Java tutorial
/* * Java Terrain and Stellar System Ports * * Copyright (C) 2006 Martin H. Smith based on work by original * authors. * * Released under the terms of the GNU General Public License * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, * MA 02110-1301, USA. * * Linking TerraJ statically or dynamically with other modules is making a * combined work based on TerraJ. Thus, the terms and conditions of the * GNU General Public License cover the whole combination. * * In addition, as a special exception, the copyright holders of TerraJ * give you permission to combine this program with free software programs * or libraries that are released under the GNU LGPL and with code included * in the standard release of JOGL, Java Getopt and FreeMarker under the BSD * license (or modified versions of such code, with unchanged license) and with * Apache Commons and Log4J libraries under the Apache license (or modified versions * of such code. You may copy and distribute such a system following the terms * of the GNU GPL for TerraJ and the licenses of the other code concerned, * provided that you include the source code of that other code when and as the * GNU GPL requires distribution of source code. * * Note that people who make modified versions of TerraJ are not obligated to grant * this special exception for their modified versions; it is their choice whether * to do so. The GNU General Public License gives permission to release a modified * version without this exception; this exception also makes it possible to release * a modified version which carries forward this exception. */ /* * ProjectionManager.java * * Created on 22 January 2006, 12:09 */ package com.alvermont.terraj.planet.project; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.Map; import java.util.SortedSet; import java.util.TreeSet; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Class that manages a list of available projections. * * @author martin * @version $Id: ProjectionManager.java,v 1.6 2006/07/06 06:58:34 martin Exp $ */ public class ProjectionManager { /** Our logger object */ private static Log log = LogFactory.getLog(ProjectionManager.class); // RequireThis OFF: log /** The set of projections we know about */ private SortedSet<Projector> projections; /** Map of names to projections */ private Map<String, Projector> nameMap = new HashMap<String, Projector>(); /** Map of thumbnail names to projections */ private Map<String, Projector> thumbMap = new HashMap<String, Projector>(); /** * A comparator to sort projections into alphabetical order by name * * @param o1 The first object to be compared * @param o2 The second object to be compared */ private class ProjectorComparator implements Comparator<Projector> { public ProjectorComparator() { } public int compare(Projector o1, Projector o2) { if (o1 == o2) { return 0; } return o1.toString().compareTo(o2.toString()); } } /** The list of built in projections */ private final Projector[] defaultProjections = { new AzimuthProjection(), new ConicalProjection(), new GnomonicProjection(), new MercatorProjection(), new MollweideProjection(), new OrthographicProjection(), new PetersProjection(), new SinusoidProjection(), new SquareProjection(), new StereographicProjection() }; /** Creates a new instance of ProjectionManager */ public ProjectionManager() { this.projections = new TreeSet<Projector>(new ProjectorComparator()); for (Projector p : this.defaultProjections) { log.debug("Projection: " + p + " " + (p instanceof Projector)); this.projections.add((Projector) p); this.nameMap.put(p.toString(), p); this.thumbMap.put(p.getThumbnailName(), p); } } /** * Get a set containing all the projections we know about, sorted into * alphabetical order * * @return A sorted set of the projections this object is managing */ public synchronized SortedSet<Projector> getProjections() { return Collections.unmodifiableSortedSet(this.projections); } /** * Add a projection to the set being managed * * @param proj An object that implements the <code>Projector</code> * interface that will be added to the available set */ public synchronized void addProjection(Projector proj) { this.projections.add(proj); } /** * Removes a projection from the set being managed * * @param proj An object that implements the <code>Projector</code> * interface that will be removed from the available set */ public synchronized void removeProjection(Projector proj) { this.projections.remove(proj); } /** * Look up a projection by its name * * @param name The name of the projection to retrieve * @return The corresponding projection or <code>null</code> if it * doesn't exist */ public synchronized Projector findByName(String name) { return this.nameMap.get(name); } /** * Get a default projection that can be used e.g. if searches fail * * @return A projection object suitable for returning as a default */ public Projector getDefaultProjection() { return findByName("Orthographic Projection"); } /** * Look up a projection by the name of its thumbnail * * @param name The name of the projection to retrieve * @return The corresponding projection or <code>null</code> if it * doesn't exist */ public synchronized Projector findByThumbnailName(String name) { return this.thumbMap.get(name); } /** * Format a thumbnail fName into a string suitable for use in a * call to <code>getResource</code>. If the object does not have a * package then we default it to ours and if does not have an extension * then we default it to PNG. * * @param name The fName of the thumbnail * @return A string that can be used to load the thumbnail as a resource */ public String formatThumbnailName(final String name) { String fName = name; // first default the package if (fName.indexOf('/') < 0) { // turn our package fName into a path String ourpkg = getClass().getPackage().getName() + ".images"; ourpkg = "/" + ourpkg.replace('.', '/'); fName = ourpkg + "/" + fName; } // now add an extension if necessary if (fName.indexOf('.') < 0) { fName += ".png"; } return fName; } }