libjava/javax/swing/JToggleButton.java

   1 /* JToggleButton.java --
   2    Copyright (C) 2002, 2004, 2005  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
  39 package javax.swing;
  40
  41 import java.awt.event.ItemEvent;
  42 import java.awt.event.ItemListener;
  43
  44 import javax.accessibility.Accessible;
  45 import javax.accessibility.AccessibleContext;
  46 import javax.accessibility.AccessibleRole;
  47 import javax.accessibility.AccessibleState;
  48 import javax.swing.plaf.ButtonUI;
  49
  50 /**
  51  * The <code>JToggleButton</code> component provides a stateful button,
  52  * which can be either selected or unselected.  This provides the basis
  53  * for the implementations of radio buttons (<code>JRadioButton</code>)
  54  * and check boxes (<code>JCheckBox</code>).
  55  *
  56  * @author Michael Koch  (konqueror@gmx.de)
  57  * @author Graydon Hoare  (graydon@redhat.com)
  58  * @author Andrew John Hughes  (gnu_andrew@member.fsf.org)
  59  * @see JRadioButton
  60  * @see JCheckBox
  61  * @since 1.2
  62  */
  63 public class JToggleButton extends AbstractButton implements Accessible
  64 {
  65   /**
  66    * This class provides accessibility support for the toggle button.
  67    */
  68   protected class AccessibleJToggleButton
  69     extends AccessibleAbstractButton
  70     implements ItemListener
  71   {
  72
  73     /**
  74      * Constructor for the accessible toggle button.
  75      */
  76     public AccessibleJToggleButton()
  77     {
  78       super();
  79       /* Register the accessible toggle button as a listener for item events */
  80       addItemListener(this);
  81     }
  82
  83     /**
  84      * Returns the accessible role for the toggle button.
  85      *
  86      * @return An instance of <code>AccessibleRole</code>, describing
  87      *         the role of the toggle button.
  88      */
  89     public AccessibleRole getAccessibleRole()
  90     {
  91       return AccessibleRole.TOGGLE_BUTTON;
  92     }
  93
  94     /**
  95      * Monitors the toggle button for state changes and fires accessible
  96      * property change events when they occur.
  97      *
  98      * @param event the event that occurred.
  99      */
 100     public void itemStateChanged(ItemEvent event)
 101     {
 102         /* Fire a state property change event as the button's state has changed */
 103         if (event.getStateChange() == ItemEvent.SELECTED)
 104           {
 105             /* State has changed from unselected (null) to selected */
 106             firePropertyChange(ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.SELECTED);
 107           }
 108         else
 109           {
 110             /* State has changed from selected to unselected (null) */
 111             firePropertyChange(ACCESSIBLE_STATE_PROPERTY, AccessibleState.ENABLED, null);
 112           }
 113     }
 114
 115   }
 116
 117   /**
 118    * The model handles the storage and maintenance of the state of
 119    * the toggle button.  This follows the same paradigm (the MVC
 120    * or Model-View-Controller design pattern) employed by
 121    * other Swing components, where the data associated with a component
 122    * is stored separately from the display aspects.
 123    */
 124   public static class ToggleButtonModel extends DefaultButtonModel
 125   {
 126     /**
 127      * Compatible with Sun's JDK.
 128      */
 129     private static final long serialVersionUID = -1589950750899943974L;
 130
 131     /**
 132      * Sets the pressed state of the button.  The selected state
 133      * of the button also changes follwing the button being pressed.
 134      *
 135      * @param b true if the button is pressed down.
 136      */
 137     public void setPressed(boolean b)
 138     {
 139       if (! isEnabled())
 140         return;
 141
 142       super.setPressed(b);
 143
 144       // setPressed(false) == mouse release on us,
 145       // if we were armed, we flip the selected state.
 146       if (!b && isArmed())
 147         setSelected(! isSelected());
 148     }
 149   }
 150
 151   /**
 152    * Compatible with Sun's JDK.
 153    */
 154   private static final long serialVersionUID = -3128248873429850443L;
 155
 156   /**
 157    * Constructs an unselected toggle button with no text or icon.
 158    */
 159   public JToggleButton()
 160   {
 161     this(null, null, false);
 162   }
 163
 164   /**
 165    * Constructs a toggle button using the labelling, state
 166    * and icon specified by the supplied action.
 167    *
 168    * @param a the action to use to define the properties of the button.
 169    */
 170   public JToggleButton(Action a)
 171   {
 172     this();
 173     setAction(a);
 174   }
 175
 176   /**
 177    * Constructs an unselected toggle button with the supplied icon
 178    * and no text.
 179    *
 180    * @param icon the icon to use.
 181    */
 182   public JToggleButton(Icon icon)
 183   {
 184     this(null, icon, false);
 185   }
 186
 187   /**
 188    * Constructs a toggle button with the supplied icon and state.
 189    *
 190    * @param icon the icon to use.
 191    * @param selected if true, the toggle button is initially in the
 192    *        selected state.  Otherwise, the button is unselected.
 193    */
 194   public JToggleButton(Icon icon, boolean selected)
 195   {
 196     this(null, icon, selected);
 197   }
 198
 199   /**
 200    * Constructs an unselected toggle button using the supplied text
 201    * and no icon.
 202    *
 203    * @param text the text to use.
 204    */
 205   public JToggleButton(String text)
 206   {
 207     this(text, null, false);
 208   }
 209
 210   /**
 211    * Constructs a toggle button with the supplied text and state.
 212    *
 213    * @param text the text to use.
 214    * @param selected if true, the toggle button is initially in the
 215    *        selected state.  Otherwise, the button is unselected.
 216    */
 217   public JToggleButton(String text, boolean selected)
 218   {
 219     this(text, null, selected);
 220   }
 221
 222   /**
 223    * Constructs an unselected toggle button with the supplied text
 224    * and icon.
 225    *
 226    * @param text the text to use.
 227    * @param icon the icon to use.
 228    */
 229   public JToggleButton(String text, Icon icon)
 230   {
 231     this(text, icon, false);
 232   }
 233
 234   /**
 235    * Constructs a toggle button with the supplied text, icon and state.
 236    *
 237    * @param text the text to use.
 238    * @param icon the icon to use.
 239    * @param selected if true, the toggle button is initially in the
 240    *        selected state.  Otherwise, the button is unselected.
 241    */
 242   public JToggleButton (String text, Icon icon, boolean selected)
 243   {
 244     super(text, icon);
 245
 246     horizontalAlignment = LEADING;
 247     setModel(new ToggleButtonModel());
 248     model.setSelected(selected);
 249   }
 250
 251   /**
 252    * Gets the AccessibleContext associated with this <code>JToggleButton</code>.
 253    * The context is created, if necessary.
 254    *
 255    * @return the associated context
 256    */
 257   public AccessibleContext getAccessibleContext()
 258   {
 259     /* Create the context if this is the first request */
 260     if (accessibleContext == null)
 261       {
 262         /* Create the context */
 263         accessibleContext = new AccessibleJToggleButton();
 264       }
 265     return accessibleContext;
 266   }
 267
 268   /**
 269    * Returns a string that specifies the name of the Look and Feel
 270    * class that renders this component.
 271    *
 272    * @return The Look and Feel UI class in <code>String</code> form.
 273    */
 274   public String getUIClassID()
 275   {
 276     return "ToggleButtonUI";
 277   }
 278
 279   /**
 280    * Returns a textual representation of this component for debugging.
 281    * Users should not depend on anything as regards the content or formatting
 282    * of this string, except for the fact that the returned string may never be
 283    * null (only empty).
 284    *
 285    * @return the component in <code>String</code> form for debugging.
 286    */
 287   protected  String paramString()
 288   {
 289     return "JToggleButton";
 290   }
 291
 292   /**
 293    * This method resets the toggle button's UI delegate to the default UI for
 294    * the current look and feel.
 295    */
 296   public void updateUI()
 297   {
 298     setUI((ButtonUI)UIManager.getUI(this));
 299   }
 300
 301 }
 302
 303
 304