ingo@1115: /*
ingo@1115:  * Copyright (c) 2010 by Intevation GmbH
ingo@1115:  *
ingo@1115:  * This program is free software under the LGPL (>=v2.1)
ingo@1115:  * Read the file LGPL.txt coming with the software for details
ingo@1115:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1115:  */
ingo@1115: 
sascha@484: package de.intevation.gnv.raster;
sascha@484: 
sascha@484: import org.apache.log4j.Logger;
sascha@484: 
sascha@484: /**
sascha@802:  * Converts the interal color index of a polygon to the external index
sascha@802:  * defined by the corresponding palette entry.
sascha@803:  *
sascha@780:  * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
sascha@484:  */
sascha@484: public class ExternalIndexConverter
sascha@484: implements   JTSMultiPolygonProducer.ValueConverter
sascha@484: {
sascha@484:     private static Logger log = Logger.getLogger(
sascha@484:         ExternalIndexConverter.class);
sascha@484: 
sascha@802:     /**
sascha@802:      * The palette where to find the color indices.
sascha@802:      */
sascha@484:     protected Palette palette;
sascha@484: 
sascha@802:     /**
sascha@802:      * Default constructor.
sascha@802:      */
sascha@484:     public ExternalIndexConverter() {
sascha@484:     }
sascha@484: 
sascha@802:     /**
sascha@802:      * Constrcutor to create an ExternalIndexConverter with
sascha@802:      * a given palette.
sascha@802:      * @param palette The palette where to find the color indices.
sascha@802:      */
sascha@484:     public ExternalIndexConverter(Palette palette) {
sascha@484:         this.palette = palette;
sascha@484:     }
sascha@484: 
sascha@802:     /**
sascha@802:      * Maps the color index of a polygon to the external index
sascha@802:      * defined by the corresponing palette entry.
sascha@802:      * @param value The value to convert
sascha@802:      * @return The mapped value or the original value if
sascha@802:      * no corresponing palette entry was found.
sascha@802:      */
sascha@484:     public Integer convert(Integer value) {
sascha@484:         if (value == null) {
sascha@484:             return value;
sascha@484:         }
sascha@484: 
sascha@484:         int v = value.intValue();
sascha@484: 
sascha@484:         if (v == -1) {
sascha@484:             return value;
sascha@484:         }
sascha@484: 
sascha@484:         Palette.Entry entry = palette.getEntryByIndex(v);
sascha@484: 
sascha@484:         if (entry == null) {
sascha@484:             log.warn("cannot find palette entry for index: " + v);
sascha@484:             return value;
sascha@484:         }
sascha@484: 
sascha@484:         return Integer.valueOf(entry.getExternalIndex());
sascha@484:     }
sascha@484: }
sascha@484: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :