Java tutorial
/* * JCommon : a free general purpose class library for the Java(tm) platform * * * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jcommon/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library 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 Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Java is a trademark or registered trademark of Sun Microsystems, Inc. * in the United States and other countries.] * * ----------------- * RadialLayout.java * ----------------- * (C) Copyright 2003, 2004, by Bryan Scott (for Australian Antarctic Division). * * Original Author: Bryan Scott (for Australian Antarctic Division); * Contributor(s): David Gilbert (for Object Refinery Limited); * * * Changes: * -------- * 30-Jun-2003 : Version 1 (BS); * 24-Jul-2003 : Completed missing Javadocs (DG); * */ import java.awt.Checkbox; import java.awt.Component; import java.awt.Container; import java.awt.Dimension; import java.awt.Frame; import java.awt.Insets; import java.awt.LayoutManager; import java.awt.Panel; import java.io.Serializable; /** * RadialLayout is a component layout manager. Compents are laid out in a * circle. If only one component is contained in the layout it is positioned * centrally, otherwise components are evenly spaced around the centre with * the first component placed to the North. *<P> * This code was developed to display CTD rosette firing control * * WARNING: Not thoughly tested, use at own risk. * * @author Bryan Scott (for Australian Antarctic Division) */ public class RadialLayout implements LayoutManager, Serializable { /** For serialization. */ private static final long serialVersionUID = -7582156799248315534L; /** The minimum width. */ private int minWidth = 0; /** The minimum height. */ private int minHeight = 0; /** The maximum component width. */ private int maxCompWidth = 0; /** The maximum component height. */ private int maxCompHeight = 0; /** The preferred width. */ private int preferredWidth = 0; /** The preferred height. */ private int preferredHeight = 0; /** Size unknown flag. */ private boolean sizeUnknown = true; /** * Constructs this layout manager with default properties. */ public RadialLayout() { super(); } /** * Not used. * * @param comp the component. */ public void addLayoutComponent(final Component comp) { // not used } /** * Not used. * * @param comp the component. */ public void removeLayoutComponent(final Component comp) { // not used } /** * Not used. * * @param name the component name. * @param comp the component. */ public void addLayoutComponent(final String name, final Component comp) { // not used } /** * Not used. * * @param name the component name. * @param comp the component. */ public void removeLayoutComponent(final String name, final Component comp) { // not used } /** * Sets the sizes attribute of the RadialLayout object. * * @param parent the parent. * * @see LayoutManager */ private void setSizes(final Container parent) { final int nComps = parent.getComponentCount(); //Reset preferred/minimum width and height. this.preferredWidth = 0; this.preferredHeight = 0; this.minWidth = 0; this.minHeight = 0; for (int i = 0; i < nComps; i++) { final Component c = parent.getComponent(i); if (c.isVisible()) { final Dimension d = c.getPreferredSize(); if (this.maxCompWidth < d.width) { this.maxCompWidth = d.width; } if (this.maxCompHeight < d.height) { this.maxCompHeight = d.height; } this.preferredWidth += d.width; this.preferredHeight += d.height; } } this.preferredWidth = this.preferredWidth / 2; this.preferredHeight = this.preferredHeight / 2; this.minWidth = this.preferredWidth; this.minHeight = this.preferredHeight; } /** * Returns the preferred size. * * @param parent the parent. * * @return The preferred size. * @see LayoutManager */ public Dimension preferredLayoutSize(final Container parent) { final Dimension dim = new Dimension(0, 0); setSizes(parent); //Always add the container's insets! final Insets insets = parent.getInsets(); dim.width = this.preferredWidth + insets.left + insets.right; dim.height = this.preferredHeight + insets.top + insets.bottom; this.sizeUnknown = false; return dim; } /** * Returns the minimum size. * * @param parent the parent. * * @return The minimum size. * @see LayoutManager */ public Dimension minimumLayoutSize(final Container parent) { final Dimension dim = new Dimension(0, 0); //Always add the container's insets! final Insets insets = parent.getInsets(); dim.width = this.minWidth + insets.left + insets.right; dim.height = this.minHeight + insets.top + insets.bottom; this.sizeUnknown = false; return dim; } /** * This is called when the panel is first displayed, and every time its size * changes. * Note: You CAN'T assume preferredLayoutSize or minimumLayoutSize will be * called -- in the case of applets, at least, they probably won't be. * * @param parent the parent. * @see LayoutManager */ public void layoutContainer(final Container parent) { final Insets insets = parent.getInsets(); final int maxWidth = parent.getSize().width - (insets.left + insets.right); final int maxHeight = parent.getSize().height - (insets.top + insets.bottom); final int nComps = parent.getComponentCount(); int x = 0; int y = 0; // Go through the components' sizes, if neither preferredLayoutSize nor // minimumLayoutSize has been called. if (this.sizeUnknown) { setSizes(parent); } if (nComps < 2) { final Component c = parent.getComponent(0); if (c.isVisible()) { final Dimension d = c.getPreferredSize(); c.setBounds(x, y, d.width, d.height); } } else { double radialCurrent = Math.toRadians(90); final double radialIncrement = 2 * Math.PI / nComps; final int midX = maxWidth / 2; final int midY = maxHeight / 2; final int a = midX - this.maxCompWidth; final int b = midY - this.maxCompHeight; for (int i = 0; i < nComps; i++) { final Component c = parent.getComponent(i); if (c.isVisible()) { final Dimension d = c.getPreferredSize(); x = (int) (midX - (a * Math.cos(radialCurrent)) - (d.getWidth() / 2) + insets.left); y = (int) (midY - (b * Math.sin(radialCurrent)) - (d.getHeight() / 2) + insets.top); // Set the component's size and position. c.setBounds(x, y, d.width, d.height); } radialCurrent += radialIncrement; } } } /** * Returns the class name. * * @return The class name. */ public String toString() { return getClass().getName(); } /** * Run a demonstration. * * @param args ignored. * * @throws Exception when an error occurs. */ public static void main(final String[] args) throws Exception { final Frame frame = new Frame(); final Panel panel = new Panel(); panel.setLayout(new RadialLayout()); panel.add(new Checkbox("One")); panel.add(new Checkbox("Two")); panel.add(new Checkbox("Three")); panel.add(new Checkbox("Four")); panel.add(new Checkbox("Five")); panel.add(new Checkbox("One")); panel.add(new Checkbox("Two")); panel.add(new Checkbox("Three")); panel.add(new Checkbox("Four")); panel.add(new Checkbox("Five")); frame.add(panel); frame.setSize(300, 500); frame.setVisible(true); } }