Application: gvSIG desktop

/*

 * Created on 20-sep-2005

 *

 * To change the template for this generated file go to

 * Window>Preferences>Java>Code Generation>Code and Comments

 */

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package org.gvsig.georeferencing.utils;

import java.util.ArrayList;

import org.cresques.px.Extent;

import com.iver.cit.gvsig.fmap.layers.IStackZoom;

/**

 * Clase para almacenar los extents que se van seleccionando al manipular

 * una imagen para su georreferenciaci?n. Esto permite recuperar extents anteriores.

 * 

 * @author Nacho Brodin (brodin_ign@gva.es)

 */

public class StackZoom implements IStackZoom{

        //**********************Vars****************************************

        /**

         * N?mero m?ximo de elementos en la pila

         */

        private static final int                MAX = 10;

        private ArrayList                                 extentList = new ArrayList();

        private Extent                                         initExtent = null;        

        private int                                         selectElem = -1;

        private int                                                top = -1;

        //**********************End Vars************************************

        //**********************Methods*************************************

        public StackZoom(){}

        /**

         * Vacia la pila de Extents

         */

        public void clear(){

          extentList.clear();        

          selectElem = 0;

        }

        //**********************End Methods**********************************

        //**********************Setters & Getters****************************

        /**

         * A?ade un extent a la lista

         * @param ext

         */

        public void setZoom(Extent ext){

                if(selectElem < (MAX - 1)){

                        if(selectElem == top)

                                top++;

                        else

                                top = selectElem + 1;

                        selectElem ++;

                        extentList.add(selectElem, ext);

                }

        }

        /**

         * Recupera el ?ltimo extent aplicado. 

         * <P>Si la pila est? vacia o est? situada en el primer

         * elemento devuelve null sino devuelve el Extent guardado anterior al actual.</P>

         * @return Extent anterior.

         */

        public Extent getLastZoom(){

                if(extentList.size() == 0)

                        return null;

                if(selectElem  == -1)

                        return null;

                selectElem --;

                Extent ex = null;

                try{        

                        ex = (Extent)extentList.get(selectElem);

                }catch (ArrayIndexOutOfBoundsException exc){

                        //Elemento recuperado valdr? null y colocamos el puntero en el primer elemento

                        selectElem = 0;

                        System.err.println("Zoom Stack Empty");

                }

                return ex;

        }

        /**

         * Recupera el siguiente zoom. Se usa cuando se ha recuperado el ?ltimo

         * zoom y se quiere volver al siguiente.

         * <P>Si estamos en el tope de la pila o hemos llegado a su m?xima capacidad o no tiene

         * elementos devuelve null sino devuelve el siguiente</P>

         *   

         * @return

         */

        public Extent getNextZoom(){

                if(        selectElem == (MAX -1) ||

                        selectElem == top || 

                        extentList.size() == 0 )

                        return null;

                selectElem ++;

                Extent ex = null;

                try{

                        ex = (Extent)extentList.get(selectElem);

                }catch (ArrayIndexOutOfBoundsException exc){

                        //No hacemos nada y el elemento recuperado valdr? null

                        System.err.println("Zoom Stack On Top");

                }

                return ex;

        }

        /**

         * @return Returns the initExtent.

         */

        public Extent getInitExtent() {

                return initExtent;

        }

        /**

         * @param initExtent The initExtent to set.

         */

        public void setInitExtent(Extent initExtent, boolean incr) {

                if(incr)

                        selectElem ++;

                extentList.add(0, initExtent);

                this.initExtent = initExtent;

        }

        /**

         * Obtiene el apuntador a elementos

         * @return 

         */

        public int getSelectElem() {

                return selectElem;

        }

        /**

         * Obtiene el n?mero de elementos de la pila

         * @return N?mero de elementos de la pila

         */

        public int getStackSize(){

                return top;

        }

        //**********************End Setters & Getters************************

}