libjava/javax/swing/JToggleButton.java

   1 /* JToggleButton.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
  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   /**
  67    * This class provides accessibility support for the toggle button.
  68    */
  69   protected class AccessibleJToggleButton
  70     extends AccessibleAbstractButton
  71     implements ItemListener
  72   {
  73
  74     /**
  75      * Constructor for the accessible toggle button.
  76      */
  77     public AccessibleJToggleButton()
  78     {
  79       super();
  80       /* Register the accessible toggle button as a listener for item events */
  81       addItemListener(this);
  82     }
  83
  84     /**
  85      * Returns the accessible role for the toggle button.
  86      *
  87      * @return An instance of <code>AccessibleRole</code>, describing
  88      *         the role of the toggle button.
  89      */
  90     public AccessibleRole getAccessibleRole()
  91     {
  92       return AccessibleRole.TOGGLE_BUTTON;
  93     }
  94
  95     /**
  96      * Monitors the toggle button for state changes and fires accessible
  97      * property change events when they occur.
  98      *
  99      * @param event the event that occurred.
 100      */
 101     public void itemStateChanged(ItemEvent event)
 102     {
 103         /* Fire a state property change event as the button's state has changed */
 104         if (event.getStateChange() == ItemEvent.SELECTED)
 105           {
 106             /* State has changed from unselected (null) to selected */
 107             firePropertyChange(ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.SELECTED);
 108           }
 109         else
 110           {
 111             /* State has changed from selected to unselected (null) */
 112             firePropertyChange(ACCESSIBLE_STATE_PROPERTY, AccessibleState.ENABLED, null);
 113           }
 114     }
 115
 116   }
 117
 118   /**
 119    * The model handles the storage and maintenance of the state of
 120    * the toggle button.  This follows the same paradigm (the MVC
 121    * or Model-View-Controller design pattern) employed by
 122    * other Swing components, where the data associated with a component
 123    * is stored separately from the display aspects.
 124    */
 125   public static class ToggleButtonModel extends DefaultButtonModel
 126   {
 127     /**
 128      * Compatible with Sun's JDK.
 129      */
 130     private static final long serialVersionUID = -1589950750899943974L;
 131
 132     /**
 133      * Sets the pressed state of the button.  The selected state
 134      * of the button also changes follwing the button being pressed.
 135      *
 136      * @param b true if the button is pressed down.
 137      */
 138     public void setPressed(boolean b)
 139     {
 140       if (! isEnabled())
 141         return;
 142
 143       super.setPressed(b);
 144
 145       // setPressed(false) == mouse release on us,
 146       // if we were armed, we flip the selected state.
 147       if (!b && isArmed())
 148         setSelected(! isSelected());
 149     }
 150   }
 151
 152   /**
 153    * Compatible with Sun's JDK.
 154    */
 155   private static final long serialVersionUID = -3128248873429850443L;
 156
 157   /**
 158    * Constructs an unselected toggle button with no text or icon.
 159    */
 160   public JToggleButton()
 161   {
 162     this(null, null, false);
 163   }
 164
 165   /**
 166    * Constructs a toggle button using the labelling, state
 167    * and icon specified by the supplied action.
 168    *
 169    * @param a the action to use to define the properties of the button.
 170    */
 171   public JToggleButton(Action a)
 172   {
 173     this();
 174     setAction(a);
 175   }
 176
 177   /**
 178    * Constructs an unselected toggle button with the supplied icon
 179    * and no text.
 180    *
 181    * @param icon the icon to use.
 182    */
 183   public JToggleButton(Icon icon)
 184   {
 185     this(null, icon, false);
 186   }
 187
 188   /**
 189    * Constructs a toggle button with the supplied icon and state.
 190    *
 191    * @param icon the icon to use.
 192    * @param selected if true, the toggle button is initially in the
 193    *        selected state.  Otherwise, the button is unselected.
 194    */
 195   public JToggleButton(Icon icon, boolean selected)
 196   {
 197     this(null, icon, selected);
 198   }
 199
 200   /**
 201    * Constructs an unselected toggle button using the supplied text
 202    * and no icon.
 203    *
 204    * @param text the text to use.
 205    */
 206   public JToggleButton(String text)
 207   {
 208     this(text, null, false);
 209   }
 210
 211   /**
 212    * Constructs a toggle button with the supplied text and state.
 213    *
 214    * @param text the text to use.
 215    * @param selected if true, the toggle button is initially in the
 216    *        selected state.  Otherwise, the button is unselected.
 217    */
 218   public JToggleButton(String text, boolean selected)
 219   {
 220     this(text, null, selected);
 221   }
 222
 223   /**
 224    * Constructs an unselected toggle button with the supplied text
 225    * and icon.
 226    *
 227    * @param text the text to use.
 228    * @param icon the icon to use.
 229    */
 230   public JToggleButton(String text, Icon icon)
 231   {
 232     this(text, icon, false);
 233   }
 234
 235   /**
 236    * Constructs a toggle button with the supplied text, icon and state.
 237    *
 238    * @param text the text to use.
 239    * @param icon the icon to use.
 240    * @param selected if true, the toggle button is initially in the
 241    *        selected state.  Otherwise, the button is unselected.
 242    */
 243   public JToggleButton (String text, Icon icon, boolean selected)
 244   {
 245     super(text, icon);
 246
 247     horizontalAlignment = LEADING;
 248     setModel(new ToggleButtonModel());
 249     model.setSelected(selected);
 250   }
 251
 252   /**
 253    * Gets the AccessibleContext associated with this <code>JToggleButton</code>.
 254    * The context is created, if necessary.
 255    *
 256    * @return the associated context
 257    */
 258   public AccessibleContext getAccessibleContext()
 259   {
 260     /* Create the context if this is the first request */
 261     if (accessibleContext == null)
 262       {
 263         /* Create the context */
 264         accessibleContext = new AccessibleJToggleButton();
 265       }
 266     return accessibleContext;
 267   }
 268
 269   /**
 270    * Returns a string that specifies the name of the Look and Feel
 271    * class that renders this component.
 272    *
 273    * @return The Look and Feel UI class in <code>String</code> form.
 274    */
 275   public String getUIClassID()
 276   {
 277     return "ToggleButtonUI";
 278   }
 279
 280   /**
 281    * Returns a textual representation of this component for debugging.
 282    * Users should not depend on anything as regards the content or formatting
 283    * of this string, except for the fact that the returned string may never be
 284    * null (only empty).
 285    *
 286    * @return the component in <code>String</code> form for debugging.
 287    */
 288   protected  String paramString()
 289   {
 290     return "JToggleButton";
 291   }
 292
 293   /**
 294    * This method resets the toggle button's UI delegate to the default UI for
 295    * the current look and feel.
 296    */
 297   public void updateUI()
 298   {
 299     setUI((ButtonUI)UIManager.getUI(this));
 300   }
 301
 302 }
 303
 304
 305