001/* JCheckBoxMenuItem.java --
002 Copyright (C) 2002, 2004, 2006, Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014 General Public License for more details.
015
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017 along with GNU Classpath; see the file COPYING.  If not, write to the
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019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library.  Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
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033 or based on this library.  If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so.  If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039package javax.swing;
040
041import javax.accessibility.Accessible;
042import javax.accessibility.AccessibleContext;
043import javax.accessibility.AccessibleRole;
044
045/**
046 * A menu item that displays a checkbox. Its behaviour is very similar to
047 * {@link JCheckBox}. Just like the <code>JCheckBox</code>, user can check
048 * and uncheck this menu item by clicking on it. Also
049 * {@link AbstractButton#setSelected} and {@link #setState} can be use used for
050 * the same purpose. <code>JCheckBoxMenuItem</code> uses
051 * <code>ToggleButtonModel</code> to keep track of its selection.
052 *
053 * @author original author unknown
054 */
055public class JCheckBoxMenuItem
056    extends JMenuItem
057    implements SwingConstants, Accessible
058{
059  private static final long serialVersionUID = - 6676402307973384715L;
060
061  /** name for the UI delegate for this menuItem. */
062  private static final String uiClassID = "CheckBoxMenuItemUI";
063
064  /** Indicates whether this menu item is checked. */
065  private boolean state;
066
067  /**
068   * This array contains text of this menu item if this menu item is in checked
069   * state and null it is not.
070   */
071  private Object[] selectedObjects = new Object[1];
072
073  /**
074   * Creates a new JCheckBoxMenuItem object.
075   */
076  public JCheckBoxMenuItem()
077  {
078    this(null, null);
079  }
080
081  /**
082   * Creates a new JCheckBoxMenuItem with given icon
083   *
084   * @param icon Icon for this menu item
085   */
086  public JCheckBoxMenuItem(Icon icon)
087  {
088    this(null, icon);
089  }
090
091  /**
092   * Creates a new JCheckBoxMenuItem with given label
093   *
094   * @param text Label for this menu item
095   */
096  public JCheckBoxMenuItem(String text)
097  {
098    this(text, null);
099  }
100
101  /**
102   * Creates a new JCheckBoxMenuItem using given action
103   *
104   * @param action Action for this menu item.
105   */
106  public JCheckBoxMenuItem(Action action)
107  {
108    this();
109    setAction(action);
110  }
111
112  /**
113   * Creates a new JCheckBoxMenuItem object with given label and icon
114   *
115   * @param text Label for this menu item
116   * @param icon Icon for this menu item
117   */
118  public JCheckBoxMenuItem(String text, Icon icon)
119  {
120    this(text, icon, false);
121  }
122
123  /**
124   * Creates a new JCheckBoxMenuItem object using specified label and marked as
125   * checked if given 'state' is true.
126   *
127   * @param text Label for this menu item
128   * @param state <code>true</code> if this item should be in checked state
129   *          and <code>false</code> otherwise
130   */
131  public JCheckBoxMenuItem(String text, boolean state)
132  {
133    this(text, null, state);
134  }
135
136  /**
137   * Creates a new JCheckBoxMenuItem object with given label, icon, and marked
138   * as checked if given 'state' is true.
139   *
140   * @param text Label for this menu item
141   * @param icon icon for this menu item
142   * @param state <code>true</code> if this item should be in checked state
143   *          and false otherwise
144   */
145  public JCheckBoxMenuItem(String text, Icon icon, boolean state)
146  {
147    super(text, icon);
148    setModel(new JToggleButton.ToggleButtonModel());
149    this.state = state;
150    if (state == true)
151      this.setSelected(true);
152    setFocusable(false);
153  }
154
155  /**
156   * This method returns a name to identify which look and feel class will be
157   * the UI delegate for the menuItem.
158   *
159   * @return The Look and Feel classID. "JCheckBoxMenuItemUI"
160   */
161  public String getUIClassID()
162  {
163    return uiClassID;
164  }
165
166  /**
167   * Returns checked state for this check box menu item.
168   *
169   * @return Returns true if this menu item is in checked state and false
170   *         otherwise.
171   */
172  public boolean getState()
173  {
174    return state;
175  }
176
177  /**
178   * Sets state for this check box menu item. If given 'state' is true, then
179   * mark menu item as checked, and uncheck this menu item otherwise.
180   *
181   * @param state new state for this menu item
182   */
183  public synchronized void setState(boolean state)
184  {
185    this.state = state;
186  }
187
188  /**
189   * This method returns array containing label of this menu item if it is
190   * selected and null otherwise.
191   *
192   * @return Array containing label of this menu item if this menu item is
193   *         selected or null otherwise.
194   */
195  public Object[] getSelectedObjects()
196  {
197    if (state == true)
198      selectedObjects[0] = this.getText();
199    else
200      selectedObjects[0] = null;
201
202    return selectedObjects;
203  }
204
205  /**
206   * This method overrides JComponent.requestFocus with an empty implementation,
207   * since JCheckBoxMenuItems should not receive focus in general.
208   */
209  public void requestFocus()
210  {
211    // Should do nothing here
212  }
213
214  /**
215   * Returns a string describing the attributes for the
216   * <code>JCheckBoxMenuItem</code> component, for use in debugging. The
217   * return value is guaranteed to be non-<code>null</code>, but the format
218   * of the string may vary between implementations.
219   *
220   * @return A string describing the attributes of the
221   *         <code>JCheckBoxMenuItem</code>.
222   */
223  protected String paramString()
224  {
225    // calling super seems to be sufficient to match the reference
226    // implementation here...
227    return super.paramString();
228  }
229
230  /**
231   * Returns the object that provides accessibility features for this
232   * <code>JCheckBoxMenuItem</code> component.
233   *
234   * @return The accessible context (an instance of
235   *         {@link AccessibleJCheckBoxMenuItem}).
236   */
237  public AccessibleContext getAccessibleContext()
238  {
239    if (accessibleContext == null)
240      accessibleContext = new AccessibleJCheckBoxMenuItem();
241
242    return accessibleContext;
243  }
244
245  /**
246   * Provides the accessibility features for the <code>JCheckBoxMenuItem</code>
247   * component.
248   *
249   * @see JCheckBoxMenuItem#getAccessibleContext()
250   */
251  protected class AccessibleJCheckBoxMenuItem
252      extends AccessibleJMenuItem
253  {
254    private static final long serialVersionUID = 1079958073579370777L;
255
256    /**
257     * Creates a new <code>AccessibleJCheckBoxMenuItem</code> instance.
258     */
259    protected AccessibleJCheckBoxMenuItem()
260    {
261      // Nothing to do here.
262    }
263
264    /**
265     * Returns the accessible role for the <code>JCheckBoxMenuItem</code>
266     * component.
267     *
268     * @return {@link AccessibleRole#CHECK_BOX}.
269     */
270    public AccessibleRole getAccessibleRole()
271    {
272      return AccessibleRole.CHECK_BOX;
273    }
274  }
275}