    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     * RadialLayout.java
    029     * -----------------
    030     * (C) Copyright 2003, 2004, by Bryan Scott (for Australian Antarctic Division).
    031     *
    032     * Original Author:  Bryan Scott (for Australian Antarctic Division);
    033     * Contributor(s):   David Gilbert (for Object Refinery Limited);
    034     *
    035     *
    036     * Changes:
    037     * --------
    038     * 30-Jun-2003 : Version 1 (BS);
    039     * 24-Jul-2003 : Completed missing Javadocs (DG);
    040     *
    041     */
    042
    043    package org.jfree.layout;
    044
    045    import java.awt.Checkbox;
    046    import java.awt.Component;
    047    import java.awt.Container;
    048    import java.awt.Dimension;
    049    import java.awt.Frame;
    050    import java.awt.Insets;
    051    import java.awt.LayoutManager;
    052    import java.awt.Panel;
    053    import java.io.Serializable;
    054
    055    /**
    056     * RadialLayout is a component layout manager.  Compents are laid out in a
    057     * circle. If only one component is contained in the layout it is positioned
    058     * centrally, otherwise components are evenly spaced around the centre with
    059     * the first component placed to the North.
    060     *<P>
    061     * This code was developed to display CTD rosette firing control
    062     *
    063     * WARNING: Not thoughly tested, use at own risk.
    064     *
    065     * @author Bryan Scott (for Australian Antarctic Division)
    066     */
    067
    068    public class RadialLayout implements LayoutManager, Serializable {
    069
    070        /** For serialization. */
    071        private static final long serialVersionUID = -7582156799248315534L;
    072
    073        /** The minimum width. */
    074        private int minWidth = 0;
    075
    076        /** The minimum height. */
    077        private int minHeight = 0;
    078
    079        /** The maximum component width. */
    080        private int maxCompWidth = 0;
    081
    082        /** The maximum component height. */
    083        private int maxCompHeight = 0;
    084
    085        /** The preferred width. */
    086        private int preferredWidth = 0;
    087
    088        /** The preferred height. */
    089        private int preferredHeight = 0;
    090
    091        /** Size unknown flag. */
    092        private boolean sizeUnknown = true;
    093
    094        /**
    095         * Constructs this layout manager with default properties.
    096         */
    097        public RadialLayout() {
    098            super();
    099        }
    100
    101        /**
    102         * Not used.
    103         *
    104         * @param comp  the component.
    105         */
    106        public void addLayoutComponent(final Component comp) {
    107            // not used
    108        }
    109
    110        /**
    111         * Not used.
    112         *
    113         * @param comp  the component.
    114         */
    115        public void removeLayoutComponent(final Component comp) {
    116            // not used
    117        }
    118
    119        /**
    120         * Not used.
    121         *
    122         * @param name  the component name.
    123         * @param comp  the component.
    124         */
    125        public void addLayoutComponent(final String name, final Component comp) {
    126            // not used
    127        }
    128
    129        /**
    130         * Not used.
    131         *
    132         * @param name  the component name.
    133         * @param comp  the component.
    134         */
    135        public void removeLayoutComponent(final String name, final Component comp) {
    136            // not used
    137        }
    138
    139        /**
    140         * Sets the sizes attribute of the RadialLayout object.
    141         *
    142         * @param  parent  the parent.
    143         *
    144         * @see LayoutManager
    145         */
    146        private void setSizes(final Container parent) {
    147            final int nComps = parent.getComponentCount();
    148            //Reset preferred/minimum width and height.
    149            this.preferredWidth = 0;
    150            this.preferredHeight = 0;
    151            this.minWidth = 0;
    152            this.minHeight = 0;
    153            for (int i = 0; i < nComps; i++) {
    154                final Component c = parent.getComponent(i);
    155                if (c.isVisible()) {
    156                    final Dimension d = c.getPreferredSize();
    157                    if (this.maxCompWidth < d.width) {
    158                        this.maxCompWidth = d.width;
    159                    }
    160                    if (this.maxCompHeight < d.height) {
    161                        this.maxCompHeight = d.height;
    162                    }
    163                    this.preferredWidth += d.width;
    164                    this.preferredHeight += d.height;
    165                }
    166            }
    167            this.preferredWidth  = this.preferredWidth / 2;
    168            this.preferredHeight = this.preferredHeight / 2;
    169            this.minWidth = this.preferredWidth;
    170            this.minHeight = this.preferredHeight;
    171        }
    172
    173        /**
    174         * Returns the preferred size.
    175         *
    176         * @param parent  the parent.
    177         *
    178         * @return The preferred size.
    179         * @see LayoutManager
    180         */
    181        public Dimension preferredLayoutSize(final Container parent) {
    182            final Dimension dim = new Dimension(0, 0);
    183            setSizes(parent);
    184
    185            //Always add the container's insets!
    186            final Insets insets = parent.getInsets();
    187            dim.width = this.preferredWidth + insets.left + insets.right;
    188            dim.height = this.preferredHeight + insets.top + insets.bottom;
    189
    190            this.sizeUnknown = false;
    191            return dim;
    192        }
    193
    194        /**
    195         * Returns the minimum size.
    196         *
    197         * @param parent  the parent.
    198         *
    199         * @return The minimum size.
    200         * @see LayoutManager
    201         */
    202        public Dimension minimumLayoutSize(final Container parent) {
    203            final Dimension dim = new Dimension(0, 0);
    204
    205            //Always add the container's insets!
    206            final Insets insets = parent.getInsets();
    207            dim.width = this.minWidth + insets.left + insets.right;
    208            dim.height = this.minHeight + insets.top + insets.bottom;
    209
    210            this.sizeUnknown = false;
    211            return dim;
    212        }
    213
    214       /**
    215        * This is called when the panel is first displayed, and every time its size
    216        * changes.
    217        * Note: You CAN'T assume preferredLayoutSize or minimumLayoutSize will be
    218        * called -- in the case of applets, at least, they probably won't be.
    219        *
    220        * @param  parent  the parent.
    221        * @see LayoutManager
    222        */
    223        public void layoutContainer(final Container parent) {
    224            final Insets insets = parent.getInsets();
    225            final int maxWidth = parent.getSize().width
    226                - (insets.left + insets.right);
    227            final int maxHeight = parent.getSize().height
    228                - (insets.top + insets.bottom);
    229            final int nComps = parent.getComponentCount();
    230            int x = 0;
    231            int y = 0;
    232
    233            // Go through the components' sizes, if neither preferredLayoutSize nor
    234            // minimumLayoutSize has been called.
    235            if (this.sizeUnknown) {
    236                setSizes(parent);
    237            }
    238
    239            if (nComps < 2) {
    240                final Component c = parent.getComponent(0);
    241                if (c.isVisible()) {
    242                    final Dimension d = c.getPreferredSize();
    243                    c.setBounds(x, y, d.width, d.height);
    244                }
    245            }
    246            else {
    247                double radialCurrent = Math.toRadians(90);
    248                final double radialIncrement = 2 * Math.PI / nComps;
    249                final int midX = maxWidth / 2;
    250                final int midY = maxHeight / 2;
    251                final int a = midX - this.maxCompWidth;
    252                final int b = midY - this.maxCompHeight;
    253                for (int i = 0; i < nComps; i++) {
    254                    final Component c = parent.getComponent(i);
    255                    if (c.isVisible()) {
    256                        final Dimension d = c.getPreferredSize();
    257                        x = (int) (midX
    258                                   - (a * Math.cos(radialCurrent))
    259                                   - (d.getWidth() / 2)
    260                                   + insets.left);
    261                        y = (int) (midY
    262                                   - (b * Math.sin(radialCurrent))
    263                                   - (d.getHeight() / 2)
    264                                   + insets.top);
    265
    266                        // Set the component's size and position.
    267                        c.setBounds(x, y, d.width, d.height);
    268                    }
    269                    radialCurrent += radialIncrement;
    270                }
    271            }
    272        }
    273
    274        /**
    275         * Returns the class name.
    276         *
    277         * @return The class name.
    278         */
    279        public String toString() {
    280            return getClass().getName();
    281        }
    282
    283        /**
    284         * Run a demonstration.
    285         *
    286         * @param args  ignored.
    287         *
    288         * @throws Exception when an error occurs.
    289         */
    290        public static void main(final String[] args) throws Exception {
    291            final Frame frame = new Frame();
    292            final Panel panel = new Panel();
    293            panel.setLayout(new RadialLayout());
    294
    295            panel.add(new Checkbox("One"));
    296            panel.add(new Checkbox("Two"));
    297            panel.add(new Checkbox("Three"));
    298            panel.add(new Checkbox("Four"));
    299            panel.add(new Checkbox("Five"));
    300            panel.add(new Checkbox("One"));
    301            panel.add(new Checkbox("Two"));
    302            panel.add(new Checkbox("Three"));
    303            panel.add(new Checkbox("Four"));
    304            panel.add(new Checkbox("Five"));
    305
    306            frame.add(panel);
    307            frame.setSize(300, 500);
    308            frame.setVisible(true);
    309        }
    310
    311    }