vector/vedit/cats.c

Go to the documentation of this file.

/*!
   \file lib/vector/vedit/cats.c
 
   \brief Vedit library - category manipulation
 
   (C) 2006-2008 by the GRASS Development Team
 
   This program is free software under the GNU General Public License
   (>=v2).  Read the file COPYING that comes with GRASS for details.
 
   \author Jachym Cepicky <jachym.cepicky gmail.com>
   \author Martin Landa <landa.martin gmail.com>
 */
 
#include <grass/glocale.h>
#include <grass/vedit.h>
 
/*!
   \brief Add / remove categories
 
   \param Map pointer to Map_info
   \param List list of selected primitives
   \param layer layer number
   \param del action (non-zero for delete otherwise add)
   \param Clist list of category numbers
 
   \return number of modified primitives
   \return -1 on error
 */
int Vedit_modify_cats(struct Map_info *Map, struct ilist *List, int layer,
                      int del, struct cat_list *Clist)
{
    int i, j;
    struct line_cats *Cats;
    struct line_pnts *Points;
    int line, type, cat;
    int nlines_modified, rewrite;
 
    /* features defined by cats */
    if (Clist->n_ranges <= 0) {
        return 0;
    }
 
    nlines_modified = 0;
 
    Cats = Vect_new_cats_struct();
    Points = Vect_new_line_struct();
 
    /* for each line, set new category */
    for (i = 0; i < List->n_values; i++) {
        line = List->value[i];
        type = Vect_read_line(Map, Points, Cats, line);
 
        if (!Vect_line_alive(Map, line))
            continue;
 
        rewrite = 0;
        for (j = 0; j < Clist->n_ranges; j++) {
            for (cat = Clist->min[j]; cat <= Clist->max[j]; cat++) {
                /* add new category */
                if (!del) {
                    if (Vect_cat_set(Cats, layer, cat) < 1) {
                        G_warning(
                            _("Unable to set category %d for (feature id %d)"),
                            cat, line);
                    }
                    else {
                        rewrite = 1;
                    }
                }
                else { /* delete old category */
                    if (Vect_field_cat_del(Cats, layer, cat) > 0) {
                        rewrite = 1;
                    }
                }
            }
        }
 
        if (rewrite == 0)
            continue;
 
        if (Vect_rewrite_line(Map, line, type, Points, Cats) < 0) {
            return -1;
        }
 
        nlines_modified++;
    }
 
    /* destroy structures */
    Vect_destroy_line_struct(Points);
    Vect_destroy_cats_struct(Cats);
 
    return nlines_modified;
}