/*

 * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.swing;

import java.util.EventListener;

import java.awt.*;

import java.awt.event.*;

import java.awt.image.*;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

import javax.swing.plaf.*;

import javax.accessibility.*;

/**

 * A menu item that can be selected or deselected. If selected, the menu

 * item typically appears with a checkmark next to it. If unselected or

 * deselected, the menu item appears without a checkmark. Like a regular

 * menu item, a check box menu item can have either text or a graphic

 * icon associated with it, or both.

 * <p>

 * Either <code>isSelected</code>/<code>setSelected</code> or

 * <code>getState</code>/<code>setState</code> can be used

 * to determine/specify the menu item's selection state. The

 * preferred methods are <code>isSelected</code> and

 * <code>setSelected</code>, which work for all menus and buttons.

 * The <code>getState</code> and <code>setState</code> methods exist for

 * compatibility with other component sets.

 * <p>

 * Menu items can be configured, and to some degree controlled, by

 * <code><a href="Action.html">Action</a></code>s.  Using an

 * <code>Action</code> with a menu item has many benefits beyond directly

 * configuring a menu item.  Refer to <a href="Action.html#buttonActions">

 * Swing Components Supporting <code>Action</code></a> for more

 * details, and you can find more information in <a

 * href="http://java.sun.com/docs/books/tutorial/uiswing/misc/action.html">How

 * to Use Actions</a>, a section in <em>The Java Tutorial</em>.

 * <p>

 * For further information and examples of using check box menu items,

 * see <a

 href="http://java.sun.com/docs/books/tutorial/uiswing/components/menu.html">How to Use Menus</a>,

 * a section in <em>The Java Tutorial.</em>

 * <p>

 * <strong>Warning:</strong> Swing is not thread safe. For more

 * information see <a

 * href="package-summary.html#threading">Swing's Threading

 * Policy</a>.

 * <p>

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @beaninfo

 *   attribute: isContainer false

 * description: A menu item which can be selected or deselected.

 *

 * @author Georges Saab

 * @author David Karlton

 */

public class JCheckBoxMenuItem extends JMenuItem implements SwingConstants,

        Accessible

{

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "CheckBoxMenuItemUI";

    /**

     * Creates an initially unselected check box menu item with no set text or icon.

     */

    public JCheckBoxMenuItem() {

        this(null, null, false);

    }

    /**

     * Creates an initially unselected check box menu item with an icon.

     *

     * @param icon the icon of the CheckBoxMenuItem.

     */

    public JCheckBoxMenuItem(Icon icon) {

        this(null, icon, false);

    }

    /**

     * Creates an initially unselected check box menu item with text.

     *

     * @param text the text of the CheckBoxMenuItem

     */

    public JCheckBoxMenuItem(String text) {

        this(text, null, false);

    }

    /**

     * Creates a menu item whose properties are taken from the

     * Action supplied.

     *

     * @since 1.3

     */

    public JCheckBoxMenuItem(Action a) {

        this();

        setAction(a);

    }

    /**

     * Creates an initially unselected check box menu item with the specified text and icon.

     *

     * @param text the text of the CheckBoxMenuItem

     * @param icon the icon of the CheckBoxMenuItem

     */

    public JCheckBoxMenuItem(String text, Icon icon) {

        this(text, icon, false);

    }

    /**

     * Creates a check box menu item with the specified text and selection state.

     *

     * @param text the text of the check box menu item.

     * @param b the selected state of the check box menu item

     */

    public JCheckBoxMenuItem(String text, boolean b) {

        this(text, null, b);

    }

    /**

     * Creates a check box menu item with the specified text, icon, and selection state.

     *

     * @param text the text of the check box menu item

     * @param icon the icon of the check box menu item

     * @param b the selected state of the check box menu item

     */

    public JCheckBoxMenuItem(String text, Icon icon, boolean b) {

        super(text, icon);

        setModel(new JToggleButton.ToggleButtonModel());

        setSelected(b);

        setFocusable(false);

    }

    /**

     * Returns the name of the L&F class

     * that renders this component.

     *

     * @return "CheckBoxMenuItemUI"

     * @see JComponent#getUIClassID

     * @see UIDefaults#getUI

     */

    public String getUIClassID() {

        return uiClassID;

    }

     /**

      * Returns the selected-state of the item. This method

      * exists for AWT compatibility only.  New code should

      * use isSelected() instead.

      *

      * @return true  if the item is selected

      */

    public boolean getState() {

        return isSelected();

    }

    /**

     * Sets the selected-state of the item. This method

     * exists for AWT compatibility only.  New code should

     * use setSelected() instead.

     *

     * @param b  a boolean value indicating the item's

     *           selected-state, where true=selected

     * @beaninfo

     * description: The selection state of the check box menu item

     *      hidden: true

     */

    public synchronized void setState(boolean b) {

        setSelected(b);

    }

    /**

     * Returns an array (length 1) containing the check box menu item

     * label or null if the check box is not selected.

     *

     * @return an array containing one Object -- the text of the menu item

     *         -- if the item is selected; otherwise null

     */

    public Object[] getSelectedObjects() {

        if (isSelected() == false)

            return null;

        Object[] selectedObjects = new Object[1];

        selectedObjects[0] = getText();

        return selectedObjects;

    }

    /**

     * See readObject() and writeObject() in JComponent for more

     * information about serialization in Swing.

     */

    private void writeObject(ObjectOutputStream s) throws IOException {

        s.defaultWriteObject();

        if (getUIClassID().equals(uiClassID)) {

            byte count = JComponent.getWriteObjCounter(this);

            JComponent.setWriteObjCounter(this, --count);

            if (count == 0 && ui != null) {

                ui.installUI(this);

            }

        }

    }

    /**

     * Returns a string representation of this JCheckBoxMenuItem. This method

     * is intended to be used only for debugging purposes, and the

     * content and format of the returned string may vary between

     * implementations. The returned string may be empty but may not

     * be <code>null</code>.

     *

     * @return  a string representation of this JCheckBoxMenuItem.

     */

    protected String paramString() {

        return super.paramString();

    }

    /**

     * Overriden to return true, JCheckBoxMenuItem supports

     * the selected state.

     */

    boolean shouldUpdateSelectedStateFromAction() {

        return true;

    }

/////////////////

// Accessibility support

////////////////

    /**

     * Gets the AccessibleContext associated with this JCheckBoxMenuItem.

     * For JCheckBoxMenuItems, the AccessibleContext takes the form of an

     * AccessibleJCheckBoxMenuItem.

     * A new AccessibleJCheckBoxMenuItem instance is created if necessary.

     *

     * @return an AccessibleJCheckBoxMenuItem that serves as the

     *         AccessibleContext of this AccessibleJCheckBoxMenuItem

     */

    public AccessibleContext getAccessibleContext() {

        if (accessibleContext == null) {

            accessibleContext = new AccessibleJCheckBoxMenuItem();

        }

        return accessibleContext;

    }

    /**

     * This class implements accessibility support for the

     * <code>JCheckBoxMenuItem</code> class.  It provides an implementation

     * of the Java Accessibility API appropriate to checkbox menu item

     * user-interface elements.

     * <p>

     * <strong>Warning:</strong>

     * Serialized objects of this class will not be compatible with

     * future Swing releases. The current serialization support is

     * appropriate for short term storage or RMI between applications running

     * the same version of Swing.  As of 1.4, support for long term storage

     * of all JavaBeans<sup><font size="-2">TM</font></sup>

     * has been added to the <code>java.beans</code> package.

     * Please see {@link java.beans.XMLEncoder}.

     */

    protected class AccessibleJCheckBoxMenuItem extends AccessibleJMenuItem {

        /**

         * Get the role of this object.

         *

         * @return an instance of AccessibleRole describing the role of the

         * object

         */

        public AccessibleRole getAccessibleRole() {

            return AccessibleRole.CHECK_BOX;

        }

    } // inner class AccessibleJCheckBoxMenuItem

}