Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * 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 3

 * 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.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.gui.beans.panelGroup;

import java.io.Serializable;

import java.util.ArrayList;

import org.gvsig.gui.beans.panelGroup.panels.AbstractPanel;

/**

 * <p>Implemented to use the {@link AbstractPanelGroup AbstractPanelGroup} type desired.</p>

 * <p>This class allows having different implementations of {@link AbstractPanelGroup AbstractPanelGroup}

 * and only load in memory the class of some of them, whom have previously been imported to future use. Then, when

 * a graphical interface would need use a <code>AbstractPanelGroup</code> instance, will instance an object of the 

 * class <i>selected</i> (set previously as <i>default</i>) of the registered types in this manager.</p> 

 * 

 * @version 18/10/2007

 * @author Pablo Piqueras Bartolom? (pablo.piqueras@iver.es) 

 */

public class PanelGroupManager implements Serializable {

        private static final long serialVersionUID = 2059085515913026734L;

        /**

         * Array list with the {@link AbstractPanelGroup AbstractPanelGroup} registered.

         * 

         * @see #registerPanelGroup(Class)

         * @see #deregisterPanelGroup(Class)

         */

        private ArrayList<Class> registeredPanelGroups = null;

        /**

         * The {@link AbstractPanelGroup AbstractPanelGroup} type set as default.

         * 

         * @see #getPanelGroup()

         * @see #setDefaultType(Class)

         */

        private Class defaultPanelGroup = null;

        /**

         * <p>Reference to the current manager with the <i>PanelGroup</i> registered.</p>

         */

        private static PanelGroupManager manager = null;

        /**

         * <p>Default constructor.</p>

         */

        protected PanelGroupManager() {

                 registeredPanelGroups = new ArrayList<Class>();

        }

        /**

         * <p>The singleton <code>PanelGroupManager</code> instance.</p>

         * 

         * @return current manager used, or if didn't exist any, a new one

         */

        public static synchronized PanelGroupManager getManager()

        {

                if( manager == null ) {

                        manager = new PanelGroupManager ();

                }

                return manager;

        }

        /**

         * <p>Registers a new {@link AbstractPanelGroup AbstractPanelGroup} class type if it

         * wasn't already done.</p>

         * 

         * @param panelGroup the new <code>AbstractPanelGroup</code> class type to register

         * 

         * @see #deregisterPanelGroup(Class)

         */

        public synchronized void registerPanelGroup(Class panelGroup) {

                // Only adds if isn't already registered

                if (!registeredPanelGroups.contains(panelGroup))

                        registeredPanelGroups.add(panelGroup);

        }

        /**

         * <p>Unregisters a {@link AbstractPanelGroup AbstractPanelGroup} class type if it

         * was previously registered.</p>

         * <p>If the type to unregister is the <i>default</i>, sets <i>default</i> to <code>null</code>.</p>

         * 

         * @param panelGroup the <code>AbstractPanelGroup</code> class type to unregister

         * 

         * @see #registerPanelGroup(Class)

         */

        public synchronized void deregisterPanelGroup(Class panelGroup) {

                // Only removes if already registered

                if (registeredPanelGroups.contains(panelGroup)) {

                        registeredPanelGroups.remove(panelGroup);

                        if (defaultPanelGroup == null)

                                return;

                        if (defaultPanelGroup.equals(panelGroup)) {

                                defaultPanelGroup = null;

                        }

                }

        }

        /**

         * <p>Sets as <i>default</i> one of the {@link AbstractPanelGroup AbstractPanelGroup} class type

         *  previously registered.</p>

         * 

         * @param panelGroup a <code>AbstractPanelGroup</code> class type

         * 

         * @see #getPanelGroup()

         */

        public synchronized void setDefaultType(Class panelGroup) {

                if (registeredPanelGroups.contains(panelGroup))

                        defaultPanelGroup = panelGroup;

        }

        /**

         * <p>Gets the <i>default</i> {@link AbstractPanelGroup AbstractPanelGroup} class type.</p>

         * 

         * return the <i>default</i> <code>AbstractPanelGroup</code> class type or <code>null</code> if isn't any

         * 

         * @throws Exception any exception produced loading the {@link AbstractPanel AbstractPanel}

         * 

         * @see #setDefaultType(Class)

         */        

        public synchronized AbstractPanelGroup getPanelGroup(Object reference) throws Exception {

                try {

                        if( defaultPanelGroup != null ) {

                                return (AbstractPanelGroup) defaultPanelGroup.getConstructor(Object.class).newInstance(reference);

                        }

                }

                catch (Exception e) {

                        throw e;

                }

                return null;

        }

}