| gvSIG desktop 1

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

 *

 * Copyright (C) 2007 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.

 */

package org.gvsig.raster.dataset.properties;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.Reader;

import java.io.StringReader;

import org.gvsig.raster.dataset.io.rmf.ClassSerializer;

import org.gvsig.raster.dataset.io.rmf.ParsingException;

import org.gvsig.raster.util.Histogram;

import org.gvsig.raster.util.HistogramClass;

import org.kxml2.io.KXmlParser;

import org.xmlpull.v1.XmlPullParserException;

/**

 * <P>

 * Clase para convertir a XML un histograma y obtener el histograma desde XML.

 * Esta clase implementa el interfaz IRmfBlock con los m?todos de escritura y 

 * lectura. Estos ser?n utilizados por el gestor de ficheros RMF para escribir y

 * leer datos.

 * </P>

 * <P>

 * La estructura XML de un histograma es la siguiente:

 * </P>

 * <P>

 *\<Histogram\> <BR>

 *&nbsp;\<ClassInterval\>1.0\</ClassInterval\><BR>

 *&nbsp;\<Min\>0.0\</Min\><BR>

 *&nbsp;\<Max\>255.0\</Max\><BR>

 *&nbsp;\<BandCount\>3\</BandCount\><BR>

 *&nbsp;\<Band\><BR>

 *&nbsp;&nbsp;\<Values\>13 2 0 ... 2 1 6\</Values\><BR>

 *&nbsp;\</Band\><BR>

 *&nbsp;\<Band\><BR>

 *&nbsp;&nbsp;\<Values\>6 2 2 ... 3 2 8\</Values\><BR>

 *&nbsp;\</Band\><BR>

 *&nbsp;\<Band\><BR>

 *&nbsp;&nbsp;\<Values\>16 1 1 ... 1 1 9\</Values\><BR>

 *&nbsp;\</Band\><BR\>

 *\</Histogram\><BR>

 *\</P\>

 * @version 23/04/2007

 * @author Nacho Brodin (nachobrodin@gmail.com)

 *

 */

public class HistogramRmfSerializer extends ClassSerializer {

        //TAGS

        public static final String MAIN_TAG = "Histogram";

        public static final String CLASSINTERVAL = "ClassInterval";

        public static final String MIN = "Min";

        public static final String MAX = "Max";

        public static final String BAND = "Band";

        public static final String VALUES = "Values";

        public static final String BAND_COUNT = "BandCount";

        private Histogram  histogram = null;

        /**

         * Constructor. Asigna el histograma a serializar.

         * @param Histogram histograma a convertir en XML

         */

        public HistogramRmfSerializer(Histogram hist) {

                this.histogram = hist;

        }

        /**

         * Constructor. 

         */

        public HistogramRmfSerializer() {

        }

        /**

         * Convierte una lista de valores en un solo String en un array de long

         * @param list Cadena con la lista de valores

         * @return Array de valores long

         * @throws XmlPullParserException

         * @throws IOException

         */

        private long[] parseLongList(String list) throws XmlPullParserException, IOException {

                String[] sValues = list.split(" ");

                long[] dValues = new long[sValues.length];

                for (int i = 0; i < sValues.length; i++) 

                        dValues[i] = Long.parseLong(sValues[i]);

                return dValues;

        }

        /**

         * Parsea el tag Band para extraer la lista de valores (Values) asociada a una banda. 

         * @param parser KXmlParser

         * @return Array de long

         * @throws XmlPullParserException

         * @throws IOException

         */

        private long[] parserHistogramListValues(KXmlParser parser)  throws XmlPullParserException, IOException {

                long[] valueList = null;

                boolean end = false;

                boolean tagOk = false;

            int tag = parser.next();

            while (!end) {

                    switch(tag) {

                        case KXmlParser.START_TAG:

                                if(parser.getName() != null) {        

                                                if (parser.getName().compareTo(VALUES) == 0)

                                                        tagOk = true;

                                        }                                

                                        break;

                         case KXmlParser.END_TAG:

                                 if (parser.getName().compareTo(BAND) == 0)

                                         end = true;

                                break;

                        case KXmlParser.TEXT:

                                if(tagOk) {

                                        valueList = parseLongList(parser.getText());

                                        tagOk = false;

                                }

                                break;

                    }

                    if (!end)

                            tag = parser.next();

            }

            return valueList;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.dataset.io.rmf.IRmfBlock#read(java.lang.String)

         */

        public void read(String xml) throws ParsingException {        

                double interval = 0D;

                double min = 0D;

                double max = 0D;

                int numBands = 0;

                long[][] values = null;

                KXmlParser parser = new KXmlParser();

                Reader reader = new StringReader(xml);

                try {

                        parser.setInput(reader);

                } catch (XmlPullParserException e) {

                        throw new ParsingException(xml);

                }

                try {

                        int tag = parser.nextTag();

                        if ( parser.getEventType() != KXmlParser.END_DOCUMENT ){                    

                                parser.require(KXmlParser.START_TAG, null, MAIN_TAG);                            

                                while(tag != KXmlParser.END_DOCUMENT) {

                                        switch(tag) {

                                                case KXmlParser.START_TAG:

                                                        if(parser.getName() != null) {         

                                                                if (parser.getName().compareTo(MAIN_TAG) == 0) {

                                                                        interval = Double.parseDouble(parserString(parser, CLASSINTERVAL));

                                                                        min = Double.parseDouble(parserString(parser, MIN));

                                                                        max = Double.parseDouble(parserString(parser, MAX));

                                                                        numBands = (int)Double.parseDouble(parserString(parser, BAND_COUNT));

                                                                        values = new long[numBands][];

                                                                        for (int iBand = 0; iBand < numBands; iBand++) 

                                                                                values[iBand] = parserHistogramListValues(parser);

                                                                }

                                                        }        

                                                        break;

                                                case KXmlParser.END_TAG:                                                                

                                                        break;

                                                case KXmlParser.TEXT:                                                        

                                                        break;

                                        }

                                        tag = parser.next();

                                }

                                parser.require(KXmlParser.END_DOCUMENT, null, null);

                        }

                } catch (XmlPullParserException e) {

                        throw new ParsingException(xml);

                } catch (IOException e) {

                        throw new ParsingException(xml);

                }

                histogram = new Histogram(numBands, values[0].length, min, max);

                histogram.setTable(values);

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.dataset.io.rmf.IRmfBlock#write()

         */

        public String write() {

                StringBuffer b = new StringBuffer();

                HistogramClass[][] c = histogram.getHistogram();

                b.append("<" + MAIN_TAG + ">\n");

                b.append("\t<" + CLASSINTERVAL  + ">");

                double interval = c[0][0].getMax() - c[0][0].getMin();

                b.append(interval);

                b.append("</" + CLASSINTERVAL + ">\n");

                b.append("\t<" + MIN + ">");

                b.append(c[0][0].getMin());

                b.append("</" + MIN + ">\n");

                b.append("\t<" + MAX + ">");

                b.append(c[0][c[0].length - 1].getMax());

                b.append("</" + MAX + ">\n");

                b.append("\t<" + BAND_COUNT + ">");

                b.append(histogram.getNumBands());

                b.append("</" + BAND_COUNT + ">\n");

                for (int iBand = 0; iBand < histogram.getNumBands(); iBand++) {

                        b.append("\t<" + BAND + ">\n");

                        b.append("\t\t<" + VALUES + ">");

                        for (int iValues = 0; iValues < histogram.getNumValues(); iValues++)

                                b.append((long)histogram.getHistogramValueByPos(iBand, iValues) + " ");

                        b.append("</" + VALUES + ">\n");

                        b.append("\t</" + BAND + ">\n");

                }

                b.append("</" + MAIN_TAG + ">");

                return b.toString();

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.dataset.io.rmf.IRmfBlock#getResult()

         */

        public Object getResult() {

                return (Histogram)histogram;

        }

        /*

         *  (non-Javadoc)

         * @see org.gvsig.raster.dataset.io.rmf.IRmfBlock#getMainTag()

         */

        public String getMainTag() {

                return MAIN_TAG;

        }

}