/*

 * Copyright (c) 1997, 2013, 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.beans.ConstructorProperties;

import java.awt.*;

import java.awt.event.*;

import java.awt.image.*;

import javax.swing.plaf.*;

import javax.swing.event.*;

import javax.accessibility.*;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

/**

 * An implementation of a "push" button.

  * <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://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="http://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 information and examples of using buttons.

 * <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}.

 *

 * @beaninfo

 *   attribute: isContainer false

 * description: An implementation of a \"push\" button.

 *

 * @author Jeff Dinkins

 */

@SuppressWarnings("serial")

public class JButton extends AbstractButton implements Accessible {

    /**

     * @see #getUIClassID

     * @see #readObject

     */

    private static final String uiClassID = "ButtonUI";

    /**

     * Creates a button with no set text or icon.

     */

    public JButton() {

        this(null, null);

    }

    /**

     * Creates a button with an icon.

     *

     * @param icon  the Icon image to display on the button

     */

    public JButton(Icon icon) {

        this(null, icon);

    }

    /**

     * Creates a button with text.

     *

     * @param text  the text of the button

     */

    @ConstructorProperties({"text"})

    public JButton(String text) {

        this(text, null);

    }

    /**

     * Creates a button where properties are taken from the

     * <code>Action</code> supplied.

     *

     * @param a the <code>Action</code> used to specify the new button

     *

     * @since 1.3

     */

    public JButton(Action a) {

        this();

        setAction(a);

    }

    /**

     * Creates a button with initial text and an icon.

     *

     * @param text  the text of the button

     * @param icon  the Icon image to display on the button

     */

    public JButton(String text, Icon icon) {

        // Create the model

        setModel(new DefaultButtonModel());

        // initialize

        init(text, icon);

    }

    /**

     * 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 "ButtonUI"

     * @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;

    }

    /**

     * Gets the value of the <code>defaultButton</code> property,

     * which if <code>true</code> means that this button is the current

     * default button for its <code>JRootPane</code>.

     * Most look and feels render the default button

     * differently, and may potentially provide bindings

     * to access the default button.

     *

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

     * @see JRootPane#setDefaultButton

     * @see #isDefaultCapable

     * @beaninfo

     *  description: Whether or not this button is the default button

     */

    public boolean isDefaultButton() {

        JRootPane root = SwingUtilities.getRootPane(this);

        if (root != null) {

            return root.getDefaultButton() == this;

        }

        return false;

    }

    /**

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

     *

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

     * @see #setDefaultCapable

     * @see #isDefaultButton

     * @see JRootPane#setDefaultButton

     */

    public boolean isDefaultCapable() {

        return defaultCapable;

    }

    /**

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

     * which determines whether this button can be

     * made the default button for its root pane.

     * The default value of the <code>defaultCapable</code>

     * property is <code>true</code> unless otherwise

     * specified by the look and feel.

     *

     * @param defaultCapable <code>true</code> if this button will be

     *        capable of being the default button on the

     *        <code>RootPane</code>; otherwise <code>false</code>

     * @see #isDefaultCapable

     * @beaninfo

     *        bound: true

     *    attribute: visualUpdate true

     *  description: Whether or not this button can be the default button

     */

    public void setDefaultCapable(boolean defaultCapable) {

        boolean oldDefaultCapable = this.defaultCapable;

        this.defaultCapable = defaultCapable;

        firePropertyChange("defaultCapable", oldDefaultCapable, defaultCapable);

    }

    /**

     * Overrides <code>JComponent.removeNotify</code> to check if

     * this button is currently set as the default button on the

     * <code>RootPane</code>, and if so, sets the <code>RootPane</code>'s

     * default button to <code>null</code> to ensure the

     * <code>RootPane</code> doesn't hold onto an invalid button reference.

     */

    public void removeNotify() {

        JRootPane root = SwingUtilities.getRootPane(this);

        if (root != null && root.getDefaultButton() == this) {

            root.setDefaultButton(null);

        }

        super.removeNotify();

    }

    /**

     * 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 <code>JButton</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>JButton</code>

     */

    protected String paramString() {

        String defaultCapableString = (defaultCapable ? "true" : "false");

        return super.paramString() +

            ",defaultCapable=" + defaultCapableString;

    }

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

// Accessibility support

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

    /**

     * Gets the <code>AccessibleContext</code> associated with this

     * <code>JButton</code>. For <code>JButton</code>s,

     * the <code>AccessibleContext</code> takes the form of an

     * <code>AccessibleJButton</code>.

     * A new <code>AccessibleJButton</code> instance is created if necessary.

     *

     * @return an <code>AccessibleJButton</code> that serves as the

     *         <code>AccessibleContext</code> of this <code>JButton</code>

     * @beaninfo

     *       expert: true

     *  description: The AccessibleContext associated with this Button.

     */

    public AccessibleContext getAccessibleContext() {

        if (accessibleContext == null) {

            accessibleContext = new AccessibleJButton();

        }

        return accessibleContext;

    }

    /**

     * This class implements accessibility support for the

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

     * Java Accessibility API appropriate to 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")

    protected class AccessibleJButton extends AccessibleAbstractButton {

        /**

         * Get the role of this object.

         *

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

         * object

         * @see AccessibleRole

         */

        public AccessibleRole getAccessibleRole() {

            return AccessibleRole.PUSH_BUTTON;

        }

    } // inner class AccessibleJButton

}