1/*
2 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package javax.swing.plaf.metal;
27
28import java.awt.*;
29import javax.swing.*;
30import javax.swing.plaf.ComponentUI;
31import javax.swing.plaf.UIResource;
32import javax.swing.plaf.basic.*;
33
34/**
35 * Metal implementation of <code>MenuBarUI</code>. This class is responsible
36 * for providing the metal look and feel for <code>JMenuBar</code>s.
37 *
38 * @see javax.swing.plaf.MenuBarUI
39 * @since 1.5
40 */
41public class MetalMenuBarUI extends BasicMenuBarUI  {
42    /**
43     * Creates the <code>ComponentUI</code> implementation for the passed
44     * in component.
45     *
46     * @param x JComponent to create the ComponentUI implementation for
47     * @return ComponentUI implementation for <code>x</code>
48     * @throws NullPointerException if <code>x</code> is null
49     */
50    public static ComponentUI createUI(JComponent x) {
51        if (x == null) {
52            throw new NullPointerException("Must pass in a non-null component");
53        }
54        return new MetalMenuBarUI();
55    }
56
57    /**
58     * Configures the specified component appropriate for the metal look and
59     * feel.
60     *
61     * @param c the component where this UI delegate is being installed
62     * @throws NullPointerException if <code>c</code> is null.
63     */
64    public void installUI(JComponent c) {
65        super.installUI(c);
66        MetalToolBarUI.register(c);
67    }
68
69    /**
70     * Reverses configuration which was done on the specified component during
71     * <code>installUI</code>.
72     *
73     * @param c the component where this UI delegate is being installed
74     * @throws NullPointerException if <code>c</code> is null.
75     */
76    public void uninstallUI(JComponent c) {
77        super.uninstallUI(c);
78        MetalToolBarUI.unregister(c);
79    }
80
81    /**
82     * If necessary paints the background of the component, then
83     * invokes <code>paint</code>.
84     *
85     * @param g Graphics to paint to
86     * @param c JComponent painting on
87     * @throws NullPointerException if <code>g</code> or <code>c</code> is
88     *         null
89     * @see javax.swing.plaf.ComponentUI#update
90     * @see javax.swing.plaf.ComponentUI#paint
91     * @since 1.5
92     */
93    public void update(Graphics g, JComponent c) {
94        boolean isOpaque = c.isOpaque();
95        if (g == null) {
96            throw new NullPointerException("Graphics must be non-null");
97        }
98        if (isOpaque && (c.getBackground() instanceof UIResource) &&
99                        UIManager.get("MenuBar.gradient") != null) {
100            if (MetalToolBarUI.doesMenuBarBorderToolBar((JMenuBar)c)) {
101                JToolBar tb = (JToolBar)MetalToolBarUI.
102                     findRegisteredComponentOfType(c, JToolBar.class);
103                if (tb.isOpaque() &&tb.getBackground() instanceof UIResource) {
104                    MetalUtils.drawGradient(c, g, "MenuBar.gradient", 0, 0,
105                                            c.getWidth(), c.getHeight() +
106                                            tb.getHeight(), true);
107                    paint(g, c);
108                    return;
109                }
110            }
111            MetalUtils.drawGradient(c, g, "MenuBar.gradient", 0, 0,
112                                    c.getWidth(), c.getHeight(),true);
113            paint(g, c);
114        }
115        else {
116            super.update(g, c);
117        }
118    }
119}
120