libjava/javax/accessibility/AccessibleStateSet.java

   1 /* AccessibleStateSet.java -- the combined state of an accessible object
   2    Copyright (C) 2002 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 java.util.Vector;
  41
  42 /**
  43  * Describes all elements of an accessible object's state. For example, an
  44  * object may be enabled and have focus.
  45  *
  46  * @author Eric Blake (ebb9@email.byu.edu)
  47  * @see AccessibleState
  48  * @since 1.2
  49  * @status updated to 1.4
  50  */
  51 public class AccessibleStateSet
  52 {
  53   /**
  54    * The list of states, should be instances of AccessibleState. Don't set
  55    * this to null.
  56    *
  57    * @see #add(AccessibleState)
  58    * @see #addAll(AccessibleState[])
  59    * @see #remove(AccessibleState)
  60    * @see #contains(AccessibleState)
  61    * @see #toArray()
  62    * @see #clear()
  63    */
  64   protected Vector states = new Vector();
  65
  66   /**
  67    * Create an empty state set.
  68    */
  69   public AccessibleStateSet()
  70   {
  71   }
  72
  73   /**
  74    * Create a state set initialized with the given states, duplicates are
  75    * ignored.
  76    *
  77    * @param states the states to insert
  78    * @throws NullPointerException if states is null
  79    */
  80   public AccessibleStateSet(AccessibleState[] states)
  81   {
  82     addAll(states);
  83   }
  84
  85   /**
  86    * Add a new state to the current set. Return true if the state was added,
  87    * as duplicates are ignored. Entering a null state will cause problems
  88    * later, so don't do it.
  89    *
  90    * @param state the state to add
  91    * @return true if the state was added
  92    */
  93   public boolean add(AccessibleState state)
  94   {
  95     return states.contains(state) ? false : states.add(state);
  96   }
  97
  98   /**
  99    * Add all of the states to the current set. Duplicates are ignored.
 100    * Entering a null state will cause problems later, so don't do it.
 101    *
 102    * @param array the array of states to add
 103    * @throws NullPointerException if array is null
 104    */
 105   public void addAll(AccessibleState[] array)
 106   {
 107     int i = array.length;
 108     while (--i >= 0)
 109       add(array[i]);
 110   }
 111
 112   /**
 113    * Remove a state from the set. If a state was removed, return true.
 114    *
 115    * @param state the state to remove
 116    * @return true if the set changed
 117    */
 118   public boolean remove(AccessibleState state)
 119   {
 120     return states.remove(state);
 121   }
 122
 123   /**
 124    * Clear all states in the set.
 125    */
 126   public void clear()
 127   {
 128     states.clear();
 129   }
 130
 131   /**
 132    * Check if the current state is in the set.
 133    *
 134    * @param state the state to locate
 135    * @return true if it is in the set
 136    */
 137   public boolean contains(AccessibleState state)
 138   {
 139     return states.contains(state);
 140   }
 141
 142   /**
 143    * Return the state set as an array.
 144    *
 145    * @return an array of the current states
 146    */
 147   public AccessibleState[] toArray()
 148   {
 149     AccessibleState[] result = new AccessibleState[states.size()];
 150     states.toArray(result);
 151     return result;
 152   }
 153
 154   /**
 155    * Return a localized, comma-separated string representing all states
 156    * in the set. This is in arbitrary order.
 157    *
 158    * @return the string representation
 159    * @see AccessibleBundle#toDisplayString(String, Locale)
 160    */
 161   public String toString()
 162   {
 163     int i = states.size();
 164     if (i == 0)
 165       return "";
 166     // Pre-allocate an average of 10 chars per state.
 167     StringBuffer b = new StringBuffer(i * 10);
 168     while (--i >= 0)
 169       b.append(states.get(i)).append(',');
 170     return b.substring(0, b.length() - 1);
 171   }
 172 } // class AccessibleStateSet