libjava/javax/swing/ButtonGroup.java

   1 /* ButtonGroup.java --
   2    Copyright (C) 2002 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.Enumeration;
  42 import java.util.Vector;
  43
  44
  45 public class ButtonGroup
  46   implements Serializable
  47 {
  48   private static final long serialVersionUID = 4259076101881721375L;
  49
  50   /**
  51    * The buttons added to this button group.
  52    */
  53   protected Vector buttons = new Vector();
  54
  55   /**
  56    * The currently selected button model.
  57    */
  58   ButtonModel sel;
  59
  60   /**
  61    * Creates a new button group.
  62    */
  63   public ButtonGroup()
  64   {
  65   }
  66
  67   /**
  68    * Adds a button to this group.
  69    *
  70    * @param b the button to add
  71    */
  72   public void add(AbstractButton b)
  73   {
  74     b.getModel().setGroup(this);
  75     buttons.addElement(b);
  76   }
  77
  78   /**
  79    * Removed a given button from this group.
  80    *
  81    * @param b the button to remove
  82    */
  83   public void remove(AbstractButton b)
  84   {
  85     b.getModel().setGroup(null);
  86     buttons.removeElement(b);
  87   }
  88
  89   /**
  90    * Returns the currently added buttons.
  91    *
  92    * @return <code>Enumeration</code> over all added buttons
  93    */
  94   public Enumeration getElements()
  95   {
  96     return buttons.elements();
  97   }
  98
  99   /**
 100    * Returns the currently selected button model.
 101    *
 102    * @return the currently selected button model,
 103    * null if none was selected yet
 104    */
 105   public ButtonModel getSelection()
 106   {
 107     return sel;
 108   }
 109
 110   AbstractButton FindButton(ButtonModel m)
 111   {
 112     for (int i = 0;i < buttons.size(); i++)
 113       {
 114         AbstractButton a = (AbstractButton) buttons.get(i);
 115         if (a.getModel() == m)
 116           return a;
 117       }
 118     return null;
 119   }
 120
 121   /**
 122    * Sets the currently selected button model. Only one button of a group
 123    * can be selected at a time.
 124    *
 125    * @param m the model to select
 126    * @param b true if this button is to be selected, false otherwise
 127    */
 128   public void setSelected(ButtonModel m, boolean b)
 129   {
 130     if ((m == sel) && (b == true))
 131       {
 132         // clicked on same item twice.
 133         System.out.println("PRESSED TWICE:" + m + ", sel=" + sel);
 134         return;
 135       }
 136
 137     if (sel != null)
 138       {
 139         System.out.println("DESELECTING: " + sel);
 140         sel.setSelected(! b);
 141
 142         AbstractButton but = FindButton(sel);
 143         if (but != null)
 144           {
 145             System.out.println("REPAINT-REQUEST: " + but.text);
 146             //but.revalidate();
 147             but.repaint();
 148           }
 149       }
 150     else
 151       System.out.println("NO SELECTION YET");
 152
 153     sel = m;
 154   }
 155
 156   /**
 157    * Checks if the given <code>ButtonModel</code> is selected
 158    * in this button group.
 159    *
 160    * @return true of given <code>ButtonModel</code> is selected,
 161    * false otherwise
 162    */
 163   public boolean isSelected(ButtonModel m)
 164   {
 165     return m == sel;
 166   }
 167
 168   /**
 169    * Return the number of buttons in this button group.
 170    *
 171    * @return the number of buttons
 172    *
 173    * @since 1.3
 174    */
 175   public int getButtonCount()
 176   {
 177     return buttons.size();
 178   }
 179 }