001/* JToggleButton.java -- 002 Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package javax.swing; 040 041import java.awt.event.ActionEvent; 042import java.awt.event.ItemEvent; 043import java.awt.event.ItemListener; 044 045import javax.accessibility.Accessible; 046import javax.accessibility.AccessibleContext; 047import javax.accessibility.AccessibleRole; 048import javax.accessibility.AccessibleState; 049import javax.swing.plaf.ButtonUI; 050 051/** 052 * The <code>JToggleButton</code> component provides a stateful button, 053 * which can be either selected or unselected. This provides the basis 054 * for the implementations of radio buttons (<code>JRadioButton</code>) 055 * and check boxes (<code>JCheckBox</code>). 056 * 057 * @author Michael Koch (konqueror@gmx.de) 058 * @author Graydon Hoare (graydon@redhat.com) 059 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 060 * @see JRadioButton 061 * @see JCheckBox 062 * @since 1.2 063 */ 064public class JToggleButton extends AbstractButton implements Accessible 065{ 066 /** 067 * This class provides accessibility support for the toggle button. 068 */ 069 protected class AccessibleJToggleButton 070 extends AccessibleAbstractButton 071 implements ItemListener 072 { 073 private static final long serialVersionUID = -8652952712161229225L; 074 075 /** 076 * Constructor for the accessible toggle button. 077 */ 078 public AccessibleJToggleButton() 079 { 080 super(); 081 /* Register the accessible toggle button as a listener for item events */ 082 addItemListener(this); 083 } 084 085 /** 086 * Returns the accessible role for the toggle button. 087 * 088 * @return An instance of <code>AccessibleRole</code>, describing 089 * the role of the toggle button. 090 */ 091 public AccessibleRole getAccessibleRole() 092 { 093 return AccessibleRole.TOGGLE_BUTTON; 094 } 095 096 /** 097 * Monitors the toggle button for state changes and fires accessible 098 * property change events when they occur. 099 * 100 * @param event the event that occurred. 101 */ 102 public void itemStateChanged(ItemEvent event) 103 { 104 /* Fire a state property change event as the button's state has changed */ 105 if (event.getStateChange() == ItemEvent.SELECTED) 106 { 107 /* State has changed from unselected (null) to selected */ 108 firePropertyChange(ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.SELECTED); 109 } 110 else 111 { 112 /* State has changed from selected to unselected (null) */ 113 firePropertyChange(ACCESSIBLE_STATE_PROPERTY, AccessibleState.ENABLED, null); 114 } 115 } 116 117 } 118 119 /** 120 * The model handles the storage and maintenance of the state of 121 * the toggle button. This follows the same paradigm (the MVC 122 * or Model-View-Controller design pattern) employed by 123 * other Swing components, where the data associated with a component 124 * is stored separately from the display aspects. 125 */ 126 public static class ToggleButtonModel extends DefaultButtonModel 127 { 128 /** 129 * Compatible with Sun's JDK. 130 */ 131 private static final long serialVersionUID = -1589950750899943974L; 132 133 /** 134 * Sets the pressed state of the button. The selected state 135 * of the button also changes follwing the button being pressed. 136 * 137 * @param p true if the button is pressed down. 138 */ 139 public void setPressed(boolean p) 140 { 141 // cannot change PRESSED state unless button is enabled 142 if (! isEnabled()) 143 return; 144 145 // if this call does not represent a CHANGE in state, then return 146 if ((p && isPressed()) || (!p && !isPressed())) 147 return; 148 149 // The JDK first fires events in the following order: 150 // 1. ChangeEvent for selected 151 // 2. ChangeEvent for pressed 152 // 3. ActionEvent 153 // So do we. 154 155 // setPressed(false) == mouse release on us, 156 // if we were armed, we flip the selected state. 157 if (!p && isArmed()) 158 { 159 setSelected(! isSelected()); 160 } 161 162 // make the change 163 if (p) 164 stateMask = stateMask | PRESSED; 165 else 166 stateMask = stateMask & (~PRESSED); 167 168 // notify interested ChangeListeners 169 fireStateChanged(); 170 171 if (!p && isArmed()) 172 { 173 fireActionPerformed(new ActionEvent(this, 174 ActionEvent.ACTION_PERFORMED, 175 actionCommand)); 176 } 177 } 178 179 /** 180 * Checks if the button is selected. 181 * 182 * @return <code>true</code> if the button is selected. 183 */ 184 public boolean isSelected() 185 { 186 return super.isSelected(); 187 } 188 189 /** 190 * Sets the selected state of the button. 191 * 192 * @param b true if button is selected 193 */ 194 public void setSelected(boolean b) 195 { 196 super.setSelected(b); 197 } 198 } 199 200 /** 201 * Compatible with Sun's JDK. 202 */ 203 private static final long serialVersionUID = -3128248873429850443L; 204 205 /** 206 * Constructs an unselected toggle button with no text or icon. 207 */ 208 public JToggleButton() 209 { 210 this(null, null, false); 211 } 212 213 /** 214 * Constructs a toggle button using the labelling, state 215 * and icon specified by the supplied action. 216 * 217 * @param a the action to use to define the properties of the button. 218 */ 219 public JToggleButton(Action a) 220 { 221 this(); 222 setAction(a); 223 } 224 225 /** 226 * Constructs an unselected toggle button with the supplied icon 227 * and no text. 228 * 229 * @param icon the icon to use. 230 */ 231 public JToggleButton(Icon icon) 232 { 233 this(null, icon, false); 234 } 235 236 /** 237 * Constructs a toggle button with the supplied icon and state. 238 * 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(Icon icon, boolean selected) 244 { 245 this(null, icon, selected); 246 } 247 248 /** 249 * Constructs an unselected toggle button using the supplied text 250 * and no icon. 251 * 252 * @param text the text to use. 253 */ 254 public JToggleButton(String text) 255 { 256 this(text, null, false); 257 } 258 259 /** 260 * Constructs a toggle button with the supplied text and state. 261 * 262 * @param text the text to use. 263 * @param selected if true, the toggle button is initially in the 264 * selected state. Otherwise, the button is unselected. 265 */ 266 public JToggleButton(String text, boolean selected) 267 { 268 this(text, null, selected); 269 } 270 271 /** 272 * Constructs an unselected toggle button with the supplied text 273 * and icon. 274 * 275 * @param text the text to use. 276 * @param icon the icon to use. 277 */ 278 public JToggleButton(String text, Icon icon) 279 { 280 this(text, icon, false); 281 } 282 283 /** 284 * Constructs a toggle button with the supplied text, icon and state. 285 * 286 * @param text the text to use. 287 * @param icon the icon to use. 288 * @param selected if true, the toggle button is initially in the 289 * selected state. Otherwise, the button is unselected. 290 */ 291 public JToggleButton (String text, Icon icon, boolean selected) 292 { 293 super(); 294 setModel(new ToggleButtonModel()); 295 init(text, icon); 296 model.setSelected(selected); 297 setAlignmentX(LEFT_ALIGNMENT); 298 } 299 300 /** 301 * Gets the AccessibleContext associated with this <code>JToggleButton</code>. 302 * The context is created, if necessary. 303 * 304 * @return the associated context 305 */ 306 public AccessibleContext getAccessibleContext() 307 { 308 /* Create the context if this is the first request */ 309 if (accessibleContext == null) 310 { 311 /* Create the context */ 312 accessibleContext = new AccessibleJToggleButton(); 313 } 314 return accessibleContext; 315 } 316 317 /** 318 * Returns a string that specifies the name of the Look and Feel 319 * class that renders this component. 320 * 321 * @return The Look and Feel UI class in <code>String</code> form. 322 */ 323 public String getUIClassID() 324 { 325 return "ToggleButtonUI"; 326 } 327 328 /** 329 * Returns a textual representation of this component for debugging. 330 * Users should not depend on anything as regards the content or formatting 331 * of this string, except for the fact that the returned string may never be 332 * null (only empty). 333 * 334 * @return the component in <code>String</code> form for debugging. 335 */ 336 protected String paramString() 337 { 338 return super.paramString(); 339 } 340 341 /** 342 * This method resets the toggle button's UI delegate to the default UI for 343 * the current look and feel. 344 */ 345 public void updateUI() 346 { 347 setUI((ButtonUI)UIManager.getUI(this)); 348 } 349 350} 351 352 353