https://openjdk.java.net/ 
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package javax.swing;

import java.beans.JavaBean;
import java.beans.BeanProperty;

import javax.swing.plaf.*;
import javax.accessibility.*;

import java.io.ObjectOutputStream;
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 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 add method to include the JRadioButton objects
in the group.)


Note: The ButtonGroup object is a logical grouping -- not a physical grouping. To create a button panel, you should still create a JPanel or similar container-object and add a Border to it to set it off from surrounding components. 



Buttons can be configured, and to some degree controlled, by
Actions.  Using an
Action with a button has many benefits beyond directly
configuring a button.  Refer to 
Swing Components Supporting Action for more
details, and you can find more information in How
to Use Actions, a section in The Java Tutorial.


See How to Use Buttons, Check Boxes, and Radio Buttons
in The Java Tutorial
for further documentation.


Warning: Swing is not thread safe. For more
information see Swing's Threading
Policy.


Warning:
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
has been added to the java.beans package. Please see XMLEncoder. 
Author:Jeff Dinkins
See Also:
Since:1.2
/**
 * 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="https://docs.oracle.com/javase/tutorial/uiswing/misc/action.html">How
 * to Use Actions</a>, a section in <em>The Java Tutorial</em>.
 * <p>
 * See <a href="https://docs.oracle.com/javase/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
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @see ButtonGroup
 * @see JCheckBox
 * @author Jeff Dinkins
 * @since 1.2
 */
@JavaBean(description = "A component which can display it's state as selected or deselected.")
@SwingContainer(false)
@SuppressWarnings("serial") // Same-version serialization only
public class JRadioButton extends JToggleButton implements Accessible {

    
See Also:
/**
     * @see #getUIClassID
     * @see #readObject
     */
    private static final String uiClassID = "RadioButtonUI";


    
Creates an initially unselected radio button
with no set text.

/**
     * 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.

Params:
  • icon –  the image that the button should display
/**
     * 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.

Params:
  • a – an Action
Since:1.3
/**
     * Creates a radiobutton where properties are taken from the
     * Action supplied.
     *
     * @param a an {@code Action}
     * @since 1.3
     */
    public JRadioButton(Action a) {
        this();
        setAction(a);
    }

    
Creates a radio button with the specified image
and selection state, but no text.

Params:
  • icon –  the image that the button should display
  • selected –  if true, the button is initially selected;
                 otherwise, the button is initially unselected
/**
     * 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.

Params:
  • text –  the string displayed on the radio button
/**
     * 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.

Params:
  • text –  the string displayed on the radio button
  • selected –  if true, the button is initially selected;
                 otherwise, the button is initially unselected
/**
     * 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.

Params:
  • text –  the string displayed on the radio button
  • icon –  the image that the button should display
/**
     * 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.

Params:
  • text –  the string displayed on the radio button
  • icon –  the image that the button should display
  • selected – if true, the button is initially selected otherwise, the button is initially unselected
/**
     * 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
     * @param selected if {@code true}, the button is initially selected
     *                 otherwise, the button is initially unselected
     */
    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 Also:
  • updateUI.updateUI
/**
     * 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.

See Also:
Returns:the string "RadioButtonUI"
/**
     * Returns the name of the L&amp;F class
     * that renders this component.
     *
     * @return the string "RadioButtonUI"
     * @see JComponent#getUIClassID
     * @see UIDefaults#getUI
     */
    @BeanProperty(bound = false, 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.

/**
     * 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.

/**
     * 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 null.

Returns: a string representation of this JRadioButton.
/**
     * 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.

Returns:an AccessibleJRadioButton that serves as the
        AccessibleContext of this JRadioButton
/**
     * 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
     */
    @BeanProperty(bound = false, 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
JRadioButton class.  It provides an implementation of the
Java Accessibility API appropriate to radio button
user-interface elements.


Warning:
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
has been added to the java.beans package. Please see XMLEncoder. 
/**
     * 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
     * has been added to the <code>java.beans</code> package.
     * Please see {@link java.beans.XMLEncoder}.
     */
    @SuppressWarnings("serial") // Same-version serialization only
    protected class AccessibleJRadioButton extends AccessibleJToggleButton {

        
Get the role of this object.

See Also:
Returns:an instance of AccessibleRole describing the role of the object
/**
         * 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
}