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1   /*
2    * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package javax.accessibility;
27  
28  /**
29   * The AccessibleValue interface should be supported by any object
30   * that supports a numerical value (e.g., a scroll bar).  This interface
31   * provides the standard mechanism for an assistive technology to determine
32   * and set the numerical value as well as get the minimum and maximum values.
33   * Applications can determine
34   * if an object supports the AccessibleValue interface by first
35   * obtaining its AccessibleContext (see
36   * {@link Accessible}) and then calling the
37   * {@link AccessibleContext#getAccessibleValue} method.
38   * If the return value is not null, the object supports this interface.
39   *
40   * @see Accessible
41   * @see Accessible#getAccessibleContext
42   * @see AccessibleContext
43   * @see AccessibleContext#getAccessibleValue
44   *
45   * @author      Peter Korn
46   * @author      Hans Muller
47   * @author      Willie Walker
48   */
49  public interface AccessibleValue {
50  
51      /**
52       * Get the value of this object as a Number.  If the value has not been
53       * set, the return value will be null.
54       *
55       * @return value of the object
56       * @see #setCurrentAccessibleValue
57       */
58      public Number getCurrentAccessibleValue();
59  
60      /**
61       * Set the value of this object as a Number.
62       *
63       * @param n the number to use for the value
64       * @return True if the value was set; else False
65       * @see #getCurrentAccessibleValue
66       */
67      public boolean setCurrentAccessibleValue(Number n);
68  
69  //    /**
70  //     * Get the description of the value of this object.
71  //     *
72  //     * @return description of the value of the object
73  //     */
74  //    public String getAccessibleValueDescription();
75  
76      /**
77       * Get the minimum value of this object as a Number.
78       *
79       * @return Minimum value of the object; null if this object does not
80       * have a minimum value
81       * @see #getMaximumAccessibleValue
82       */
83      public Number getMinimumAccessibleValue();
84  
85      /**
86       * Get the maximum value of this object as a Number.
87       *
88       * @return Maximum value of the object; null if this object does not
89       * have a maximum value
90       * @see #getMinimumAccessibleValue
91       */
92      public Number getMaximumAccessibleValue();
93  }