Make mpp_to_zoom() a generic function

[andy/viking.git] / src / util.c

/*
 *    Viking - GPS data editor
 *    Copyright (C) 2007, Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
 *    Based on:
 *    Copyright (C) 2003-2007, Leandro A. F. Pereira <leandro@linuxmag.com.br>
 *
 *    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, version 2.
 *
 *    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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <glib/gi18n.h>
#include <glib/gprintf.h>

#include "util.h"
#include "dialog.h"

/*
#ifdef WINDOWS
#include <windows.h>
#endif

#ifndef WINDOWS
static gboolean spawn_command_line_async(const gchar * cmd,
                                         const gchar * arg)
{
  gchar *cmdline = NULL;
  gboolean status;

  cmdline = g_strdup_printf("%s '%s'", cmd, arg);
  g_debug("Running: %s", cmdline);
    
  status = g_spawn_command_line_async(cmdline, NULL);

  g_free(cmdline);
 
  return status;
}
#endif
*/

void open_url(GtkWindow *parent, const gchar * url)
{
  GError *error = NULL;
  gtk_show_uri ( gtk_widget_get_screen (GTK_WIDGET(parent)), url, GDK_CURRENT_TIME, &error );
  if ( error ) {
    a_dialog_error_msg_extra ( parent, _("Could not launch web browser. %s"), error->message );
    g_error_free ( error );
  }
}

void new_email(GtkWindow *parent, const gchar * address)
{
  gchar *uri = g_strdup_printf("mailto:%s", address);
  GError *error = NULL;
  gtk_show_uri ( gtk_widget_get_screen (GTK_WIDGET(parent)), uri, GDK_CURRENT_TIME, &error );
  if ( error ) {
    a_dialog_error_msg_extra ( parent, _("Could not create new email. %s"), error->message );
    g_error_free ( error );
  }
  /*
#ifdef WINDOWS
  ShellExecute(NULL, NULL, (char *) uri, NULL, ".\\", 0);
#else
  if (!spawn_command_line_async("xdg-email", uri))
    a_dialog_error_msg ( parent, _("Could not create new email.") );
#endif
  */
  g_free(uri);
  uri = NULL;
}
gchar *uri_escape(gchar *str)
{
  gchar *esc_str = g_malloc(3*strlen(str));
  gchar *dst = esc_str;
  gchar *src;

  for (src = str; *src; src++) {
    if (*src == ' ')
     *dst++ = '+';
    else if (g_ascii_isalnum(*src))
     *dst++ = *src;
    else {
      g_sprintf(dst, "%%%02hhX", *src);
      dst += 3;
    }
  }
  *dst = '\0';

  return(esc_str);
}


GList * str_array_to_glist(gchar* data[])
{
  GList *gl = NULL;
  gpointer * p;
  for (p = (gpointer)data; *p; p++)
    gl = g_list_prepend(gl, *p);
  return g_list_reverse(gl);
}

/**
 * split_string_from_file_on_equals:
 *
 * @buf: the input string
 * @key: newly allocated string that is before the '='
 * @val: newly allocated string after the '='
 *
 * Designed for file line processing, so it ignores strings beginning with special
 *  characters, such as '#'; returns false in such situations.
 * Also returns false if no equals character is found
 *
 * e.g. if buf = "GPS.parameter=42"
 *   key = "GPS.parameter"
 *   val = "42"
 */
gboolean split_string_from_file_on_equals ( const gchar *buf, gchar **key, gchar **val )
{
  // comments, special characters in viking file format
  if ( buf == NULL || buf[0] == '\0' || buf[0] == '~' || buf[0] == '=' || buf[0] == '#' )
    return FALSE;

  if ( ! strchr ( buf, '=' ) )
    return FALSE;

  gchar **strv = g_strsplit ( buf, "=", 2 );

  gint gi = 0;
  gchar *str = strv[gi];
  while ( str ) {
	if ( gi == 0 )
	  *key = g_strdup ( str );
	else
	  *val = g_strdup ( str );
    gi++;
    str = strv[gi];
  }

  g_strfreev ( strv );

  // Remove newline from val and also any other whitespace
  *key = g_strstrip ( *key );
  *val = g_strstrip ( *val );

  return TRUE;
}

/* 1 << (x) is like a 2**(x) */
#define GZ(x) (1<<(x))

static const gdouble scale_mpps[] = { GZ(0), GZ(1), GZ(2), GZ(3), GZ(4), GZ(5), GZ(6), GZ(7), GZ(8), GZ(9),
                                      GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15), GZ(16), GZ(17) };

static const gint num_scales = (sizeof(scale_mpps) / sizeof(scale_mpps[0]));

#define ERROR_MARGIN 0.01
guint8 mpp_to_zoom ( gdouble mpp )
{
  gint i;
  for ( i = 0; i < num_scales; i++ ) {
    if ( ABS(scale_mpps[i] - mpp) < ERROR_MARGIN ) {
      g_debug ( "mpp_to_zoom: %f -> %d", mpp, i );
      return i;
    }
  }
  // Handle mpp smaller than 1
  // return a useful value such that '17 - this number' gives a natural number.
  // Ideally should return '-1' or '0.5' but that's tricky with an unsigned int type!
  // (i.e. should rework to support zoom levels of 18 or 19)
  return 0;
}