/*
* 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
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*/
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
}