1/*
2 * Copyright (c) 1998, 2014, 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.basic;
27
28
29import java.awt.*;
30import java.io.*;
31
32/**
33  * Center-positioning layout manager.
34  * @author Tom Santos
35  * @author Steve Wilson
36  */
37@SuppressWarnings("serial") // Same-version serialization only
38class CenterLayout implements LayoutManager, Serializable {
39    public void addLayoutComponent(String name, Component comp) { }
40    public void removeLayoutComponent(Component comp) { }
41
42    public Dimension preferredLayoutSize( Container container ) {
43        Component c = container.getComponent( 0 );
44        if ( c != null ) {
45            Dimension size = c.getPreferredSize();
46            Insets insets = container.getInsets();
47
48            return new Dimension(size.width + insets.left + insets.right,
49                                 size.height + insets.top + insets.bottom);
50        }
51        else {
52            return new Dimension( 0, 0 );
53        }
54    }
55
56    public Dimension minimumLayoutSize(Container cont) {
57        return preferredLayoutSize(cont);
58    }
59
60    public void layoutContainer(Container container) {
61        if (container.getComponentCount() > 0) {
62            Component c = container.getComponent(0);
63            Dimension pref = c.getPreferredSize();
64            int containerWidth = container.getWidth();
65            int containerHeight = container.getHeight();
66            Insets containerInsets = container.getInsets();
67
68            containerWidth -= containerInsets.left +
69                              containerInsets.right;
70            containerHeight -= containerInsets.top +
71                               containerInsets.bottom;
72
73            int left = (containerWidth - pref.width) / 2 +
74                            containerInsets.left;
75            int right = (containerHeight - pref.height) / 2 +
76                            containerInsets.top;
77
78            c.setBounds(left, right, pref.width, pref.height);
79        }
80    }
81}
82