/*

 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. 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.  Oracle designates this

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

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.swing;

import java.awt.*;

import java.awt.event.*;

import java.beans.*;

import javax.swing.plaf.*;

import javax.accessibility.*;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

/**

 * An implementation of a radio button -- an item that can be selected or

 * deselected, and which displays its state to the user.

 * Used with a {@link ButtonGroup} object to create a group of buttons

 * in which only one button at a time can be selected. (Create a ButtonGroup

 * object and use its <code>add</code> method to include the JRadioButton objects

 * in the group.)

 * <blockquote>

 * <strong>Note:</strong>

 * The ButtonGroup object is a logical grouping -- not a physical grouping.

 * To create a button panel, you should still create a {@link JPanel} or similar

 * container-object and add a {@link javax.swing.border.Border} to it to set it off from surrounding

 * components.

 * </blockquote>

 * <p>

 * Buttons 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 button has many benefits beyond directly

 * configuring a button.  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>

 * See <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/button.html">How to Use Buttons, Check Boxes, and Radio Buttons</a>

 * in <em>The Java Tutorial</em>

 * for further documentation.

 * <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 which can display it's state as selected or deselected.

 *

 * @see ButtonGroup

 * @see JCheckBox

 * @author Jeff Dinkins

 */

public class JRadioButton extends JToggleButton implements Accessible {

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "RadioButtonUI";

    /**

     * Creates an initially unselected radio button

     * with no set text.

     */

    public JRadioButton () {

        this(null, null, false);

    }

    /**

     * Creates an initially unselected radio button

     * with the specified image but no text.

     *

     * @param icon  the image that the button should display

     */

    public JRadioButton(Icon icon) {

        this(null, icon, false);

    }

    /**

     * Creates a radiobutton where properties are taken from the

     * Action supplied.

     *

     * @since 1.3

     */

    public JRadioButton(Action a) {

        this();

        setAction(a);

    }

    /**

     * Creates a radio button 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 JRadioButton(Icon icon, boolean selected) {

        this(null, icon, selected);

    }

    /**

     * Creates an unselected radio button with the specified text.

     *

     * @param text  the string displayed on the radio button

     */

    public JRadioButton (String text) {

        this(text, null, false);

    }

    /**

     * Creates a radio button with the specified text

     * and selection state.

     *

     * @param text  the string displayed on the radio button

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

     *                  otherwise, the button is initially unselected

     */

    public JRadioButton (String text, boolean selected) {

        this(text, null, selected);

    }

    /**

     * Creates a radio button that has the specified text and image,

     * and that is initially unselected.

     *

     * @param text  the string displayed on the radio button

     * @param icon  the image that the button should display

     */

    public JRadioButton(String text, Icon icon) {

        this(text, icon, false);

    }

    /**

     * Creates a radio button that has the specified text, image,

     * and selection state.

     *

     * @param text  the string displayed on the radio button

     * @param icon  the image that the button should display

     */

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

        super(text, icon, selected);

        setBorderPainted(false);

        setHorizontalAlignment(LEADING);

    }

    /**

     * Resets the UI property to a value from the current look and feel.

     *

     * @see JComponent#updateUI

     */

    public void updateUI() {

        setUI((ButtonUI)UIManager.getUI(this));

    }

    /**

     * Returns the name of the L&F class

     * that renders this component.

     *

     * @return String "RadioButtonUI"

     * @see JComponent#getUIClassID

     * @see UIDefaults#getUI

     * @beaninfo

     *        expert: true

     *   description: A string that specifies the name of the L&F class.

     */

    public String getUIClassID() {

        return uiClassID;

    }

    /**

     * The icon for radio buttons comes from the look and feel,

     * not the Action.

     */

    void setIconFromAction(Action a) {

    }

    /**

     * 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 JRadioButton. 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 JRadioButton.

     */

    protected String paramString() {

        return super.paramString();

    }

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

// Accessibility support

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

    /**

     * Gets the AccessibleContext associated with this JRadioButton.

     * For JRadioButtons, the AccessibleContext takes the form of an

     * AccessibleJRadioButton.

     * A new AccessibleJRadioButton instance is created if necessary.

     *

     * @return an AccessibleJRadioButton that serves as the

     *         AccessibleContext of this JRadioButton

     * @beaninfo

     *       expert: true

     *  description: The AccessibleContext associated with this Button

     */

    public AccessibleContext getAccessibleContext() {

        if (accessibleContext == null) {

            accessibleContext = new AccessibleJRadioButton();

        }

        return accessibleContext;

    }

    /**

     * This class implements accessibility support for the

     * <code>JRadioButton</code> class.  It provides an implementation of the

     * Java Accessibility API appropriate to radio button

     * 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 AccessibleJRadioButton extends AccessibleJToggleButton {

        /**

         * Get the role of this object.

         *

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

         * @see AccessibleRole

         */

        public AccessibleRole getAccessibleRole() {

            return AccessibleRole.RADIO_BUTTON;

        }

    } // inner class AccessibleJRadioButton

}