GypsyCourse

GypsyCourse — Object for obtaining course information

Synopsis




                    GypsyCourse;
#define             GYPSY_COURSE_DBUS_INTERFACE
#define             GYPSY_COURSE_DBUS_SERVICE
enum                GypsyCourseFields;
GypsyCourse*        gypsy_course_new                    (const char *object_path);
GypsyCourseFields   gypsy_course_get_course             (GypsyCourse *course,
                                                         int *timestamp,
                                                         double *speed,
                                                         double *direction,
                                                         double *climb,
                                                         GError **error);

Object Hierarchy


  GObject
   +----GypsyCourse

Properties


  "object-path"              gchararray            : Write / Construct Only

Signals


  "course-changed"                                 : Run First / No Recursion

Description

GypsyCourse is used whenever the client program wishes to know about GPS course changes. It can report the current course, and has a signal to notify listeners of changes. The course consists of the speed, direction and rate of ascent or descent (called the climb).

A GypsyCourse object is created using gypsy_course_new() using the D-Bus path of the GPS device. This path is returned from the gypsy_control_create() function. The client can then find out about the course with gypsy_course_get_course().

As the course information changes GypsyCourse will emit the course-changed signal. This signal contains the course information if gypsy-daemon knows it. It has a fields paramater which is a bitmask of GypsyCourseFields which indicates which of the speed, direction or climb contains valid information. The timestamp will always be valid if it is greater than 0. 

GypsyCourse *course;
GError *error = NULL;

. . .

/ * path comes from the gypsy_control_create() function * /
course = gypsy_course_new (path);
g_signal_connect (course, "course-changed", G_CALLBACK (course_changed), NULL);

. . .

static void 
course_changed (GypsyCourse *course, 
GypsyCourseFields fields,
int timestamp,
double speed,
double direction,
double climb,
gpointer userdata)
{
  g_print ("speed: %fm/s\n", (fields & GYPSY_COURSE_FIELDS_SPEED) ? speed : -1.0);
}

Details

GypsyCourse

typedef struct _GypsyCourse GypsyCourse;

There are no public fields in GypsyCourse.

GYPSY_COURSE_DBUS_INTERFACE

#define GYPSY_COURSE_DBUS_INTERFACE "org.freedesktop.Gypsy.Course"

A define containing the name of the Course interface

GYPSY_COURSE_DBUS_SERVICE

#define GYPSY_COURSE_DBUS_SERVICE "org.freedesktop.Gypsy"

A define containing the address of the Course service

enum GypsyCourseFields

typedef enum {
	GYPSY_COURSE_FIELDS_NONE = 1 << 0,
	GYPSY_COURSE_FIELDS_SPEED = 1 << 1,
	GYPSY_COURSE_FIELDS_DIRECTION = 1 << 2,
	GYPSY_COURSE_FIELDS_CLIMB = 1 << 3
} GypsyCourseFields;

A bitfield telling which fields in the course_changed callback are valid

GYPSY_COURSE_FIELDS_NONE None of the fields are valid
GYPSY_COURSE_FIELDS_SPEED The speed field is valid
GYPSY_COURSE_FIELDS_DIRECTION The direction field is valid
GYPSY_COURSE_FIELDS_CLIMB The climb field is valid

gypsy_course_new ()

GypsyCourse*        gypsy_course_new                    (const char *object_path);

Creates a new GypsyCourse object that listens for course changes from the GPS device found at object_path.

object_path : Object path to the GPS device.
Returns : A GypsyCourse object

gypsy_course_get_course ()

GypsyCourseFields   gypsy_course_get_course             (GypsyCourse *course,
                                                         int *timestamp,
                                                         double *speed,
                                                         double *direction,
                                                         double *climb,
                                                         GError **error);

Obtains the course details from course. timestamp, speed, direction and climb can be NULL if that detail is not required.

course : A GypsyCourse object
timestamp : Pointer for the timestamp to be returned
speed : Pointer for the speed to be returned
direction : Pointer for the direction to be returned
climb : Pointer for the climb to be returned
error : A GError for error return
Returns : A bitmask of the fields that are set.

Property Details

The "object-path" property

  "object-path"              gchararray            : Write / Construct Only

The path of the Gypsy GPS object

Default value: ""

Signal Details

The "course-changed" signal

void                user_function                      (GypsyCourse *fields,
                                                        gint         timestamp,
                                                        gint         speed,
                                                        gdouble      direction,
                                                        gdouble      climb,
                                                        gdouble      arg5,
                                                        gpointer     user_data)      : Run First / No Recursion

The ::course-changed signal is emitted when the GPS device indicates that one or more of the course fields has changed. The fields which have changed will be indicated in the fields bitmask.

fields : A bitmask of GypsyCourseFields indicating which of the following fields are valid
timestamp : The time this change occurred
speed : The new speed
direction : The new direction
climb : The new rate of climb
user_data : user data set when the signal handler was connected.