trunk/src/map-tool.c

/*
 * Copyright (C) 2008 Till Harbaum <till@harbaum.org>.
 *
 * This file is part of GPXView.
 *
 * GPXView 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GPXView 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 GPXView.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "gpxview.h"
#include <math.h>    // for isnan

#ifdef ENABLE_OSM_GPS_MAP
#include "osm-gps-map.h"
#endif

/* equatorial radius in meters */
#define EQ_RADIUS     (6378137.0)

#define RAD2DEG(a)  (((a)*180.0)/M_PI)
#define DEG2RAD(a)  (((a)*M_PI)/180.0)

typedef struct {
  appdata_t *appdata;
  GtkWidget *widget;
  GtkWidget *zoomin, *zoomout, *gps;
  gint handler_id;
  cache_t *press_on;
#if MAEMO_VERSION_MAJOR == 5
  GtkWidget *old_view;
#endif
} map_context_t;

#define PROXY_KEY  "/system/http_proxy/"

static const char *get_proxy_uri(appdata_t *appdata) {
  static char proxy_buffer[64] = "";
  
  /* use environment settings if preset */
  const char *proxy = g_getenv("http_proxy");
  if(proxy) {
    printf("http_proxy: %s\n", proxy);
    return proxy;
  }

  /* ------------- get proxy settings -------------------- */
  if(gconf_client_get_bool(appdata->gconf_client, 
                           PROXY_KEY "use_http_proxy", NULL)) {

    /* we can savely ignore things like "ignore_hosts" since we */
    /* are pretty sure not inside the net of one of our map renderers */
    /* (unless the user works at google :-) */
      
    /* get basic settings */
    char *host = 
      gconf_client_get_string(appdata->gconf_client, PROXY_KEY "host", NULL);
    if(host) {
      int port =
        gconf_client_get_int(appdata->gconf_client, PROXY_KEY "port", NULL);

      snprintf(proxy_buffer, sizeof(proxy_buffer),
               "http://%s:%u", host, port);

      g_free(host);
    }
    return proxy_buffer;
  }

  return NULL;
}

static void map_zoom(map_context_t *context, int step) {
  int zoom;
  OsmGpsMap *map = OSM_GPS_MAP(context->widget);
  g_object_get(map, "zoom", &zoom, NULL);
  zoom = osm_gps_map_set_zoom(map, zoom+step);

  /* enable/disable zoom buttons as required */
  gtk_widget_set_sensitive(context->zoomin, zoom<17);
  gtk_widget_set_sensitive(context->zoomout, zoom>1);
}

static gboolean
cb_map_zoomin(GtkButton *button, map_context_t *context) {
  map_zoom(context, +1);
  return FALSE;
}

static gboolean
cb_map_zoomout(GtkButton *button, map_context_t *context) {
  map_zoom(context, -1);
  return FALSE;
}

static gboolean
cb_map_gps(GtkButton *button, map_context_t *context) {
  pos_t *refpos = get_pos(context->appdata);
  if(refpos && !isnan(refpos->lat) && !isnan(refpos->lon)) {
    osm_gps_map_set_mapcenter(OSM_GPS_MAP(context->widget),
                              refpos->lat, refpos->lon, 14);     
  } else {
    /* no coordinates given: display the entire world */
    osm_gps_map_set_mapcenter(OSM_GPS_MAP(context->widget), 
                              0.0, 0.0, 1);
  }

  return FALSE;
}

static GtkWidget 
*map_add_button(const gchar *icon, GCallback cb, gpointer data, 
                char *tooltip) {
  GtkWidget *button = gtk_button_new();
  gtk_button_set_image(GTK_BUTTON(button), 
                       gtk_image_new_from_stock(icon, GTK_ICON_SIZE_BUTTON));
  g_signal_connect(button, "clicked", cb, data);
#ifndef USE_MAEMO
  gtk_widget_set_tooltip_text(button, tooltip);
#endif
  return button;
}

static gboolean map_gps_update(gpointer data) {
  map_context_t *context = (map_context_t*)data;

  pos_t *refpos = get_pos(context->appdata);
  gboolean ok = (refpos!= NULL) && !isnan(refpos->lat) && !isnan(refpos->lon);

  /* get reference position and go there */
  gtk_widget_set_sensitive(context->gps, ok);

  return TRUE;
}

static gboolean on_map_configure(GtkWidget *widget,
                                 GdkEventConfigure *event,
                                 map_context_t *context) {

  cb_map_gps(NULL, context);

  return FALSE;
}

static void map_draw_cachelist(GtkWidget *map, cache_t *cache) {
  while(cache) {
    GdkPixbuf *icon = icon_get(ICON_CACHE_TYPE, cache->type);
    
    osm_gps_map_add_image(OSM_GPS_MAP(map), 
                          cache->pos.lat, cache->pos.lon, icon);

    cache = cache->next;
  }
}

/* draw a nice popup */
typedef struct {
  appdata_t *appdata;
  GtkWidget *window;
  GMainLoop *loop;
} popup_context_t;

/* draw shape */
#define ARROW_BORDER   20
#define CORNER_RADIUS  10

#ifndef USE_MAEMO
#define POPUP_WIDTH  300
#define POPUP_HEIGHT 100
#else
#define POPUP_WIDTH  350
#define POPUP_HEIGHT 120
#endif

static gboolean
pointer_in_window(GtkWidget *widget, gint x_root, gint y_root) {
  if(GTK_WIDGET_MAPPED(gtk_widget_get_toplevel(widget))) {
    gint window_x, window_y;
    
    gdk_window_get_position(gtk_widget_get_toplevel(widget)->window, 
                            &window_x, &window_y);
    
    if(x_root >= window_x && x_root < window_x + widget->allocation.width &&
        y_root >= window_y && y_root < window_y + widget->allocation.height)
      return TRUE;
  }
  
  return FALSE;
}

static gboolean
on_button_press_event(GtkWidget *widget, 
                          GdkEventButton *event, popup_context_t *context) {
  gboolean in = pointer_in_window(widget, event->x_root, event->y_root);

  printf("overlay button press (in = %d)\n", in);
  return !in;
}

static gboolean
on_button_release_event(GtkWidget *widget, 
                          GdkEventButton *event, popup_context_t *context) {
  gboolean in = pointer_in_window(widget, event->x_root, event->y_root);

  printf("overlay button release (in = %d)\n", in);

  if(!in) {
    printf("destroying popup\n");
    gtk_widget_destroy(gtk_widget_get_toplevel(widget));
  }

  return !in;
}

static void
shutdown_loop(popup_context_t *context) {
  if(g_main_loop_is_running(context->loop))
    g_main_loop_quit(context->loop);
}

static gint
run_delete_handler(GtkWindow *window, GdkEventAny *event,
                   popup_context_t *context) {
  shutdown_loop(context);
  return TRUE; /* Do not destroy */
}

static void
run_destroy_handler(GtkWindow *window, popup_context_t *context) {
  /* shutdown_loop will be called by run_unmap_handler */
  printf("popup destroyed\n");
}

static void
run_unmap_handler(GtkWindow *window, popup_context_t *context) {
  shutdown_loop(context);
}

static void popup_window_shape(GtkWidget *window, int tip_x, int tip_y) {
  GdkBitmap *mask = gdk_pixmap_new(NULL, POPUP_WIDTH, POPUP_HEIGHT, 1);

  GdkGC *gc = gdk_gc_new(mask);
  GdkColormap *colormap;
  GdkColor black;
  GdkColor white;

  /* get black/white color values */
  colormap = gdk_colormap_get_system();
  gdk_color_black(colormap, &black);
  gdk_color_white(colormap, &white);

  /* erase */
  gdk_gc_set_foreground(gc, &black);
  gdk_gc_set_background(gc, &white);

  /* erase background */
  gdk_draw_rectangle(mask, gc, TRUE, 0, 0, POPUP_WIDTH, POPUP_HEIGHT);

  gdk_gc_set_foreground(gc, &white);
  gdk_gc_set_background(gc, &black);

  /* the tip is always above or below the "bubble" but never at its side */
  guint tip_offset = (tip_y == 0)?ARROW_BORDER:0;

  gdk_draw_rectangle(mask, gc, TRUE, 
                     0, tip_offset + CORNER_RADIUS, 
                     POPUP_WIDTH, 
                     POPUP_HEIGHT - 2*CORNER_RADIUS - ARROW_BORDER);

  gdk_draw_rectangle(mask, gc, TRUE, 
                     CORNER_RADIUS, tip_offset,
                     POPUP_WIDTH  - 2*CORNER_RADIUS, 
                     POPUP_HEIGHT - ARROW_BORDER);
  
  int off[][2] = { 
          { CORNER_RADIUS,               tip_offset + CORNER_RADIUS },
          { POPUP_WIDTH - CORNER_RADIUS, tip_offset + CORNER_RADIUS },
          { POPUP_WIDTH - CORNER_RADIUS, 
            POPUP_HEIGHT - CORNER_RADIUS - ARROW_BORDER + tip_offset},
          { CORNER_RADIUS,
            POPUP_HEIGHT - CORNER_RADIUS  - ARROW_BORDER + tip_offset}};

  int i;
  for(i=0;i<4;i++) {
    gdk_draw_arc(mask, gc, TRUE,
                 off[i][0]-CORNER_RADIUS, off[i][1]-CORNER_RADIUS,
                 2*CORNER_RADIUS,         2*CORNER_RADIUS,
                 0, 360*64);
  }

  GdkPoint points[3] = { {POPUP_WIDTH*1/3, POPUP_HEIGHT/2}, 
                         {POPUP_WIDTH*2/3, POPUP_HEIGHT/2}, 
                         {tip_x,tip_y} };
  gdk_draw_polygon(mask, gc, TRUE, points, 3);


  gdk_window_shape_combine_mask(window->window, mask, 0, 0);
}

/* create a left aligned label (normal ones are centered) */
static GtkWidget *gtk_label_left_new(char *str) {
  GtkWidget *label = gtk_label_new(str);
  gtk_misc_set_alignment(GTK_MISC(label), 0.f, .5f);
  return label;
}

/* the small labels are actually only on maemo small */
#ifdef USE_MAEMO
#define MARKUP_SMALL "<span size='small'>%s</span>"
GtkWidget *gtk_label_small_left_new(char *str) {
  GtkWidget *label = gtk_label_new("");
  char *markup = g_markup_printf_escaped(MARKUP_SMALL, str);
  gtk_label_set_markup(GTK_LABEL(label), markup);
  g_free(markup);
  gtk_misc_set_alignment(GTK_MISC(label), 0.f, .5f);
  return label;
}
#define gtk_label_big_left_new(a) gtk_label_left_new(a)
#else
#define gtk_label_small_left_new(a) gtk_label_left_new(a)
#define MARKUP_BIG "<span size='x-large'>%s</span>"
GtkWidget *gtk_label_big_left_new(char *str) {
  GtkWidget *label = gtk_label_new("");
  char *markup = g_markup_printf_escaped(MARKUP_BIG, str);
  gtk_label_set_markup(GTK_LABEL(label), markup);
  g_free(markup);
  gtk_misc_set_alignment(GTK_MISC(label), 0.f, .5f);
  return label;
}
#endif

void cache_popup(map_context_t *mcontext, cache_t *cache) {
  popup_context_t pcontext;
  pcontext.appdata = mcontext->appdata;

  pcontext.window = gtk_window_new(GTK_WINDOW_POPUP);
  gtk_widget_realize(pcontext.window);
  gtk_window_set_default_size(GTK_WINDOW(pcontext.window), 
                              POPUP_WIDTH, POPUP_HEIGHT); 
  gtk_window_resize(GTK_WINDOW(pcontext.window), POPUP_WIDTH, POPUP_HEIGHT); 
  //  gtk_window_set_resizable(GTK_WINDOW(pcontext.window), FALSE);
  gtk_window_set_transient_for(GTK_WINDOW(pcontext.window), 
                               GTK_WINDOW(mcontext->appdata->window));
  gtk_window_set_keep_above(GTK_WINDOW(pcontext.window), TRUE);    
  gtk_window_set_destroy_with_parent(GTK_WINDOW(pcontext.window), TRUE);
  gtk_window_set_gravity(GTK_WINDOW(pcontext.window), GDK_GRAVITY_STATIC);
  gtk_window_set_modal(GTK_WINDOW(pcontext.window), TRUE);

  /* connect events */
  g_signal_connect(G_OBJECT(pcontext.window), "button-press-event",
                   G_CALLBACK(on_button_press_event), &pcontext);
  g_signal_connect(G_OBJECT(pcontext.window), "button-release-event",
                   G_CALLBACK(on_button_release_event), &pcontext);
  g_signal_connect(G_OBJECT(pcontext.window), "delete-event",
                   G_CALLBACK(run_delete_handler), &pcontext);
  g_signal_connect(G_OBJECT(pcontext.window), "destroy",
                   G_CALLBACK(run_destroy_handler), &pcontext);
  g_signal_connect(G_OBJECT(pcontext.window), "unmap",
                   G_CALLBACK(run_unmap_handler), &pcontext);
  
  gdk_pointer_grab(pcontext.window->window, TRUE,
     GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | GDK_BUTTON_MOTION_MASK,
                   NULL, NULL, GDK_CURRENT_TIME);
  gtk_grab_add(pcontext.window);

  /* check whether cache is in upper or lower half of window */
  gint x, y, sx, sy;
  osm_gps_map_geographic_to_screen(OSM_GPS_MAP(mcontext->widget),
                                   cache->pos.lat, cache->pos.lon,
                                   &sx, &sy);
  
  gdk_window_get_origin(mcontext->widget->window, &x, &y);

  gint ax = 0, ay = 0; 
  if(sx > mcontext->widget->allocation.width/2)
    ax = POPUP_WIDTH;

  if(sy > mcontext->widget->allocation.height/2)
    ay = POPUP_HEIGHT;

#if !defined(USE_MAEMO) || (MAEMO_VERSION_MAJOR < 5)
  GdkColor color;
  gdk_color_parse("darkgray", &color);
  gtk_widget_modify_bg(GTK_WIDGET(pcontext.window), GTK_STATE_NORMAL, &color);
#endif

  gtk_window_move(GTK_WINDOW(pcontext.window),
                  x + mcontext->widget->allocation.x + sx - ax, 
                  y + mcontext->widget->allocation.y + sy - ay); 


  GtkWidget *alignment = gtk_alignment_new(0.5, 0.5, 1.0, 1.0);
  gtk_alignment_set_padding(GTK_ALIGNMENT(alignment),
                            CORNER_RADIUS/2 + (ay?0:ARROW_BORDER), 
                            CORNER_RADIUS/2 + (ay?ARROW_BORDER:0),
                            CORNER_RADIUS, CORNER_RADIUS);

  /* --- actual content ---- */
  GtkWidget *vbox = gtk_vbox_new(FALSE, 0);

  if(cache->id) {
    GtkWidget *ihbox = gtk_hbox_new(FALSE, 0);

    gtk_box_pack_start(GTK_BOX(ihbox), 
       icon_get_widget(ICON_CACHE_TYPE, cache->type),
       FALSE, FALSE, 5);

    gtk_box_pack_start_defaults(GTK_BOX(ihbox), 
                gtk_label_big_left_new(cache->id));

    gtk_box_pack_start_defaults(GTK_BOX(vbox), ihbox);
  }

  if(cache->name) {
    GtkWidget *label = gtk_label_small_left_new(cache->name);
    gtk_label_set_ellipsize(GTK_LABEL(label), PANGO_ELLIPSIZE_END);
    gtk_box_pack_start_defaults(GTK_BOX(vbox), label);
  }

  GtkWidget *hbox = gtk_hbox_new(FALSE, 0);
  if(cache->terrain) {
    GtkWidget *ihbox = gtk_hbox_new(FALSE, 0);
    gtk_box_pack_start(GTK_BOX(ihbox),
       gtk_label_small_left_new(_("Terrain:")), FALSE, FALSE, 0);
    gtk_box_pack_start(GTK_BOX(ihbox), 
       icon_get_widget(ICON_STARS, (int)(cache->terrain*2-2)),
       FALSE, FALSE, 5);
    gtk_box_pack_start_defaults(GTK_BOX(hbox), ihbox);
  }

  if(cache->difficulty) {
    GtkWidget *ihbox = gtk_hbox_new(FALSE, 0);
    gtk_box_pack_start(GTK_BOX(ihbox),
       gtk_label_small_left_new(_("Difficulty:")), FALSE, FALSE, 0);
    gtk_box_pack_start(GTK_BOX(ihbox), 
       icon_get_widget(ICON_STARS, (int)(cache->difficulty*2-2)),
       FALSE, FALSE, 5);
    gtk_box_pack_start_defaults(GTK_BOX(hbox), ihbox);
  }

  gtk_box_pack_start(GTK_BOX(vbox), hbox, FALSE, FALSE, 0);

  gtk_container_add(GTK_CONTAINER(alignment), vbox);
  /* ----------------------- */


  gtk_container_add(GTK_CONTAINER(pcontext.window), alignment);
  
  /* give window its shape */
  popup_window_shape(pcontext.window, ax, ay);

  gtk_widget_show_all(pcontext.window);

  /* handle this popup until it's gone */
  
  pcontext.loop = g_main_loop_new(NULL, FALSE);

  GDK_THREADS_LEAVE();  
  g_main_loop_run(pcontext.loop);
  GDK_THREADS_ENTER();  

  g_main_loop_unref(pcontext.loop);

  printf("cache popup removed\n");
}

static void
map_cachelist_nearest(cache_t *cache, pos_t *pos, 
                      cache_t **result, float *distance) {
  while(cache) {
    float dist = 
      pow(cache->pos.lat - pos->lat, 2) + 
      pow(cache->pos.lon - pos->lon, 2);

    if(!(dist > *distance)) {
      *result = cache;
      *distance = dist;
    }

    cache = cache->next;
  }
}

static cache_t *map_closest(map_context_t *context, pos_t *pos) {
  cache_t *result = NULL;
  float distance = NAN;
  
#ifdef USE_MAEMO
  if(!context->appdata->cur_gpx) {
#endif
    /* search all geocaches */
    gpx_t *gpx = context->appdata->gpx;
    while(gpx) {
      map_cachelist_nearest(gpx->cache, pos, &result, &distance);
      gpx = gpx->next;
    }
#ifdef USE_MAEMO
  } else {
    map_cachelist_nearest(context->appdata->cur_gpx->cache, 
                          pos, &result, &distance);
  }
#endif

  return result;
}

/* translate between osm-gps-map positions and gpxview ones */
pos_t coord2pos(coord_t coo) {
  pos_t pos;
  pos.lat = RAD2DEG(coo.rlat);
  pos.lon = RAD2DEG(coo.rlon);
  return pos;
}

static int dist2pixel(map_context_t *context, float km, float lat) {
  int zoom;
  g_object_get(OSM_GPS_MAP(context->widget), "zoom", &zoom, NULL);

  /* world at zoom 1 == 512 pixels */
  float m_per_pix = 
    cos(DEG2RAD(lat))*2*M_PI*EQ_RADIUS/(1<<(8+zoom));

  return 1000.0*km/m_per_pix;
}

#define CLICK_FUZZ (24)

static gboolean
on_map_button_press_event(GtkWidget *widget, 
                            GdkEventButton *event, map_context_t *context) {
  OsmGpsMap *map = OSM_GPS_MAP(context->widget);

  /* got a press event without release event? eat it! */
  if(context->press_on != NULL) {
    printf("PRESS: already\n");
    return TRUE;
  }

  pos_t pos = 
    coord2pos(osm_gps_map_get_co_ordinates(map, event->x, event->y));

  cache_t *nearest = map_closest(context, &pos);  
  if(nearest) {
    float dist = gpx_pos_get_distance(pos, nearest->pos, FALSE);
    if(dist2pixel(context, dist, nearest->pos.lat) < CLICK_FUZZ) 
      context->press_on = nearest;
  }
  
  return FALSE;
}

static gboolean
on_map_button_release_event(GtkWidget *widget, 
                            GdkEventButton *event, map_context_t *context) {
  if(context->press_on) {
    OsmGpsMap *map = OSM_GPS_MAP(context->widget);

    pos_t pos = 
      coord2pos(osm_gps_map_get_co_ordinates(map, event->x, event->y));

    cache_t *nearest = map_closest(context, &pos);  
    if(nearest && nearest == context->press_on) {
      float dist = gpx_pos_get_distance(pos, nearest->pos, FALSE);
      if(dist2pixel(context, dist, nearest->pos.lat) < CLICK_FUZZ)
        cache_popup(context, nearest);
    }
    context->press_on = NULL;
  }

  return FALSE;
}


#if MAEMO_VERSION_MAJOR == 5
static void on_window_destroy(GtkWidget *widget, map_context_t *context) {
  printf("destroy map view\n");

  /* restore cur_view */
  context->appdata->cur_view = context->old_view;

  gtk_timeout_remove(context->handler_id);
  g_free(context);
}
#endif

void map(appdata_t *appdata) {
  map_context_t *context = g_new0(map_context_t, 1);
  context->appdata = appdata;

  GtkWidget *hbox = gtk_hbox_new(FALSE, 0);

  char *path = g_strdup_printf("%s/map/", appdata->image_path);
  const char *proxy = get_proxy_uri(appdata);

  context->widget = g_object_new(OSM_TYPE_GPS_MAP,
                "repo-uri", MAP_SOURCE_OPENSTREETMAP,
                "tile-cache", path,
                proxy?"proxy-uri":NULL, proxy,
                 NULL);

  g_free(path);

  char *name = NULL;
#ifdef USE_MAEMO
  if(!appdata->cur_gpx) {
#endif
    /* draw all geocaches */
    gpx_t *gpx = appdata->gpx;
    while(gpx) {
      map_draw_cachelist(context->widget, gpx->cache);
      gpx = gpx->next;
    }
    name = g_strdup(_("all geocaches"));
#ifdef USE_MAEMO
  } else {
    map_draw_cachelist(context->widget, appdata->cur_gpx->cache);
    name = g_strdup(appdata->cur_gpx->name);
  }
#endif

  char *title = g_strdup_printf(_("Map - %s"), name);
  g_free(name);

#if MAEMO_VERSION_MAJOR == 5
  GtkWidget *window = hildon_stackable_window_new();
  gtk_window_set_title(GTK_WINDOW(window), title);
#else
  GtkWidget *dialog = gtk_dialog_new_with_buttons(title,
                          GTK_WINDOW(appdata->window),
                          GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT,
                          GTK_STOCK_CLOSE, GTK_RESPONSE_CLOSE,
                          NULL);

#ifndef USE_MAEMO
  gtk_window_set_default_size(GTK_WINDOW(dialog), 640, 480);
#else
  gtk_window_set_default_size(GTK_WINDOW(dialog), 800, 480);
#endif
#endif

  g_free(title);

  g_signal_connect(G_OBJECT(context->widget), "configure-event",
                   G_CALLBACK(on_map_configure), context);

  g_signal_connect(G_OBJECT(context->widget), "button-press-event",
                   G_CALLBACK(on_map_button_press_event), context);

  g_signal_connect(G_OBJECT(context->widget), "button-release-event",
                   G_CALLBACK(on_map_button_release_event), context);

  gtk_box_pack_start_defaults(GTK_BOX(hbox), context->widget);
  /* zoom button box */
  GtkWidget *vbox = gtk_vbox_new(FALSE,0);

  context->zoomin = 
    map_add_button(GTK_STOCK_ZOOM_IN, G_CALLBACK(cb_map_zoomin),
                   context, _("Zoom in"));
  gtk_box_pack_start(GTK_BOX(vbox), context->zoomin, FALSE, FALSE, 0);

  context->zoomout = 
    map_add_button(GTK_STOCK_ZOOM_OUT, G_CALLBACK(cb_map_zoomout),
                   context, _("Zoom out"));
  gtk_box_pack_start(GTK_BOX(vbox), context->zoomout, FALSE, FALSE, 0);

  context->gps = 
    map_add_button(GTK_STOCK_HOME, G_CALLBACK(cb_map_gps),
                   context, _("Jump to GPS position"));
  gtk_widget_set_sensitive(context->gps, FALSE);
  /* install handler for timed updates of the gps button */
  context->handler_id = gtk_timeout_add(1000, map_gps_update, context);
  gtk_box_pack_start(GTK_BOX(vbox), context->gps, FALSE, FALSE, 0);

  gtk_box_pack_start(GTK_BOX(hbox), vbox, FALSE, FALSE, 0);

#if MAEMO_VERSION_MAJOR == 5
  /* prevent some of the main screen things */
  context->old_view = appdata->cur_view;
  appdata->cur_view = NULL;

  g_signal_connect(G_OBJECT(window), "destroy", 
                   G_CALLBACK(on_window_destroy), context);

  gtk_container_add(GTK_CONTAINER(window), hbox); 
  gtk_widget_show_all(GTK_WIDGET(window));
 
#else
  gtk_box_pack_start_defaults(GTK_BOX(GTK_DIALOG(dialog)->vbox), hbox);
  gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_CLOSE);
  gtk_widget_show_all(dialog);
  gtk_dialog_run(GTK_DIALOG(dialog));
  gtk_timeout_remove(context->handler_id);
  gtk_widget_destroy(dialog);
  g_free(context);
#endif
}