libjava/classpath/javax/accessibility/AccessibleStateSet.java

   1 /* AccessibleStateSet.java -- the combined state of an accessible object
   2    Copyright (C) 2002, 2005 Free Software Foundation
   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 package javax.accessibility;
  39
  40 import gnu.java.lang.CPStringBuilder;
  41
  42 import java.util.Locale;
  43 import java.util.Vector;
  44
  45 /**
  46  * Describes all elements of an accessible object's state. For example, an
  47  * object may be enabled and have focus.
  48  *
  49  * @author Eric Blake (ebb9@email.byu.edu)
  50  * @see AccessibleState
  51  * @since 1.2
  52  * @status updated to 1.4
  53  */
  54 public class AccessibleStateSet
  55 {
  56   /**
  57    * The list of states, should be instances of AccessibleState. Don't set
  58    * this to null.
  59    *
  60    * @see #add(AccessibleState)
  61    * @see #addAll(AccessibleState[])
  62    * @see #remove(AccessibleState)
  63    * @see #contains(AccessibleState)
  64    * @see #toArray()
  65    * @see #clear()
  66    */
  67   protected Vector<AccessibleState> states = new Vector<AccessibleState>();
  68
  69   /**
  70    * Create an empty state set.
  71    */
  72   public AccessibleStateSet()
  73   {
  74   }
  75
  76   /**
  77    * Create a state set initialized with the given states, duplicates are
  78    * ignored.
  79    *
  80    * @param states the states to insert
  81    * @throws NullPointerException if states is null
  82    */
  83   public AccessibleStateSet(AccessibleState[] states)
  84   {
  85     addAll(states);
  86   }
  87
  88   /**
  89    * Add a new state to the current set. Return true if the state was added,
  90    * as duplicates are ignored. Entering a null state will cause problems
  91    * later, so don't do it.
  92    *
  93    * @param state the state to add
  94    * @return true if the state was added
  95    */
  96   public boolean add(AccessibleState state)
  97   {
  98     return states.contains(state) ? false : states.add(state);
  99   }
 100
 101   /**
 102    * Add all of the states to the current set. Duplicates are ignored.
 103    * Entering a null state will cause problems later, so don't do it.
 104    *
 105    * @param array the array of states to add
 106    * @throws NullPointerException if array is null
 107    */
 108   public void addAll(AccessibleState[] array)
 109   {
 110     int i = array.length;
 111     while (--i >= 0)
 112       add(array[i]);
 113   }
 114
 115   /**
 116    * Remove a state from the set. If a state was removed, return true.
 117    *
 118    * @param state the state to remove
 119    * @return true if the set changed
 120    */
 121   public boolean remove(AccessibleState state)
 122   {
 123     return states.remove(state);
 124   }
 125
 126   /**
 127    * Clear all states in the set.
 128    */
 129   public void clear()
 130   {
 131     states.clear();
 132   }
 133
 134   /**
 135    * Check if the current state is in the set.
 136    *
 137    * @param state the state to locate
 138    * @return true if it is in the set
 139    */
 140   public boolean contains(AccessibleState state)
 141   {
 142     return states.contains(state);
 143   }
 144
 145   /**
 146    * Return the state set as an array.
 147    *
 148    * @return an array of the current states
 149    */
 150   public AccessibleState[] toArray()
 151   {
 152     AccessibleState[] result = new AccessibleState[states.size()];
 153     states.toArray(result);
 154     return result;
 155   }
 156
 157   /**
 158    * Return a localized, comma-separated string representing all states
 159    * in the set. This is in arbitrary order.
 160    *
 161    * @return the string representation
 162    * @see AccessibleBundle#toDisplayString(String, Locale)
 163    */
 164   public String toString()
 165   {
 166     int i = states.size();
 167     if (i == 0)
 168       return "";
 169     // Pre-allocate an average of 10 chars per state.
 170     CPStringBuilder b = new CPStringBuilder(i * 10);
 171     while (--i >= 0)
 172       b.append(states.get(i)).append(',');
 173     return b.substring(0, b.length() - 1);
 174   }
 175 } // class AccessibleStateSet