/*

 * Copyright (c) 2003, 2005, 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.plaf.metal;

import java.awt.*;

import javax.swing.*;

import javax.swing.plaf.ComponentUI;

import javax.swing.plaf.UIResource;

import javax.swing.plaf.basic.*;

/**

 * Metal implementation of <code>MenuBarUI</code>. This class is responsible

 * for providing the metal look and feel for <code>JMenuBar</code>s.

 *

 * @see javax.swing.plaf.MenuBarUI

 * @since 1.5

 */

public class MetalMenuBarUI extends BasicMenuBarUI  {

    /**

     * Creates the <code>ComponentUI</code> implementation for the passed

     * in component.

     *

     * @param x JComponent to create the ComponentUI implementation for

     * @return ComponentUI implementation for <code>x</code>

     * @throws NullPointerException if <code>x</code> is null

     */

    public static ComponentUI createUI(JComponent x) {

        if (x == null) {

            throw new NullPointerException("Must pass in a non-null component");

        }

        return new MetalMenuBarUI();

    }

    /**

     * Configures the specified component appropriate for the metal look and

     * feel.

     *

     * @param c the component where this UI delegate is being installed

     * @throws NullPointerException if <code>c</code> is null.

     */

    public void installUI(JComponent c) {

        super.installUI(c);

        MetalToolBarUI.register(c);

    }

    /**

     * Reverses configuration which was done on the specified component during

     * <code>installUI</code>.

     *

     * @param c the component where this UI delegate is being installed

     * @throws NullPointerException if <code>c</code> is null.

     */

    public void uninstallUI(JComponent c) {

        super.uninstallUI(c);

        MetalToolBarUI.unregister(c);

    }

    /**

     * If necessary paints the background of the component, then

     * invokes <code>paint</code>.

     *

     * @param g Graphics to paint to

     * @param c JComponent painting on

     * @throws NullPointerException if <code>g</code> or <code>c</code> is

     *         null

     * @see javax.swing.plaf.ComponentUI#update

     * @see javax.swing.plaf.ComponentUI#paint

     * @since 1.5

     */

    public void update(Graphics g, JComponent c) {

        boolean isOpaque = c.isOpaque();

        if (g == null) {

            throw new NullPointerException("Graphics must be non-null");

        }

        if (isOpaque && (c.getBackground() instanceof UIResource) &&

                        UIManager.get("MenuBar.gradient") != null) {

            if (MetalToolBarUI.doesMenuBarBorderToolBar((JMenuBar)c)) {

                JToolBar tb = (JToolBar)MetalToolBarUI.

                     findRegisteredComponentOfType(c, JToolBar.class);

                if (tb.isOpaque() &&tb.getBackground() instanceof UIResource) {

                    MetalUtils.drawGradient(c, g, "MenuBar.gradient", 0, 0,

                                            c.getWidth(), c.getHeight() +

                                            tb.getHeight(), true);

                    paint(g, c);

                    return;

                }

            }

            MetalUtils.drawGradient(c, g, "MenuBar.gradient", 0, 0,

                                    c.getWidth(), c.getHeight(),true);

            paint(g, c);

        }

        else {

            super.update(g, c);

        }

    }

}