src/file.c

   1 /*
   2  * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
   3  *
   4  * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include "viking.h"
  26
  27 #include "gpx.h"
  28
  29 #include <string.h>
  30 #include <stdlib.h>
  31 #include <glib.h>
  32 #include <glib/gstdio.h>
  33
  34 #define TEST_BOOLEAN(str) (! ((str)[0] == '\0' || (str)[0] == '0' || (str)[0] == 'n' || (str)[0] == 'N' || (str)[0] == 'f' || (str)[0] == 'F') )
  35 #define VIK_MAGIC "#VIK"
  36 #define GPX_MAGIC "<?xm"
  37 #define VIK_MAGIC_LEN 4
  38
  39 #ifdef WINDOWS
  40 #define FILE_SEP '\\'
  41 #else
  42 #define FILE_SEP '/'
  43 #endif
  44
  45 typedef struct _Stack Stack;
  46
  47 struct _Stack {
  48   Stack *under;
  49   gpointer *data;
  50 };
  51
  52 static void pop(Stack **stack) {
  53   Stack *tmp = (*stack)->under;
  54   g_free ( *stack );
  55   *stack = tmp;
  56 }
  57
  58 static void push(Stack **stack)
  59 {
  60   Stack *tmp = g_malloc ( sizeof ( Stack ) );
  61   tmp->under = *stack;
  62   *stack = tmp;
  63 }
  64
  65 static gboolean check_magic ( FILE *f, const gchar *magic_number )
  66 {
  67   gchar magic[VIK_MAGIC_LEN];
  68   gboolean rv = FALSE;
  69   gint8 i;
  70   if ( fread(magic, 1, sizeof(magic), f) == sizeof(magic) &&
  71       strncmp(magic, magic_number, sizeof(magic)) == 0 )
  72     rv = TRUE;
  73   for ( i = sizeof(magic)-1; i >= 0; i-- ) /* the ol' pushback */
  74     ungetc(magic[i],f);
  75   return rv;
  76 }
  77
  78
  79 static gboolean str_starts_with ( const gchar *haystack, const gchar *needle, guint16 len_needle, gboolean must_be_longer )
  80 {
  81   if ( strlen(haystack) > len_needle - (!must_be_longer) && strncasecmp ( haystack, needle, len_needle ) == 0 )
  82     return TRUE;
  83   return FALSE;
  84 }
  85
  86 static guint16 layer_type_from_string ( const gchar *str )
  87 {
  88   guint8 i;
  89   for ( i = 0; i < VIK_LAYER_NUM_TYPES; i++ )
  90     if ( strcasecmp ( str, vik_layer_get_interface(i)->name ) == 0 )
  91       return i;
  92   return -1;
  93 }
  94
  95 static void write_layer_params_and_data ( VikLayer *l, FILE *f )
  96 {
  97   VikLayerParam *params = vik_layer_get_interface(l->type)->params;
  98   VikLayerFuncGetParam get_param = vik_layer_get_interface(l->type)->get_param;
  99
 100   fprintf ( f, "name=%s\n", l->name ? l->name : "" );
 101   if ( !l->visible )
 102     fprintf ( f, "visible=f\n" );
 103
 104   if ( params && get_param )
 105   {
 106     VikLayerParamData data;
 107     guint16 i, params_count = vik_layer_get_interface(l->type)->params_count;
 108     for ( i = 0; i < params_count; i++ )
 109     {
 110       data = get_param(l,i);
 111
 112       /* string lists are handled differently. We get a GList (that shouldn't
 113        * be freed) back for get_param and if it is null we shouldn't write
 114        * anything at all (otherwise we'd read in a list with an empty string,
 115        * not an empty string list.
 116        */
 117       if ( params[i].type == VIK_LAYER_PARAM_STRING_LIST ) {
 118         if ( data.sl ) {
 119           GList *iter = (GList *)data.sl;
 120           while ( iter ) {
 121             fprintf ( f, "%s=", params[i].name );
 122             fprintf ( f, "%s\n", (gchar *)(iter->data) );
 123             iter = iter->next;
 124           }
 125         }
 126       } else {
 127         fprintf ( f, "%s=", params[i].name );
 128         switch ( params[i].type )
 129         {
 130           case VIK_LAYER_PARAM_DOUBLE: {
 131   //          char buf[15]; /* locale independent */
 132   //          fprintf ( f, "%s\n", (char *) g_dtostr (data.d, buf, sizeof (buf)) ); break;
 133               fprintf ( f, "%f\n", data.d );
 134               break;
 135          }
 136           case VIK_LAYER_PARAM_UINT: fprintf ( f, "%d\n", data.u ); break;
 137           case VIK_LAYER_PARAM_INT: fprintf ( f, "%d\n", data.i ); break;
 138           case VIK_LAYER_PARAM_BOOLEAN: fprintf ( f, "%c\n", data.b ? 't' : 'f' ); break;
 139           case VIK_LAYER_PARAM_STRING: fprintf ( f, "%s\n", data.s ); break;
 140           case VIK_LAYER_PARAM_COLOR: fprintf ( f, "#%.2x%.2x%.2x\n", (int)(data.c.red/256),(int)(data.c.green/256),(int)(data.c.blue/256)); break;
 141         }
 142       }
 143     }
 144   }
 145   if ( vik_layer_get_interface(l->type)->write_file_data )
 146   {
 147     fprintf ( f, "\n\n~LayerData\n" );
 148     vik_layer_get_interface(l->type)->write_file_data ( l, f );
 149     fprintf ( f, "~EndLayerData\n" );
 150   }
 151   /* foreach param:
 152      write param, and get_value, etc.
 153      then run layer data, and that's it.
 154   */
 155 }
 156
 157 static void file_write ( VikAggregateLayer *top, FILE *f, gpointer vp )
 158 {
 159   Stack *stack = NULL;
 160   VikLayer *current_layer;
 161   struct LatLon ll;
 162   gchar *modestring;
 163
 164   push(&stack);
 165   stack->data = (gpointer) vik_aggregate_layer_get_children(VIK_AGGREGATE_LAYER(top));
 166   stack->under = NULL;
 167
 168   /* crazhy CRAZHY */
 169   vik_coord_to_latlon ( vik_viewport_get_center ( VIK_VIEWPORT(vp) ), &ll );
 170
 171   switch ( vik_viewport_get_drawmode ( VIK_VIEWPORT(vp) ) ) {
 172     case VIK_VIEWPORT_DRAWMODE_UTM: modestring = "utm"; break;
 173     case VIK_VIEWPORT_DRAWMODE_EXPEDIA: modestring = "expedia"; break;
 174     case VIK_VIEWPORT_DRAWMODE_GOOGLE: modestring = "google"; break;
 175     case VIK_VIEWPORT_DRAWMODE_KH: modestring = "kh"; break;
 176     default: modestring = "mercator";
 177   }
 178
 179   fprintf ( f, "#VIKING GPS Data file " VIKING_URL "\n\nxmpp=%f\nympp=%f\nlat=%f\nlon=%f\nmode=%s\ncolor=%s\ndrawscale=%s\ndrawcentermark=%s",
 180       vik_viewport_get_xmpp ( VIK_VIEWPORT(vp) ), vik_viewport_get_ympp ( VIK_VIEWPORT(vp) ), ll.lat, ll.lon,
 181       modestring, vik_viewport_get_background_color(VIK_VIEWPORT(vp)),
 182       vik_viewport_get_draw_scale(VIK_VIEWPORT(vp)) ? "t" : "f",
 183       vik_viewport_get_draw_centermark(VIK_VIEWPORT(vp)) ? "t" : "f" );
 184
 185   if ( ! VIK_LAYER(top)->visible )
 186     fprintf ( f, "visible=f\n" );
 187
 188   while (stack && stack->data)
 189   {
 190     current_layer = VIK_LAYER(((GList *)stack->data)->data);
 191     fprintf ( f, "\n~Layer %s\n", vik_layer_get_interface(current_layer->type)->name );
 192     write_layer_params_and_data ( current_layer, f );
 193     if ( current_layer->type == VIK_LAYER_AGGREGATE && !vik_aggregate_layer_is_empty(VIK_AGGREGATE_LAYER(current_layer)) )
 194     {
 195       push(&stack);
 196       stack->data = (gpointer) vik_aggregate_layer_get_children(VIK_AGGREGATE_LAYER(current_layer));
 197     }
 198     else if ( current_layer->type == VIK_LAYER_GPS && !vik_gps_layer_is_empty(VIK_GPS_LAYER(current_layer)) )
 199     {
 200       push(&stack);
 201       stack->data = (gpointer) vik_gps_layer_get_children(VIK_GPS_LAYER(current_layer));
 202     }
 203     else
 204     {
 205       stack->data = (gpointer) ((GList *)stack->data)->next;
 206       fprintf ( f, "~EndLayer\n\n" );
 207       while ( stack && (!stack->data) )
 208       {
 209         pop(&stack);
 210         if ( stack )
 211         {
 212           stack->data = (gpointer) ((GList *)stack->data)->next;
 213           fprintf ( f, "~EndLayer\n\n" );
 214         }
 215       }
 216     }
 217   }
 218 /*
 219   get vikaggregatelayer's children (?)
 220   foreach write ALL params,
 221   then layer data (IF function exists)
 222   then endlayer
 223
 224   impl:
 225   stack of layers (LIST) we are working on
 226   when layer->next == NULL ...
 227   we move on.
 228 */
 229 }
 230
 231 static void string_list_delete ( gpointer key, gpointer l, gpointer user_data )
 232 {
 233   GList *iter = (GList *) iter;
 234   while ( iter ) {
 235     g_free ( iter->data );
 236     iter = iter->next;
 237   }
 238   g_list_free ( (GList *) iter );
 239 }
 240
 241 static void string_list_set_param (gint i, GList *list, gpointer *layer_and_vp)
 242 {
 243   VikLayerParamData x;
 244   x.sl = list;
 245   vik_layer_set_param ( VIK_LAYER(layer_and_vp[0]), i, x, layer_and_vp[1] );
 246 }
 247
 248 static void file_read ( VikAggregateLayer *top, FILE *f, VikViewport *vp )
 249 {
 250   Stack *stack;
 251   struct LatLon ll = { 0.0, 0.0 };
 252   gchar buffer[4096];
 253   gchar *line;
 254   guint16 len;
 255   long line_num = 0;
 256
 257   VikLayerParam *params = NULL; /* for current layer, so we don't have to keep on looking up interface */
 258   guint8 params_count = 0;
 259
 260   GHashTable *string_lists = g_hash_table_new(g_direct_hash,g_direct_equal);
 261
 262   push(&stack);
 263   stack->under = NULL;
 264   stack->data = (gpointer) top;
 265
 266   while ( fgets ( buffer, 4096, f ) )
 267   {
 268     line_num++;
 269
 270     line = buffer;
 271     while ( *line == ' ' || *line =='\t' )
 272       line++;
 273
 274     if ( line[0] == '#' )
 275       continue;
 276
 277
 278     len = strlen(line);
 279     if ( len > 0 && line[len-1] == '\n' )
 280       line[--len] = '\0';
 281     if ( len > 0 && line[len-1] == '\r' )
 282       line[--len] = '\0';
 283
 284     if ( len == 0 )
 285       continue;
 286
 287
 288     if ( line[0] == '~' )
 289     {
 290       line++; len--;
 291       if ( *line == '\0' )
 292         continue;
 293       else if ( str_starts_with ( line, "Layer ", 6, TRUE ) )
 294       {
 295         int parent_type = VIK_LAYER(stack->data)->type;
 296         if ( ( ! stack->data ) || ((parent_type != VIK_LAYER_AGGREGATE) && (parent_type != VIK_LAYER_GPS)) )
 297         {
 298           g_warning ( "Line %ld: Layer command inside non-Aggregate Layer (type %d)", line_num, parent_type );
 299           push(&stack); /* inside INVALID layer */
 300           stack->data = NULL;
 301           continue;
 302         }
 303         else
 304         {
 305           gint16 type = layer_type_from_string ( line+6 );
 306           push(&stack);
 307           if ( type == -1 )
 308           {
 309             g_warning ( "Line %ld: Unknown type %s\n", line_num, line+6 );
 310             stack->data = NULL;
 311           }
 312           else if (parent_type == VIK_LAYER_GPS)
 313           {
 314             stack->data = (gpointer) vik_gps_layer_get_a_child(VIK_GPS_LAYER(stack->under->data));
 315             params = vik_layer_get_interface(type)->params;
 316             params_count = vik_layer_get_interface(type)->params_count;
 317           }
 318           else
 319           {
 320             stack->data = (gpointer) vik_layer_create ( type, vp, NULL, FALSE );
 321             params = vik_layer_get_interface(type)->params;
 322             params_count = vik_layer_get_interface(type)->params_count;
 323           }
 324         }
 325       }
 326       else if ( str_starts_with ( line, "EndLayer", 8, FALSE ) )
 327       {
 328         if ( stack->under == NULL )
 329           g_warning ( "Line %ld: Mismatched ~EndLayer command", line_num );
 330         else
 331         {
 332           /* add any string lists we've accumulated */
 333           gpointer layer_and_vp[2];
 334           layer_and_vp[0] = stack->data;
 335           layer_and_vp[1] = vp;
 336           g_hash_table_foreach ( string_lists, (GHFunc) string_list_set_param, layer_and_vp );
 337           g_hash_table_remove_all ( string_lists );
 338
 339           if ( stack->data && stack->under->data )
 340           {
 341             if (VIK_LAYER(stack->under->data)->type == VIK_LAYER_AGGREGATE) {
 342               vik_aggregate_layer_add_layer ( VIK_AGGREGATE_LAYER(stack->under->data), VIK_LAYER(stack->data) );
 343               vik_layer_post_read ( VIK_LAYER(stack->data), vp, TRUE );
 344             }
 345             else if (VIK_LAYER(stack->under->data)->type == VIK_LAYER_GPS) {
 346               /* TODO: anything else needs to be done here ? */
 347             }
 348             else
 349               g_warning ( "Line %ld: EndLayer command inside non-Aggregate Layer (type %d)", line_num, VIK_LAYER(stack->data)->type );
 350           }
 351           pop(&stack);
 352         }
 353       }
 354       else if ( str_starts_with ( line, "LayerData", 9, FALSE ) )
 355       {
 356         if ( stack->data && vik_layer_get_interface(VIK_LAYER(stack->data)->type)->read_file_data )
 357           vik_layer_get_interface(VIK_LAYER(stack->data)->type)->read_file_data ( VIK_LAYER(stack->data), f );
 358           /* must read until hits ~EndLayerData */
 359
 360         else
 361         { /* simply skip layer data over */
 362           while ( fgets ( buffer, 4096, f ) )
 363           {
 364             line_num++;
 365
 366             line = buffer;
 367
 368             len = strlen(line);
 369             if ( len > 0 && line[len-1] == '\n' )
 370               line[--len] = '\0';
 371             if ( len > 0 && line[len-1] == '\r' )
 372               line[--len] = '\0';
 373             if ( strcasecmp ( line, "~EndLayerData" ) == 0 )
 374               break;
 375           }
 376           continue;
 377         }
 378       }
 379       else
 380       {
 381         g_warning ( "Line %ld: Unknown tilde command", line_num );
 382       }
 383     }
 384     else
 385     {
 386       gint32 eq_pos = -1;
 387       guint16 i;
 388       if ( ! stack->data )
 389         continue;
 390
 391       for ( i = 0; i < len; i++ )
 392         if ( line[i] == '=' )
 393           eq_pos = i;
 394
 395       if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "xmpp", eq_pos ) == 0) /* "hard coded" params: global & for all layer-types */
 396         vik_viewport_set_xmpp ( VIK_VIEWPORT(vp), strtod ( line+5, NULL ) );
 397       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "ympp", eq_pos ) == 0)
 398         vik_viewport_set_ympp ( VIK_VIEWPORT(vp), strtod ( line+5, NULL ) );
 399       else if ( stack->under == NULL && eq_pos == 3 && strncasecmp ( line, "lat", eq_pos ) == 0 )
 400         ll.lat = strtod ( line+4, NULL );
 401       else if ( stack->under == NULL && eq_pos == 3 && strncasecmp ( line, "lon", eq_pos ) == 0 )
 402         ll.lon = strtod ( line+4, NULL );
 403       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "mode", eq_pos ) == 0 && strcasecmp ( line+5, "utm" ) == 0)
 404         vik_viewport_set_drawmode ( VIK_VIEWPORT(vp), VIK_VIEWPORT_DRAWMODE_UTM);
 405       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "mode", eq_pos ) == 0 && strcasecmp ( line+5, "expedia" ) == 0)
 406         vik_viewport_set_drawmode ( VIK_VIEWPORT(vp), VIK_VIEWPORT_DRAWMODE_EXPEDIA );
 407       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "mode", eq_pos ) == 0 && strcasecmp ( line+5, "google" ) == 0)
 408         vik_viewport_set_drawmode ( VIK_VIEWPORT(vp), VIK_VIEWPORT_DRAWMODE_GOOGLE );
 409       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "mode", eq_pos ) == 0 && strcasecmp ( line+5, "kh" ) == 0)
 410         vik_viewport_set_drawmode ( VIK_VIEWPORT(vp), VIK_VIEWPORT_DRAWMODE_KH );
 411       else if ( stack->under == NULL && eq_pos == 4 && strncasecmp ( line, "mode", eq_pos ) == 0 && strcasecmp ( line+5, "mercator" ) == 0)
 412         vik_viewport_set_drawmode ( VIK_VIEWPORT(vp), VIK_VIEWPORT_DRAWMODE_MERCATOR );
 413       else if ( stack->under == NULL && eq_pos == 5 && strncasecmp ( line, "color", eq_pos ) == 0 )
 414         vik_viewport_set_background_color ( VIK_VIEWPORT(vp), line+6 );
 415       else if ( stack->under == NULL && eq_pos == 9 && strncasecmp ( line, "drawscale", eq_pos ) == 0 )
 416         vik_viewport_set_draw_scale ( VIK_VIEWPORT(vp), TEST_BOOLEAN(line+10) );
 417       else if ( stack->under == NULL && eq_pos == 14 && strncasecmp ( line, "drawcentermark", eq_pos ) == 0 )
 418         vik_viewport_set_draw_centermark ( VIK_VIEWPORT(vp), TEST_BOOLEAN(line+15) );
 419       else if ( stack->under && eq_pos == 4 && strncasecmp ( line, "name", eq_pos ) == 0 )
 420         vik_layer_rename ( VIK_LAYER(stack->data), line+5 );
 421       else if ( eq_pos == 7 && strncasecmp ( line, "visible", eq_pos ) == 0 )
 422         VIK_LAYER(stack->data)->visible = TEST_BOOLEAN(line+8);
 423       else if ( eq_pos != -1 && stack->under )
 424       {
 425         gboolean found_match = FALSE;
 426
 427         /* go thru layer params. if len == eq_pos && starts_with jazz, set it. */
 428         /* also got to check for name and visible. */
 429
 430         if ( ! params )
 431         {
 432           g_warning ( "Line %ld: No options for this kind of layer", line_num );
 433           continue;
 434         }
 435
 436         for ( i = 0; i < params_count; i++ )
 437           if ( strlen(params[i].name) == eq_pos && strncasecmp ( line, params[i].name, eq_pos ) == 0 )
 438           {
 439             VikLayerParamData x;
 440             line += eq_pos+1;
 441             if ( params[i].type == VIK_LAYER_PARAM_STRING_LIST ) {
 442               GList *l = g_list_append ( g_hash_table_lookup ( string_lists, (gpointer) ((gint) i) ), g_strdup(line) );
 443               g_hash_table_replace ( string_lists, (gpointer) ((gint)i), l );
 444               /* add the value to a list, possibly making a new list.
 445                * this will be passed to the layer when we read an ~EndLayer */
 446             } else {
 447               switch ( params[i].type )
 448               {
 449                 case VIK_LAYER_PARAM_DOUBLE: x.d = strtod(line, NULL); break;
 450                 case VIK_LAYER_PARAM_UINT: x.u = strtoul(line, NULL, 10); break;
 451                 case VIK_LAYER_PARAM_INT: x.i = strtol(line, NULL, 10); break;
 452                 case VIK_LAYER_PARAM_BOOLEAN: x.b = TEST_BOOLEAN(line); break;
 453                 case VIK_LAYER_PARAM_COLOR: memset(&(x.c), 0, sizeof(x.c)); /* default: black */
 454                                           gdk_color_parse ( line, &(x.c) ); break;
 455                 /* STRING or STRING_LIST -- if STRING_LIST, just set param to add a STRING */
 456                 default: x.s = line;
 457               }
 458               vik_layer_set_param ( VIK_LAYER(stack->data), i, x, vp );
 459             }
 460             found_match = TRUE;
 461             break;
 462           }
 463         if ( ! found_match )
 464           g_warning ( "Line %ld: Unknown parameter. Line:\n%s", line_num, line );
 465       }
 466       else
 467         g_warning ( "Line %ld: Invalid parameter or parameter outside of layer.", line_num );
 468     }
 469 /* could be:
 470 [Layer Type=Bla]
 471 [EndLayer]
 472 [LayerData]
 473 name=this
 474 #comment
 475 */
 476   }
 477
 478   while ( stack )
 479   {
 480     if ( stack->under && stack->under->data && stack->data )
 481     {
 482       vik_aggregate_layer_add_layer ( VIK_AGGREGATE_LAYER(stack->under->data), VIK_LAYER(stack->data) );
 483       vik_layer_post_read ( VIK_LAYER(stack->data), vp, TRUE );
 484     }
 485     pop(&stack);
 486   }
 487
 488   if ( ll.lat != 0.0 || ll.lon != 0.0 )
 489     vik_viewport_set_center_latlon ( VIK_VIEWPORT(vp), &ll );
 490
 491   if ( ( ! VIK_LAYER(top)->visible ) && VIK_LAYER(top)->realized )
 492     vik_treeview_item_set_visible ( VIK_LAYER(top)->vt, &(VIK_LAYER(top)->iter), FALSE );
 493
 494   /* delete anything we've forgotten about -- should only happen when file ends before an EndLayer */
 495   g_hash_table_foreach ( string_lists, string_list_delete, NULL );
 496   g_hash_table_destroy ( string_lists );
 497 }
 498
 499 /*
 500 read thru file
 501 if "[Layer Type="
 502   push(&stack)
 503   new default layer of type (str_to_type) (check interface->name)
 504 if "[EndLayer]"
 505   VikLayer *vl = stack->data;
 506   pop(&stack);
 507   vik_aggregate_layer_add_layer(stack->data, vl);
 508 if "[LayerData]"
 509   vik_layer_data ( VIK_LAYER_DATA(stack->data), f, vp );
 510
 511 */
 512
 513 /* ---------------------------------------------------- */
 514
 515 static FILE *xfopen ( const char *fn, const char *mode )
 516 {
 517   if ( strcmp(fn,"-") == 0 )
 518     return stdin;
 519   else
 520     return fopen(fn, "r");
 521 }
 522
 523 static void xfclose ( FILE *f )
 524 {
 525   if ( f != stdin && f != stdout )
 526     fclose ( f );
 527 }
 528
 529 /* 0 on failure, 1 on success (vik file) 2 on success (other file) */
 530 gshort a_file_load ( VikAggregateLayer *top, VikViewport *vp, const gchar *filename )
 531 {
 532   FILE *f = xfopen ( filename, "r" );
 533
 534   g_assert ( vp );
 535
 536   if ( ! f )
 537     return 0;
 538
 539   if ( check_magic ( f, VIK_MAGIC ) )
 540   {
 541     file_read ( top, f, vp );
 542     if ( f != stdin )
 543       xfclose(f);
 544     return 1;
 545   }
 546   else
 547   {
 548     VikCoord new_center;
 549     VikLayer *vtl = vik_layer_create ( VIK_LAYER_TRW, vp, NULL, FALSE );
 550     vik_layer_rename ( vtl, a_file_basename ( filename ) );
 551
 552     if ( check_magic ( f, GPX_MAGIC ) )
 553       a_gpx_read_file ( VIK_TRW_LAYER(vtl), f );
 554     else
 555      a_gpspoint_read_file ( VIK_TRW_LAYER(vtl), f );
 556
 557     vik_layer_post_read ( vtl, vp, TRUE );
 558
 559     vik_aggregate_layer_add_layer ( top, vtl );
 560
 561     if ( vik_trw_layer_find_center ( VIK_TRW_LAYER(vtl), &new_center ) )
 562       vik_viewport_set_center_coord ( VIK_VIEWPORT(vp), &new_center );
 563     xfclose(f);
 564     return 2;
 565   }
 566 }
 567
 568 gboolean a_file_save ( VikAggregateLayer *top, gpointer vp, const gchar *filename )
 569 {
 570   FILE *f = fopen(filename, "w");
 571
 572   if ( ! f )
 573     return FALSE;
 574
 575   file_write ( top, f, vp );
 576
 577   fclose(f);
 578
 579   return TRUE;
 580 }
 581
 582
 583 const gchar *a_file_basename ( const gchar *filename )
 584 {
 585   const gchar *t = filename + strlen(filename) - 1;
 586   while ( --t > filename )
 587     if ( *(t-1) == FILE_SEP )
 588       break;
 589   if ( t >= filename )
 590     return t;
 591   return filename;
 592 }
 593
 594 gboolean a_file_export ( VikTrwLayer *vtl, const gchar *filename, gshort file_type )
 595 {
 596   FILE *f = fopen ( filename, "w" );
 597   if ( f )
 598   {
 599     if ( file_type == FILE_TYPE_GPSMAPPER )
 600       a_gpsmapper_write_file ( vtl, f );
 601     else if ( file_type == FILE_TYPE_GPX )
 602       a_gpx_write_file ( vtl, f );
 603     else
 604       a_gpspoint_write_file ( vtl, f );
 605     fclose ( f );
 606     return TRUE;
 607   }
 608   return FALSE;
 609 }
 610
 611 const gchar *a_get_viking_dir()
 612 {
 613   static gchar *viking_dir = NULL;
 614
 615   if (!viking_dir) {
 616     const gchar *home = g_getenv("HOME");
 617     if (!home || access(home, W_OK))
 618       home = g_get_home_dir ();
 619 #ifdef HAVE_MKDTEMP
 620     if (!home || access(home, W_OK))
 621     {
 622       static gchar temp[] = {"/tmp/vikXXXXXX"};
 623       home = mkdtemp(temp);
 624     }
 625 #endif
 626     if (!home || access(home, W_OK))
 627       /* Fatal error */
 628       g_critical("Unable to find a base directory");
 629
 630     /* Build the name of the directory */
 631     viking_dir = g_build_filename(home, ".viking", NULL);
 632     if (access(viking_dir, F_OK))
 633       g_mkdir(viking_dir, 0755);
 634   }
 635
 636   return viking_dir;
 637 }