    001    /* ========================================================================
    002     * JCommon : a free general purpose class library for the Java(tm) platform
    003     * ========================================================================
    004     *
    005     * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
    006     *
    007     * Project Info:  http://www.jfree.org/jcommon/index.html
    008     *
    009     * This library is free software; you can redistribute it and/or modify it
    010     * under the terms of the GNU Lesser General Public License as published by
    011     * the Free Software Foundation; either version 2.1 of the License, or
    012     * (at your option) any later version.
    013     *
    014     * This library is distributed in the hope that it will be useful, but
    015     * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
    016     * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
    017     * License for more details.
    018     *
    019     * You should have received a copy of the GNU Lesser General Public
    020     * License along with this library; if not, write to the Free Software
    021     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
    022     * USA.
    023     *
    024     * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
    025     * in the United States and other countries.]
    026     *
    027     * -----------------
    028     * CenterLayout.java
    029     * -----------------
    030     * (C) Copyright 2000-2005, by Object Refinery Limited.
    031     *
    032     * Original Author:  David Gilbert (for Object Refinery Limited);
    033     * Contributor(s):   -;
    034     *
    035     * $Id: CenterLayout.java,v 1.6 2005/11/16 15:58:40 taqua Exp $
    036     *
    037     * Changes (from 5-Nov-2001)
    038     * -------------------------
    039     * 05-Nov-2001 : Changed package to com.jrefinery.layout.* (DG);
    040     * 10-Oct-2002 : Fixed errors reported by Checkstyle (DG);
    041     *
    042     */
    043
    044    package org.jfree.layout;
    045
    046    import java.awt.Component;
    047    import java.awt.Container;
    048    import java.awt.Dimension;
    049    import java.awt.Insets;
    050    import java.awt.LayoutManager;
    051    import java.io.Serializable;
    052
    053    /**
    054     * A layout manager that displays a single component in the center of its
    055     * container.
    056     *
    057     * @author David Gilbert
    058     */
    059    public class CenterLayout implements LayoutManager, Serializable {
    060
    061        /** For serialization. */
    062        private static final long serialVersionUID = 469319532333015042L;
    063
    064        /**
    065         * Creates a new layout manager.
    066         */
    067        public CenterLayout() {
    068        }
    069
    070        /**
    071         * Returns the preferred size.
    072         *
    073         * @param parent  the parent.
    074         *
    075         * @return the preferred size.
    076         */
    077        public Dimension preferredLayoutSize(final Container parent) {
    078
    079            synchronized (parent.getTreeLock()) {
    080                final Insets insets = parent.getInsets();
    081                if (parent.getComponentCount() > 0) {
    082                    final Component component = parent.getComponent(0);
    083                    final Dimension d = component.getPreferredSize();
    084                    return new Dimension(
    085                        (int) d.getWidth() + insets.left + insets.right,
    086                        (int) d.getHeight() + insets.top + insets.bottom
    087                    );
    088                }
    089                else {
    090                    return new Dimension(
    091                        insets.left + insets.right, insets.top + insets.bottom
    092                    );
    093                }
    094            }
    095
    096        }
    097
    098        /**
    099         * Returns the minimum size.
    100         *
    101         * @param parent  the parent.
    102         *
    103         * @return the minimum size.
    104         */
    105        public Dimension minimumLayoutSize(final Container parent) {
    106
    107            synchronized (parent.getTreeLock()) {
    108                final Insets insets = parent.getInsets();
    109                if (parent.getComponentCount() > 0) {
    110                    final Component component = parent.getComponent(0);
    111                    final Dimension d = component.getMinimumSize();
    112                    return new Dimension(d.width + insets.left + insets.right,
    113                                     d.height + insets.top + insets.bottom);
    114                }
    115                else {
    116                  return new Dimension(insets.left + insets.right,
    117                                       insets.top + insets.bottom);
    118                }
    119            }
    120
    121        }
    122
    123        /**
    124         * Lays out the components.
    125         *
    126         * @param parent  the parent.
    127         */
    128        public void layoutContainer(final Container parent) {
    129
    130            synchronized (parent.getTreeLock()) {
    131                if (parent.getComponentCount() > 0) {
    132                    final Insets insets = parent.getInsets();
    133                    final Dimension parentSize = parent.getSize();
    134                    final Component component = parent.getComponent(0);
    135                    final Dimension componentSize = component.getPreferredSize();
    136                    final int xx = insets.left + (
    137                        Math.max((parentSize.width - insets.left - insets.right
    138                                          - componentSize.width) / 2, 0)
    139                    );
    140                    final int yy = insets.top + (
    141                        Math.max((parentSize.height - insets.top - insets.bottom
    142                                          - componentSize.height) / 2, 0));
    143                    component.setBounds(xx, yy, componentSize.width,
    144                            componentSize.height);
    145                }
    146            }
    147
    148        }
    149
    150        /**
    151         * Not used.
    152         *
    153         * @param comp  the component.
    154         */
    155        public void addLayoutComponent(final Component comp) {
    156            // not used.
    157        }
    158
    159        /**
    160         * Not used.
    161         *
    162         * @param comp  the component.
    163         */
    164        public void removeLayoutComponent(final Component comp) {
    165            // not used
    166        }
    167
    168        /**
    169         * Not used.
    170         *
    171         * @param name  the component name.
    172         * @param comp  the component.
    173         */
    174        public void addLayoutComponent(final String name, final Component comp) {
    175            // not used
    176        }
    177
    178        /**
    179         * Not used.
    180         *
    181         * @param name  the component name.
    182         * @param comp  the component.
    183         */
    184        public void removeLayoutComponent(final String name, final Component comp) {
    185            // not used
    186        }
    187
    188    }