/*

 * 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.*;

/**

 * An implementation of a radio button menu item.

 * A <code>JRadioButtonMenuItem</code> is

 * a menu item that is part of a group of menu items in which only one

 * item in the group can be selected. The selected item displays its

 * selected state. Selecting it causes any other selected item to

 * switch to the unselected state.

 * To control the selected state of a group of radio button menu items,

 * use a <code>ButtonGroup</code> object.

 * <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 documentation and examples 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 component within a group of menu items which can be selected.

 *

 * @author Georges Saab

 * @author David Karlton

 * @see ButtonGroup

 */

public class JRadioButtonMenuItem extends JMenuItem implements Accessible {

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "RadioButtonMenuItemUI";

    /**

     * Creates a <code>JRadioButtonMenuItem</code> with no set text or icon.

     */

    public JRadioButtonMenuItem() {

        this(null, null, false);

    }

    /**

     * Creates a <code>JRadioButtonMenuItem</code> with an icon.

     *

     * @param icon the <code>Icon</code> to display on the

     *          <code>JRadioButtonMenuItem</code>

     */

    public JRadioButtonMenuItem(Icon icon) {

        this(null, icon, false);

    }

    /**

     * Creates a <code>JRadioButtonMenuItem</code> with text.

     *

     * @param text the text of the <code>JRadioButtonMenuItem</code>

     */

    public JRadioButtonMenuItem(String text) {

        this(text, null, false);

    }

    /**

     * Creates a radio button menu item whose properties are taken from the

     * <code>Action</code> supplied.

     *

     * @param  a the <code>Action</code> on which to base the radio

     *          button menu item

     *

     * @since 1.3

     */

    public JRadioButtonMenuItem(Action a) {

        this();

        setAction(a);

    }

    /**

     * Creates a radio button menu item with the specified text

     * and <code>Icon</code>.

     *

     * @param text the text of the <code>JRadioButtonMenuItem</code>

     * @param icon the icon to display on the <code>JRadioButtonMenuItem</code>

     */

    public JRadioButtonMenuItem(String text, Icon icon) {

        this(text, icon, false);

    }

    /**

     * Creates a radio button menu item with the specified text

     * and selection state.

     *

     * @param text the text of the <code>CheckBoxMenuItem</code>

     * @param selected the selected state of the <code>CheckBoxMenuItem</code>

     */

    public JRadioButtonMenuItem(String text, boolean selected) {

        this(text);

        setSelected(selected);

    }

    /**

     * Creates a radio button menu item with the specified image

     * and selection state, but no text.

     *

     * @param icon  the image that the button should display

     * @param selected  if true, the button is initially selected;

     *                  otherwise, the button is initially unselected

     */

    public JRadioButtonMenuItem(Icon icon, boolean selected) {

        this(null, icon, selected);

    }

    /**

     * Creates a radio button menu item that has the specified

     * text, image, and selection state.  All other constructors

     * defer to this one.

     *

     * @param text  the string displayed on the radio button

     * @param icon  the image that the button should display

     */

    public JRadioButtonMenuItem(String text, Icon icon, boolean selected) {

        super(text, icon);

        setModel(new JToggleButton.ToggleButtonModel());

        setSelected(selected);

        setFocusable(false);

    }

    /**

     * Returns the name of the L&F class that renders this component.

     *

     * @return the string "RadioButtonMenuItemUI"

     * @see JComponent#getUIClassID

     * @see UIDefaults#getUI

     */

    public String getUIClassID() {

        return uiClassID;

    }

    /**

     * See <code>readObject</code> and <code>writeObject</code> in

     * <code>JComponent</code> 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

     * <code>JRadioButtonMenuItem</code>.  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

     *          <code>JRadioButtonMenuItem</code>

     */

    protected String paramString() {

        return super.paramString();

    }

    /**

     * Overriden to return true, JRadioButtonMenuItem supports

     * the selected state.

     */

    boolean shouldUpdateSelectedStateFromAction() {

        return true;

    }

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

// Accessibility support

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

    /**

     * Gets the AccessibleContext associated with this JRadioButtonMenuItem.

     * For JRadioButtonMenuItems, the AccessibleContext takes the form of an

     * AccessibleJRadioButtonMenuItem.

     * A new AccessibleJRadioButtonMenuItem instance is created if necessary.

     *

     * @return an AccessibleJRadioButtonMenuItem that serves as the

     *         AccessibleContext of this JRadioButtonMenuItem

     */

    public AccessibleContext getAccessibleContext() {

        if (accessibleContext == null) {

            accessibleContext = new AccessibleJRadioButtonMenuItem();

        }

        return accessibleContext;

    }

    /**

     * This class implements accessibility support for the

     * <code>JRadioButtonMenuItem</code> class.  It provides an

     * implementation of the Java Accessibility API appropriate to

     * <code>JRadioButtonMenuItem</code> 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 AccessibleJRadioButtonMenuItem extends AccessibleJMenuItem {

        /**

         * Get the role of this object.

         *

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

         * object

         */

        public AccessibleRole getAccessibleRole() {

            return AccessibleRole.RADIO_BUTTON;

        }

    } // inner class AccessibleJRadioButtonMenuItem

}