libjava/javax/swing/DefaultComboBoxModel.java

   1 /* DefaultComboBoxModel.java --
   2    Copyright (C) 2002, 2004 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., 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.swing;
  39
  40 import java.io.Serializable;
  41 import java.util.Arrays;
  42 import java.util.Vector;
  43
  44
  45 /**
  46  * DefaultComboBoxModel is a data model for JComboBox. This model keeps track
  47  * of elements contained in the JComboBox as well as the current combo box
  48  * selection. Whenever selection in the JComboBox changes, the ComboBoxModel
  49  * will fire ListDataEvents to ComboBox's ListDataListeners.
  50  *
  51  * @author Andrew Selkirk
  52  * @author Olga Rodimina
  53  * @author Robert Schuster
  54  * @version 1.0
  55  */
  56 public class DefaultComboBoxModel extends AbstractListModel
  57   implements MutableComboBoxModel, Serializable
  58 {
  59   private static final long serialVersionUID = 6698657703676921904L;
  60
  61   /**
  62    * List containing items in the combo box
  63    */
  64   private Vector list;
  65
  66   /**
  67    * Currently selected item in the combo box list
  68    */
  69   private Object selectedItem = null;
  70
  71   /**
  72    * Constructor DefaultComboBoxModel. Create empty JComboBox.
  73    */
  74   public DefaultComboBoxModel()
  75   {
  76     list = new Vector();
  77   }
  78
  79   /**
  80    * Constructs new DefaultComboBoxModel object and initializes its item list
  81    * to values in the given array.
  82    *
  83    * @param items array containing items of the combo box.
  84    */
  85   public DefaultComboBoxModel(Object[] items)
  86   {
  87     list = new Vector(Arrays.asList(items));
  88   }
  89
  90   /**
  91    * Consturcts new DefaultComboBoxModel object and initializes its item list
  92    * to values in the given vector.
  93    *
  94    * @param vector Vector containing items for this combo box.
  95    */
  96   public DefaultComboBoxModel(Vector vector)
  97   {
  98     this.list = vector;
  99   }
 100
 101   /**
 102    * This method adds element to the combo box list. It fires ListDataEvent
 103    * indicating that component was added to the combo box  to all of the
 104    * JComboBox's registered ListDataListeners.
 105    *
 106    * @param object item to add to the combo box list
 107    */
 108   public void addElement(Object object)
 109   {
 110     list.add(object);
 111     fireIntervalAdded(this, list.size(), list.size());
 112   }
 113
 114   /**
 115    * This method removes element at the specified index from the combo box
 116    * list. It fires ListDataEvent indicating that component was removed from
 117    * the combo box list to all of the JComboBox's registered
 118    * ListDataListeners.
 119    *
 120    * @param index index specifying location of the element to remove in the
 121    *        combo box list.
 122    */
 123   public void removeElementAt(int index)
 124   {
 125     list.remove(index);
 126     fireIntervalRemoved(this, index, index);
 127   }
 128
 129   /**
 130    * This method inserts given object to the combo box list at the specified
 131    * index. It fires ListDataEvent indicating that component was inserted to
 132    * the combo box list to all of the JComboBox's registered
 133    * ListDataListeners.
 134    *
 135    * @param object element to insert
 136    * @param index index specifing position in the list where given element
 137    *        should be inserted.
 138    */
 139   public void insertElementAt(Object object, int index)
 140   {
 141     list.insertElementAt(object, index);
 142     fireIntervalAdded(this, index, index);
 143   }
 144
 145   /**
 146    * Removes given object from the combo box list. It fires ListDataEvent
 147    * indicating that component was removed from the combo box list to all of
 148    * the JComboBox's registered ListDataListeners.
 149    *
 150    * @param object Element that will be removed from the combo box list
 151    */
 152   public void removeElement(Object object)
 153   {
 154     int index = getIndexOf(object);
 155     if (index != -1)
 156       removeElementAt(index);
 157   }
 158
 159   /**
 160    * Removes all the items from the JComboBox's item list. It fires
 161    * ListDataEvent indicating that all the elements were removed from the
 162    * combo box list to all of the JComboBox's registered ListDataListeners.
 163    */
 164   public void removeAllElements()
 165   {
 166     int listSize = getSize();
 167     list.clear();
 168     fireIntervalAdded(this, 0, listSize - 1);
 169   }
 170
 171   /**
 172    * Returns number of items in the combo box list
 173    *
 174    * @return number of items in the combo box list
 175    */
 176   public int getSize()
 177   {
 178     return list.size();
 179   }
 180
 181   /**
 182    * Selects given object in the combo box list. This method fires
 183    * ListDataEvent to all registered ListDataListeners of the JComboBox. The
 184    * start and end index of the event is set to -1 to indicate combo box's
 185    * selection has changed, and not its contents.
 186    *
 187    * <p>If the given object is not contained in the combo box list then nothing
 188    * happens.</p>
 189    *
 190    * @param object item to select in the JComboBox
 191    */
 192   public void setSelectedItem(Object object)
 193   {
 194
 195     /* Updates the selected item only if the given object
 196      * is null or in the list (this is how the JDK behaves).
 197      */
 198     if(object == null || list.contains(object)) {
 199         selectedItem = object;
 200         fireContentsChanged(this, -1, -1);
 201     }
 202
 203   }
 204
 205   /**
 206    * Returns currently selected item in the combo box list
 207    *
 208    * @return currently selected item in the combo box list
 209    */
 210   public Object getSelectedItem()
 211   {
 212     return selectedItem;
 213   }
 214
 215   /**
 216    * Returns element in the combo box list located at the given index
 217    *
 218    * @param index specifying location of the element in the list
 219    *
 220    * @return return element in the combo box list located at the given index
 221    */
 222   public Object getElementAt(int index)
 223   {
 224     return list.elementAt(index);
 225   }
 226
 227   /**
 228    * Returns index of the specified object in the combo box list.
 229    *
 230    * @param object element to look for in the combo box list .
 231    *
 232    * @return Index specifying position of the specified element in combo box
 233    *         list.
 234    */
 235   public int getIndexOf(Object object)
 236   {
 237     return list.indexOf(object);
 238   }
 239 }