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themeGrouping.cpp

Shows how to do a grouping on the objects of a TerraLib theme.

    /************************************************************************************
    TerraLib - a library for developing GIS applications.
    Copyright © 2001-2004 INPE and Tecgraf/PUC-Rio.

    This code is part of the TerraLib library.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.

    The authors reassure the license terms regarding the warranties.
    They specifically disclaim any warranties, including, but not limited to,
    the implied warranties of merchantability and fitness for a particular purpose.
    The library provided hereunder is on an "as is" basis, and the authors have no
    obligation to provide maintenance, support, updates, enhancements, or modifications.
    In no event shall INPE and Tecgraf / PUC-Rio be held liable to any party for direct,
    indirect, special, incidental, or consequential damages arising out of the use
    of this library and its documentation.
    *************************************************************************************/

    /*
               This file illustrates how to group objects of a theme. Each group of objects
               is associated to a legend.

               Authors: Karine Reis Ferreira
    */

    #include "../../src/terralib/kernel/TeLegendEntry.h"
    #include "../../src/terralib/drivers/MySQL/TeMySQL.h"

    int main()
    {
               // Datatabase server parameters
               string host = "localhost";
               string dbname = "DB320RC1";
               string user = "root";
               string password = "vinhas";

               // Open a connection to the DB320RC1 MySQL database
               TeDatabase* db = new TeMySQL();
               if (!db->connect(host, user, password, dbname))
               {
                          cout << "Error: " << db->errorMessage() << endl;
                          cout << endl << "Press Enter\n";
                          getchar();
                          return 1;
               }
               cout << "Connection successful to the database \"" << dbname << "\" on MySQL server \"" << host << "\" !\n";;

               // Load a previously created theme named T_dist.
               // This theme was created on a layer of the metropolitan districts of Sao Paulo city
               TeTheme* trmsp = new TeTheme("DistritosSaoPaulo");
               if (!db->loadTheme(trmsp))
               {
                   cout << "Fail to load the theme \"T_dist\": " << db->errorMessage() << endl;
                          db->close();
                          cout << endl << "Press Enter\n";
                          getchar();
            return 1;
               }
               trmsp->resetGrouping();                     // clear any grouping previously created

               TeAttributeRep rep;                         // grouping will be based on the attribute named "area_km2"
               rep.name_ = " area_km2 ";        // that contains the area of each metropolitan district
               rep.type_ = TeREAL;

               TeGrouping equalstep3;                                                       // define a particular way of grouping objects
               equalstep3.groupAttribute_ = rep;
               equalstep3.groupMode_ = TeEqualSteps;       // equal steps in 3 groups
               equalstep3.groupNumSlices_ = 3;
               if (!trmsp->buildGrouping(equalstep3))      // generate groups based on the grouping definition
               {
                   cout << "Fail to generate the groups: " << db->errorMessage() << endl;
                          db->close();
                          cout << endl << "Press Enter\n";
                          getchar();
            return 1;
               }

               // Associate a different visual to each group

               TeVisual visual(TePOLYGONS);                // group 1: dark green
               TeColor color(0,200,0);
               visual.color(color);
               trmsp->setGroupingVisual(1,&visual,TePOLYGONS);

               color.init(0,150,0);
               visual.color(color);             // group 2: medium green
               trmsp->setGroupingVisual(2,&visual,TePOLYGONS);

               color.init(0,100,0);
               visual.color(color);             // group 3: light red
               trmsp->setGroupingVisual(3,&visual,TePOLYGONS);

               if (!trmsp->saveGrouping())                            // save grouping definition
               {
                   cout << "Fail to save the grouping: " << db->errorMessage() << endl;
                          db->close();
                          cout << endl << "Press Enter\n";
                          getchar();
            return 1;
               }

               if (!trmsp->saveLegendInCollection())                             // save grouping definition
               {
                   cout << "Fail to save the grouping: " << db->errorMessage() << endl;
                          db->close();
                          cout << endl << "Press Enter\n";
                          getchar();
            return 1;
               }
               db->close();
               cout << "Theme was successfully grouped! " << endl;
               cout << endl << "Press Enter\n";
        getchar();
               return 0;
    }

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