/*

 * 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.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 check box -- an item that can be selected or

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

 * By convention, any number of check boxes in a group can be selected.

 * 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 examples and information on using check boxes.

 * <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>

 * <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}.

 *

 * @see JRadioButton

 *

 * @beaninfo

 *   attribute: isContainer false

 * description: A component which can be selected or deselected.

 *

 * @author Jeff Dinkins

 */

public class JCheckBox extends JToggleButton implements Accessible {

    /** Identifies a change to the flat property. */

    public static final String BORDER_PAINTED_FLAT_CHANGED_PROPERTY = "borderPaintedFlat";

    private boolean flat = false;

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "CheckBoxUI";

    /**

     * Creates an initially unselected check box button with no text, no icon.

     */

    public JCheckBox () {

        this(null, null, false);

    }

    /**

     * Creates an initially unselected check box with an icon.

     *

     * @param icon  the Icon image to display

     */

    public JCheckBox(Icon icon) {

        this(null, icon, false);

    }

    /**

     * Creates a check box with an icon and specifies whether

     * or not it is initially selected.

     *

     * @param icon  the Icon image to display

     * @param selected a boolean value indicating the initial selection

     *        state. If <code>true</code> the check box is selected

     */

    public JCheckBox(Icon icon, boolean selected) {

        this(null, icon, selected);

    }

    /**

     * Creates an initially unselected check box with text.

     *

     * @param text the text of the check box.

     */

    public JCheckBox (String text) {

        this(text, null, false);

    }

    /**

     * Creates a check box where properties are taken from the

     * Action supplied.

     *

     * @since 1.3

     */

    public JCheckBox(Action a) {

        this();

        setAction(a);

    }

    /**

     * Creates a check box with text and specifies whether

     * or not it is initially selected.

     *

     * @param text the text of the check box.

     * @param selected a boolean value indicating the initial selection

     *        state. If <code>true</code> the check box is selected

     */

    public JCheckBox (String text, boolean selected) {

        this(text, null, selected);

    }

    /**

     * Creates an initially unselected check box with

     * the specified text and icon.

     *

     * @param text the text of the check box.

     * @param icon  the Icon image to display

     */

    public JCheckBox(String text, Icon icon) {

        this(text, icon, false);

    }

    /**

     * Creates a check box with text and icon,

     * and specifies whether or not it is initially selected.

     *

     * @param text the text of the check box.

     * @param icon  the Icon image to display

     * @param selected a boolean value indicating the initial selection

     *        state. If <code>true</code> the check box is selected

     */

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

        super(text, icon, selected);

        setUIProperty("borderPainted", Boolean.FALSE);

        setHorizontalAlignment(LEADING);

    }

    /**

     * Sets the <code>borderPaintedFlat</code> property,

     * which gives a hint to the look and feel as to the

     * appearance of the check box border.

     * This is usually set to <code>true</code> when a

     * <code>JCheckBox</code> instance is used as a

     * renderer in a component such as a <code>JTable</code> or

     * <code>JTree</code>.  The default value for the

     * <code>borderPaintedFlat</code> property is <code>false</code>.

     * This method fires a property changed event.

     * Some look and feels might not implement flat borders;

     * they will ignore this property.

     *

     * @param b <code>true</code> requests that the border be painted flat;

     *          <code>false</code> requests normal borders

     * @see #isBorderPaintedFlat

     * @beaninfo

     *        bound: true

     *    attribute: visualUpdate true

     *  description: Whether the border is painted flat.

     * @since 1.3

     */

    public void setBorderPaintedFlat(boolean b) {

        boolean oldValue = flat;

        flat = b;

        firePropertyChange(BORDER_PAINTED_FLAT_CHANGED_PROPERTY, oldValue, flat);

        if (b != oldValue) {

            revalidate();

            repaint();

        }

    }

    /**

     * Gets the value of the <code>borderPaintedFlat</code> property.

     *

     * @return the value of the <code>borderPaintedFlat</code> property

     * @see #setBorderPaintedFlat

     * @since 1.3

     */

    public boolean isBorderPaintedFlat() {

        return flat;

    }

    /**

     * 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 a string that specifies the name of the L&F class

     * that renders this component.

     *

     * @return the string "CheckBoxUI"

     * @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 checkboxs comes from the look and feel,

     * not the Action; this is overriden to do nothing.

     */

    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);

            }

        }

     }

    /**

     * See JComponent.readObject() for information about serialization

     * in Swing.

     */

    private void readObject(ObjectInputStream s)

        throws IOException, ClassNotFoundException

    {

        s.defaultReadObject();

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

            updateUI();

        }

    }

    /**

     * Returns a string representation of this JCheckBox. 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>.

     * specific new aspects of the JFC components.

     *

     * @return  a string representation of this JCheckBox.

     */

    protected String paramString() {

        return super.paramString();

    }

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

// Accessibility support

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

    /**

     * Gets the AccessibleContext associated with this JCheckBox.

     * For JCheckBoxes, the AccessibleContext takes the form of an

     * AccessibleJCheckBox.

     * A new AccessibleJCheckBox instance is created if necessary.

     *

     * @return an AccessibleJCheckBox that serves as the

     *         AccessibleContext of this JCheckBox

     * @beaninfo

     *       expert: true

     *  description: The AccessibleContext associated with this CheckBox.

     */

    public AccessibleContext getAccessibleContext() {

        if (accessibleContext == null) {

            accessibleContext = new AccessibleJCheckBox();

        }

        return accessibleContext;

    }

    /**

     * This class implements accessibility support for the

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

     * Java Accessibility API appropriate to check box 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 AccessibleJCheckBox 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.CHECK_BOX;

        }

    } // inner class AccessibleJCheckBox

}