## OsmGpsMap OsmGpsMap — The map display widget |

## Stability Level

Stable, unless otherwise indicated

## Functions

gchar * | osm_gps_map_get_default_cache_directory ()
const char * | osm_gps_map_source_get_friendly_name ()
const char * | osm_gps_map_source_get_repo_uri ()
const char * | osm_gps_map_source_get_image_format ()
int | osm_gps_map_source_get_min_zoom ()
int | osm_gps_map_source_get_max_zoom ()
gboolean | osm_gps_map_source_is_valid ()
GtkWidget * | osm_gps_map_new ()
void | osm_gps_map_download_maps ()
void | osm_gps_map_download_cancel_all ()
void | osm_gps_map_get_bbox ()
void | osm_gps_map_set_center ()
void | osm_gps_map_set_center_and_zoom ()
int | osm_gps_map_set_zoom ()
int | osm_gps_map_zoom_in ()
int | osm_gps_map_zoom_out ()
void | osm_gps_map_scroll ()
float | osm_gps_map_get_scale ()
void | osm_gps_map_set_keyboard_shortcut ()
OsmGpsMapPoint * | osm_gps_map_get_event_location ()
void | osm_gps_map_convert_geographic_to_screen ()
void | osm_gps_map_convert_screen_to_geographic ()
void | osm_gps_map_gps_add ()
void | osm_gps_map_gps_clear ()
OsmGpsMapTrack * | osm_gps_map_gps_get_track ()
void | osm_gps_map_track_add ()
gboolean | osm_gps_map_track_remove ()
void | osm_gps_map_track_remove_all ()
OsmGpsMapImage * | osm_gps_map_image_add ()
OsmGpsMapImage * | osm_gps_map_image_add_with_alignment ()
gboolean | osm_gps_map_image_remove ()
void | osm_gps_map_image_remove_all ()
void | osm_gps_map_layer_add ()
gboolean | osm_gps_map_layer_remove ()
void | osm_gps_map_layer_remove_all ()

## Properties

gboolean | auto-center | Read / Write / Construct
gfloat | auto-center-threshold | Read / Write / Construct
gboolean | auto-download | Read / Write / Construct
gint | drag-limit | Read / Write / Construct Only
gint | gps-track-highlight-radius | Read / Write / Construct
gint | gps-track-point-radius | Read / Write / Construct
gfloat | gps-track-width | Read / Write / Construct
gchar * | image-format | Read / Write / Construct Only
gfloat | latitude | Read
gfloat | longitude | Read
gint | map-source | Read / Write / Construct
gint | map-x | Read / Write / Construct Only
gint | map-y | Read / Write / Construct Only
gint | max-zoom | Read / Write / Construct Only
gint | min-zoom | Read / Write / Construct Only
gchar * | proxy-uri | Read / Write / Construct Only
gboolean | record-trip-history | Read / Write / Construct
gchar * | repo-uri | Read / Write / Construct Only
gboolean | show-gps-point | Read / Write / Construct
gboolean | show-trip-history | Read / Write / Construct
gchar * | tile-cache | Read / Write / Construct
gchar * | tile-cache-base | Read / Write / Construct Only
gint | tile-zoom-offset | Read / Write / Construct Only
gint | tiles-queued | Read
gint | zoom | Read / Write / Construct Only

## Signals

void | changed | Run First

## Types and Values

struct | OsmGpsMap
struct | OsmGpsMapClass
#define | OSM_GPS_MAP_INVALID
#define | OSM_GPS_MAP_CACHE_DISABLED
#define | OSM_GPS_MAP_CACHE_AUTO
#define | OSM_GPS_MAP_CACHE_FRIENDLY
enum | OsmGpsMapSource_t
enum | OsmGpsMapKey_t

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GtkWidget
                ╰── GtkDrawingArea
                    ╰── OsmGpsMap

## Implemented Interfaces

OsmGpsMap implements AtkImplementorIface and GtkBuildable.

## Includes

    #include <osm-gps-map.h>

## Description

OsmGpsMap is a widget for displaying a map, optionally overlaid with a track(s) of GPS co-ordinates, images, points of interest or on screen display controls. OsmGpsMap downloads (and caches for offline use) map data from a number of websites, including

OpenStreetMap

Example 1. Showing a map

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    int main (int argc, char **argv)
    {
        g_thread_init(NULL);
        gtk_init (&argc, &argv);

        GtkWidget *map = osm_gps_map_new ();
        GtkWidget *w = gtk_window_new (GTK_WINDOW_TOPLEVEL);
        gtk_container_add (GTK_CONTAINER(w), map);
        gtk_widget_show_all (w);

        gtk_main ();
        return 0;
    }

OsmGpsMap allows great flexibility in customizing how the map tiles are cached, see “tile-cache-base” and “tile-cache” for more information.

A number of different map sources are supported, see OsmGpsMapSource_t. The default source, `OSM_GPS_MAP_SOURCE_OPENSTREETMAP` always works. Other sources, particular those from proprietary providers may work occasionally, and then cease to work. To check if a source is supported for the given version of this library, call `osm_gps_map_source_is_valid()`.

Example 2. Map with custom source and cache dir

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    int main (int argc, char **argv)
    {
        g_thread_init(NULL);
        gtk_init (&argc, &argv);
        OsmGpsMapSource_t source = OSM_GPS_MAP_SOURCE_VIRTUAL_EARTH_SATELLITE;

        if ( !osm_gps_map_source_is_valid(source) )
            return 1;

        GtkWidget *map = g_object_new (OSM_TYPE_GPS_MAP,
                         "map-source", source,
                         "tile-cache", "/tmp/",
                          NULL);
        GtkWidget *w = gtk_window_new (GTK_WINDOW_TOPLEVEL);
        gtk_container_add (GTK_CONTAINER(w), map);
        gtk_widget_show_all (w);

        gtk_main ();
        return 0;
    }

Finally, if you wish to use a custom map source not supported by OsmGpsMap, such as a custom map created with

CloudMade

then you can also pass a specially formatted string to “repo-uri”.

Example 3. Map using custom CloudMade map and on screen display

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    int main (int argc, char **argv)
    {
        g_thread_init(NULL);
        gtk_init (&argc, &argv);
        const gchar *cloudmate = "http://a.tile.cloudmade.com/YOUR_API_KEY/1/256/#Z/#X/#Y.png";

        GtkWidget *map = g_object_new (OSM_TYPE_GPS_MAP,
                         "repo-uri", cloudmate,
                          NULL);
        OsmGpsMapOsd *osd = osm_gps_map_osd_new ();
        GtkWidget *w = gtk_window_new (GTK_WINDOW_TOPLEVEL);
        osm_gps_map_layer_add (OSM_GPS_MAP(map), OSM_GPS_MAP_LAYER(osd));
        gtk_container_add (GTK_CONTAINER(w), map);
        gtk_widget_show_all (w);

        gtk_main ();
        return 0;
    }

## Functions

### osm_gps_map_get_default_cache_directory ()

    gchar *
    osm_gps_map_get_default_cache_directory
                                   (void);

#### Returns

the default cache directory for the library, that is the base directory to which the full cache path is appended. If “tile-cache-base” is omitted from the constructor then this value is used.

### osm_gps_map_source_get_friendly_name ()

    const char *
    osm_gps_map_source_get_friendly_name (OsmGpsMapSource_t source);

### osm_gps_map_source_get_repo_uri ()

    const char *
    osm_gps_map_source_get_repo_uri (OsmGpsMapSource_t source);

### osm_gps_map_source_get_image_format ()

    const char *
    osm_gps_map_source_get_image_format (OsmGpsMapSource_t source);

### osm_gps_map_source_get_min_zoom ()

    int
    osm_gps_map_source_get_min_zoom (OsmGpsMapSource_t source);

### osm_gps_map_source_get_max_zoom ()

    int
    osm_gps_map_source_get_max_zoom (OsmGpsMapSource_t source);

### osm_gps_map_source_is_valid ()

    gboolean
    osm_gps_map_source_is_valid (OsmGpsMapSource_t source);

### osm_gps_map_new ()

    GtkWidget *
    osm_gps_map_new (void);

Returns a new OsmGpsMap object, defaults to showing data from

OpenStreetMap

See the properties description for more information about construction parameters than could be passed to `g_object_new()`

#### Returns

a newly created OsmGpsMap object.

### osm_gps_map_download_maps ()

    void
    osm_gps_map_download_maps (OsmGpsMap *map,
                               OsmGpsMapPoint *pt1,
                               OsmGpsMapPoint *pt2,
                               int zoom_start,
                               int zoom_end);

Downloads all tiles over the supplied zoom range in the rectangular region specified by pt1 (north west corner) to pt2 (south east corner)

### osm_gps_map_download_cancel_all ()

    void
    osm_gps_map_download_cancel_all (OsmGpsMap *map);

Cancels all tiles currently being downloaded. Typically used if you wish to cacel a large number of tiles queued using `osm_gps_map_download_maps()`

Since: 0.7.0

### osm_gps_map_get_bbox ()

    void
    osm_gps_map_get_bbox (OsmGpsMap *map,
                          OsmGpsMapPoint *pt1,
                          OsmGpsMapPoint *pt2);

Returns the geographic locations of the bounding box describing the contents of the current window, i.e the top left and bottom right corners.

#### Parameters

pt1 | point to be filled with the top left location. | [out]
pt2 | point to be filled with the bottom right location. | [out]

### osm_gps_map_set_center ()

    void
    osm_gps_map_set_center (OsmGpsMap *map,
                            float latitude,
                            float longitude);

### osm_gps_map_set_center_and_zoom ()

    void
    osm_gps_map_set_center_and_zoom (OsmGpsMap *map,
                                     float latitude,
                                     float longitude,
                                     int zoom);

Since: 0.7.0

### osm_gps_map_set_zoom ()

    int
    osm_gps_map_set_zoom (OsmGpsMap *map,
                          int zoom);

### osm_gps_map_zoom_in ()

    int
    osm_gps_map_zoom_in (OsmGpsMap *map);

### osm_gps_map_zoom_out ()

    int
    osm_gps_map_zoom_out (OsmGpsMap *map);

### osm_gps_map_scroll ()

    void
    osm_gps_map_scroll (OsmGpsMap *map,
                        gint dx,
                        gint dy);

Scrolls the map by `dx` , `dy` pixels (positive north, east)

### osm_gps_map_get_scale ()

    float
    osm_gps_map_get_scale (OsmGpsMap *map);

#### Returns

the scale of the map at the center, in meters/pixel.

### osm_gps_map_set_keyboard_shortcut ()

    void
    osm_gps_map_set_keyboard_shortcut (OsmGpsMap *map,
                                       OsmGpsMapKey_t key,
                                       guint keyval);

Associates a keyboard shortcut with the supplied `keyval` (as returned by gdk_keyval_from_name or simiar). The action given in `key` will be triggered when the corresponding `keyval` is pressed. By default no keyboard shortcuts are associated.

#### Parameters

key | a OsmGpsMapKey_t |

### osm_gps_map_get_event_location ()

    OsmGpsMapPoint *
    osm_gps_map_get_event_location (OsmGpsMap *map,
                                    GdkEventButton *event);

A convenience function for getting the geographic location of events, such as mouse clicks, on the map

#### Parameters

event | A GtkEventButton that occured on the map |

#### Returns

The point on the globe corresponding to the click.

[transfer full]

Since: 0.7.0

### osm_gps_map_convert_geographic_to_screen ()

    void
    osm_gps_map_convert_geographic_to_screen
                                   (OsmGpsMap *map,
                                    OsmGpsMapPoint *pt,
                                    gint *pixel_x,
                                    gint *pixel_y);

Convert the given location on the globe to the corresponding pixel locations on the map.

#### Parameters

pt | location |
pixel_x | pixel location on map, x axis. | [out]
pixel_y | pixel location on map, y axis. | [out]

Since: 0.7.0

### osm_gps_map_convert_screen_to_geographic ()

    void
    osm_gps_map_convert_screen_to_geographic
                                   (OsmGpsMap *map,
                                    gint pixel_x,
                                    gint pixel_y,
                                    OsmGpsMapPoint *pt);

Convert the given pixel location on the map into corresponding location on the globe

#### Parameters

pixel_x | pixel location on map, x axis |
pixel_y | pixel location on map, y axis |
pt | location. | [out]

Since: 0.7.0

### osm_gps_map_gps_add ()

    void
    osm_gps_map_gps_add (OsmGpsMap *map,
                         float latitude,
                         float longitude,
                         float heading);

#### Parameters

latitude | degrees |
longitude | degrees |
heading | degrees or OSM_GPS_MAP_INVALID to disable showing heading |

Since: 0.7.0

### osm_gps_map_gps_clear ()

    void
    osm_gps_map_gps_clear (OsmGpsMap *map);

Since: 0.7.0

### osm_gps_map_gps_get_track ()

    OsmGpsMapTrack *
    osm_gps_map_gps_get_track (OsmGpsMap *map);

#### Returns

The OsmGpsMapTrack of the internal GPS track, i.e. that which is modified when calling `osm_gps_map_gps_add()`. You must not free this.

[transfer none]

Since: 0.7.0

### osm_gps_map_track_add ()

    void
    osm_gps_map_track_add (OsmGpsMap *map,
                           OsmGpsMapTrack *track);

Since: 0.7.0

### osm_gps_map_track_remove ()

    gboolean
    osm_gps_map_track_remove (OsmGpsMap *map,
                              OsmGpsMapTrack *track);

Since: 0.7.0

### osm_gps_map_track_remove_all ()

    void
    osm_gps_map_track_remove_all (OsmGpsMap *map);

Since: 0.7.0

### osm_gps_map_image_add ()

    OsmGpsMapImage *
    osm_gps_map_image_add (OsmGpsMap *map,
                           float latitude,
                           float longitude,
                           GdkPixbuf *image);

#### Returns

A OsmGpsMapImage representing the added pixbuf.

[transfer full]

Since: 0.7.0

### osm_gps_map_image_add_with_alignment ()

    OsmGpsMapImage *
    osm_gps_map_image_add_with_alignment (OsmGpsMap *map,
                                          float latitude,
                                          float longitude,
                                          GdkPixbuf *image,
                                          float xalign,
                                          float yalign);

#### Returns

A OsmGpsMapImage representing the added pixbuf.

[transfer full]

Since: 0.7.0

### osm_gps_map_image_remove ()

    gboolean
    osm_gps_map_image_remove (OsmGpsMap *map,
                              OsmGpsMapImage *image);

Since: 0.7.0

### osm_gps_map_image_remove_all ()

    void
    osm_gps_map_image_remove_all (OsmGpsMap *map);

Since: 0.7.0

### osm_gps_map_layer_add ()

    void
    osm_gps_map_layer_add (OsmGpsMap *map,
                           OsmGpsMapLayer *layer);

#### Parameters

layer | a OsmGpsMapLayer object |

Since: 0.7.0

### osm_gps_map_layer_remove ()

    gboolean
    osm_gps_map_layer_remove (OsmGpsMap *map,
                              OsmGpsMapLayer *layer);

#### Parameters

layer | a OsmGpsMapLayer object |

Since: 0.7.0

### osm_gps_map_layer_remove_all ()

    void
    osm_gps_map_layer_remove_all (OsmGpsMap *map);

Since: 0.7.0

## Types and Values

### struct OsmGpsMap

    struct OsmGpsMap;

### struct OsmGpsMapClass

    struct OsmGpsMapClass {
        GtkDrawingAreaClass parent_class;

        void (*draw_gps_point) (OsmGpsMap *map, cairo_t *cr);
    };

### OSM_GPS_MAP_INVALID

    #define OSM_GPS_MAP_INVALID         (0.0/0.0)

### OSM_GPS_MAP_CACHE_DISABLED

    #define OSM_GPS_MAP_CACHE_DISABLED  "none://"

### OSM_GPS_MAP_CACHE_AUTO

    #define OSM_GPS_MAP_CACHE_AUTO      "auto://"

### OSM_GPS_MAP_CACHE_FRIENDLY

    #define OSM_GPS_MAP_CACHE_FRIENDLY  "friendly://"

### enum OsmGpsMapSource_t

#### Members

OSM_GPS_MAP_SOURCE_NULL |  |
OSM_GPS_MAP_SOURCE_OPENSTREETMAP |  |
OSM_GPS_MAP_SOURCE_OPENSTREETMAP_RENDERER |  |
OSM_GPS_MAP_SOURCE_OPENAERIALMAP |  |
OSM_GPS_MAP_SOURCE_MAPS_FOR_FREE |  |
OSM_GPS_MAP_SOURCE_OPENCYCLEMAP |  |
OSM_GPS_MAP_SOURCE_OSM_PUBLIC_TRANSPORT |  |
OSM_GPS_MAP_SOURCE_GOOGLE_STREET |  |
OSM_GPS_MAP_SOURCE_GOOGLE_SATELLITE |  |
OSM_GPS_MAP_SOURCE_GOOGLE_HYBRID |  |
OSM_GPS_MAP_SOURCE_VIRTUAL_EARTH_STREET |  |
OSM_GPS_MAP_SOURCE_VIRTUAL_EARTH_SATELLITE |  |
OSM_GPS_MAP_SOURCE_VIRTUAL_EARTH_HYBRID |  |
OSM_GPS_MAP_SOURCE_OSMC_TRAILS |  |
OSM_GPS_MAP_SOURCE_LAST |  |

### enum OsmGpsMapKey_t

#### Members

OSM_GPS_MAP_KEY_FULLSCREEN |  |
OSM_GPS_MAP_KEY_ZOOMIN |  |
OSM_GPS_MAP_KEY_ZOOMOUT |  |
OSM_GPS_MAP_KEY_UP |  |
OSM_GPS_MAP_KEY_DOWN |  |
OSM_GPS_MAP_KEY_LEFT |  |
OSM_GPS_MAP_KEY_RIGHT |  |
OSM_GPS_MAP_KEY_MAX |  |

## Property Details

### The `“auto-center”` property

      “auto-center”              gboolean

map auto center.

Flags: Read / Write / Construct

Default value: TRUE

### The `“auto-center-threshold”` property

      “auto-center-threshold”    gfloat

the amount of the window the gps point must move before auto centering.

Flags: Read / Write / Construct

Allowed values: [0,1]

Default value: 0.25

### The `“auto-download”` property

      “auto-download”            gboolean

map auto download.

Flags: Read / Write / Construct

Default value: TRUE

### The `“drag-limit”` property

      “drag-limit”               gint

The number of pixels the user has to move the pointer in order to start dragging.

Flags: Read / Write / Construct Only

Allowed values: >= 0

Default value: 10

### The `“gps-track-highlight-radius”` property

      “gps-track-highlight-radius” gint

The radius of the gps point highlight circle.

Flags: Read / Write / Construct

Allowed values: >= 0

Default value: 20

### The `“gps-track-point-radius”` property

      “gps-track-point-radius”   gint

The radius of the gps point inner circle.

Flags: Read / Write / Construct

Allowed values: >= 0

Default value: 5

### The `“gps-track-width”` property

      “gps-track-width”          gfloat

The width of the lines drawn for the gps track.

Flags: Read / Write / Construct

Allowed values: [1,100]

Default value: 4

### The `“image-format”` property

      “image-format”             gchar *

The map source tile repository image format (jpg, png).

Flags: Read / Write / Construct Only

Default value: "png"

### The `“latitude”` property

      “latitude”                 gfloat

Latitude in degrees.

Flags: Read

Allowed values: [-90,90]

Default value: 0

### The `“longitude”` property

      “longitude”                gfloat

Longitude in degrees.

Flags: Read

Allowed values: [-180,180]

Default value: 0

### The `“map-source”` property

      “map-source”               gint

A OsmGpsMapSource_t representing the tile repository to use

If you do not wish to use the default map tiles (provided by OpenStreeMap) it is recommened that you set this property at construction, instead of setting “repo-uri”.

Flags: Read / Write / Construct

Allowed values: >= -1

Default value: -1

### The `“map-x”` property

      “map-x”                    gint

Initial map x location.

Flags: Read / Write / Construct Only

Default value: 890

### The `“map-y”` property

      “map-y”                    gint

Initial map y location.

Flags: Read / Write / Construct Only

Default value: 515

### The `“max-zoom”` property

      “max-zoom”                 gint

Maximum zoom level.

Flags: Read / Write / Construct Only

Allowed values: [0,20]

Default value: 18

### The `“min-zoom”` property

      “min-zoom”                 gint

Minimum zoom level.

Flags: Read / Write / Construct Only

Allowed values: [0,20]

Default value: 1

### The `“proxy-uri”` property

      “proxy-uri”                gchar *

HTTP proxy uri or NULL.

Flags: Read / Write / Construct Only

Default value: NULL

### The `“record-trip-history”` property

      “record-trip-history”      gboolean

should all gps points be recorded in a trip history.

Flags: Read / Write / Construct

Default value: TRUE

### The `“repo-uri”` property

      “repo-uri”                 gchar *

A URI string which defines the location and format to fetch tiles for the map. The string is of the format "http://tile.openstreetmap.org/#Z/#X/#Y.png". Characters that begin with # are treated as tokens and replaced according to the following rules;

- #X - X-tile, slippy map format

- #Y - Y-tile, slippy map format, mercator projection

- #Z - Zoom level, where min_zoom >= zoom <= max_zoom

- #S - Zoom level, where -max_zoom >= (zoom-max_zoom) <= min_zoom

- #Q - Quad tree format, set of "qrts"

- #Q0 - Quad tree format, set of "0123"

- #YS - Not Implemented

- #R - Random integer in range [0,4]

If you do not wish to use the default map tiles (provided by OpenStreeMap) it is recommened that you use one of the predefined map sources, and thus you should construct the map by setting “map-source” and not “repo-uri”. The “repo-uri” property is primarily designed for applications that wish complete control of tile repository management, or wish to use OsmGpsMap with a tile repository it does not explicitly support.

Flags: Read / Write / Construct Only

Default value: "http://tile.openstreetmap.org/#Z/#X/#Y.png"

### The `“show-gps-point”` property

      “show-gps-point”           gboolean

Controls whether the current gps point is shown on the map. Note that for derived classes that implement the draw_gps_point vfunc, if this property is `FALSE`

Flags: Read / Write / Construct

Default value: TRUE

### The `“show-trip-history”` property

      “show-trip-history”        gboolean

should the recorded trip history be shown on the map.

Flags: Read / Write / Construct

Default value: TRUE

### The `“tile-cache”` property

      “tile-cache”               gchar *

Either a full path or one of the special format URIs OSM_GPS_MAP_CACHE_DISABLED, OSM_GPS_MAP_CACHE_AUTO, OSM_GPS_MAP_CACHE_FRIENDLY. Also see “tile-cache-base” for a full understanding.

OSM_GPS_MAP_CACHE_DISABLED disables the on disk tile cache (so all tiles are fetched from the network. OSM_GPS_MAP_CACHE_AUTO causes the tile cache to be /tile-cache-base/md5(repo-uri), where md5 is the md5sum of “repo-uri”. OSM_GPS_MAP_CACHE_FRIENDLY causes the tile cache to be /tile-cache-base/friendlyname(repo-uri).

Any other string is interpreted as a local path, i.e. /path/to/cache

Flags: Read / Write / Construct

Default value: "auto://"

### The `“tile-cache-base”` property

      “tile-cache-base”          gchar *

The base directory of the tile cache when you have constructed the map with “tile-cache” set to OSM_GPS_MAP_CACHE_AUTO or OSM_GPS_MAP_CACHE_FRIENDLY

The string is interpreted as a local path, i.e. /path/to/cache. If NULL is supplied, map tiles are cached starting in the users cache directory, (as outlined in the

XDG Base Directory Specification). To get the

base directory where map tiles will be cached call `osm_gps_map_get_default_cache_directory()`

Flags: Read / Write / Construct Only

Default value: NULL

### The `“tile-zoom-offset”` property

      “tile-zoom-offset”         gint

Number of zoom-levels to upsample tiles.

Flags: Read / Write / Construct Only

Allowed values: [0,10]

Default value: 0

### The `“tiles-queued”` property

      “tiles-queued”             gint

The number of tiles currently waiting to download. Connect to ::notify::tiles-queued if you want to be informed when this changes

Flags: Read

Default value: 0

### The `“zoom”` property

      “zoom”                     gint

The map zoom level. Connect to ::notify::zoom if you want to be informed when this changes.

Flags: Read / Write / Construct Only

Allowed values: [0,20]

Default value: 3

## Signal Details

### The `“changed”` signal

    void
    user_function (OsmGpsMap *osmgpsmap,
                   gpointer   user_data)

The “changed” signal is emitted any time the map zoom or map center is chaged (such as by dragging or zooming).

If you are only interested in the map zoom, then you can simply connect to ::notify::zoom

#### Parameters

user_data | user data set when the signal handler was connected. |

Flags: Run First