eric Blake (ebb9@email.byu.edu)
  51:  * @see Accessible
  52:  * @see AccessibleContext
  53:  * @see AccessibleContext#getAccessibleValue()
  54:  * @since 1.2
  55:  * @status updated to 1.4
  56:  */
  57: public interface AccessibleValue
  58: {
  59:   /**
  60:    * Gets the current value of this object, or null if it has not been set.
  61:    *
  62:    * @return the current value, or null
  63:    * @see #setCurrentAccessibleValue(Number)
  64:    */
  65:   Number getCurrentAccessibleValue();
  66: 
  67:   /**
  68:    * Sets the current value of this object. Returns true if the number
  69:    * successfully changed.
  70:    *
  71:    * @param number the new value
  72:    * @return true on success
  73:    */
  74:   // XXX What happens if number is null?
  75:   boolean setCurrentAccessibleValue(Number number);
  76: 
  77:   /**
  78:    * Gets the minimum value in the range of this object, or null if there is
  79:    * no minimum.
  80:    *
  81:    * @return the minimum
  82:    * @see #getMaximumAccessibleValue()
  83:    */
  84:   Number getMinimumAccessibleValue();
  85: 
  86:   /**
  87:    * Gets the maximum value in the range of this object, or null if there is
  88:    * no maximum.
  89:    *
  90:    * @return the maximum
  91:    * @see #getMinimumAccessibleValue()
  92:    */
  93:   Number getMaximumAccessibleValue();
  94: } // interface AccessibleValue