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/*
FIXME: Remember to unref the needed things!
*/
using ContextProvider;
namespace ContextKit {
namespace Location2 {
// Data type for the locally stored location data
struct LocationData {
public double latitude;
public double longitude;
public double altitude;
public bool latlong_valid;
public bool altitude_valid;
}
public class Provider : GLib.Object, ContextProvider.Provider {
ProviderMixins.SubscriberList subscribed;
// contextd keys this plugin takes care of
const Key[] keys = {
{
"Context.Environment.Location.latitude",
ValueType.DOUBLE
},
{
"Context.Environment.Location.longitude",
ValueType.DOUBLE
},
{
"Context.Environment.Location.altitude",
ValueType.DOUBLE
}
};
StringSet location_keys;
StringSet subscribed_keys = new StringSet();
// Stores the last known location
static LocationData current_location;
// Device for using liblocation
Location.GPSDevice m_device;
void subscription_removed (ProviderMixins.SubscriberList l, Subscriber s) {
// TODO: Check here whether the connection to the loc service should be closed?
// FIXME: Do we have to remove it from the subscription list manually? Should the subscription list be part of the superclass?
}
/* Constructor
Connect the liblocation signals to correct functions.
Possibly: Indicate to liblocation that we're intrested in location data and start listening.
*/
public Provider () {
// Create plugin-related data structures
subscribed = new ProviderMixins.SubscriberList();
subscribed.removed += subscription_removed;
location_keys = new StringSet.from_array (new string[] {
"Context.Environment.Location.latitude",
"Context.Environment.Location.longitude",
"Context.Environment.Location.altitude"
});
// Invalidate the initial data
current_location.latlong_valid = false;
current_location.altitude_valid = false;
// Fetch an instance of the LocationGPSDControl
Location.GPSDControl control;
control = control.get_default();
// Connect signals from LocationGPSDControl
control.error += CB_Error;
control.gpsd_running += CB_Running;
control.gpsd_stopped += CB_Stopped;
// Indicate that we want to use only ACWP to avoid starting the GPS if it is not already running.
control.preferred_method = Location.Method.ACWP;
control.start(); // FIXME: This is only for testing.
// Create a LocationGPSDevice
m_device = new Location.GPSDevice();
// Connect signals from device
m_device.changed += CB_Changed;
m_device.connected += CB_Connected;
m_device.disconnected += CB_Disconnected;
m_device.start(); // FIXME: This is only for testing
// FIXME: Do we need to unref control? Or does Vala handle it automatically?
}
// Destructor
~Provider() {
// FIXME: Deleting / freeing / ... the device? How? Or does Vala handle it automatically?
}
// Handling signals from GPS control
static void CB_Error(Location.GPSDControl? control) {
debug("Error");
}
static void CB_Running(Location.GPSDControl? control) {
debug("Running");
}
static void CB_Stopped(Location.GPSDControl? control) {
debug("Stopped");
}
// Handling signals from GPS device
void CB_Changed(Location.GPSDevice? device) {
bool values_changed = false;
if (device != null && device.fix != null) {
debug("Changed %f %f %f", device.fix.latitude, device.fix.longitude, device.fix.altitude);
if ((device.fix.fields & Location.GPS_DEVICE_LATLONG_SET) != 0) {
if (current_location.latitude != device.fix.latitude) {
values_changed = true;
}
if (current_location.longitude != device.fix.longitude) {
values_changed = true;
}
current_location.latitude = device.fix.latitude;
current_location.longitude = device.fix.longitude;
current_location.latlong_valid = true;
}
if ((device.fix.fields & Location.GPS_DEVICE_ALTITUDE_SET) != 0) {
if (current_location.altitude != device.fix.altitude) {
values_changed = true;
}
current_location.altitude = device.fix.altitude;
current_location.altitude_valid = true;
}
// TODO: Tresholds? If the values change only a little, ignore the change?
}
HashTable<string, TypedVariant?> ret = new HashTable<string, TypedVariant?> (str_hash,str_equal);
if (subscribed_keys.is_member ("Context.Environment.Location.latitude")) {
insert_double_key("Context.Environment.Location.latitude", ret, current_location.latitude, current_location.latlong_valid);
}
if (subscribed_keys.is_member ("Context.Environment.Location.longitude")) {
insert_double_key("Context.Environment.Location.longitude", ret, current_location.longitude, current_location.latlong_valid);
}
if (subscribed_keys.is_member ("Context.Environment.Location.altitude")) {
insert_double_key("Context.Environment.Location.altitude", ret, current_location.altitude, current_location.altitude_valid);
}
// TODO: Should we check whether we need the location service any more?
// If we stop the connecton, we won't be able to answer future Get:s accurately.
/* Note: We always emit the same kind of changed signal, not depending on which values have
actually changed. */
if (values_changed) {
// Emit the "Changed" signal
for (int i=0; i < subscribed.size; i++) {
weak Subscriber s = subscribed.get(i);
s.emit_changed(ret);
}
// TODO: Emit only for those who are intrested in the changed keys?
}
}
static void CB_Connected(Location.GPSDevice device) {
debug("Connected");
}
static void CB_Disconnected(Location.GPSDevice device) {
debug("Disconnected");
}
void insert_double_key (string key, HashTable<string, TypedVariant?> ret, double double_value, bool do_insert) {
Value v = Value (typeof(double));
if (do_insert) {
v.set_double(double_value);
ret.insert (key, TypedVariant (ValueType.DOUBLE, v));
}
else {
v.set_double (0);
ret.insert (key, TypedVariant (ValueType.UNDETERMINED, v));
}
}
public void Get (StringSet keys, HashTable<string, TypedVariant?> ret) {
if (keys.is_disjoint (location_keys)) {
return;
}
/*
Note: If this is the first Get (and we don't start the service before this), the data may not be valid.
*/
// Copy the internally stored information to the map
if (keys.is_member ("Context.Environment.Location.latitude")) {
insert_double_key("Context.Environment.Location.latitude", ret, current_location.latitude, current_location.latlong_valid);
}
if (keys.is_member ("Context.Environment.Location.longitude")) {
insert_double_key("Context.Environment.Location.longitude", ret, current_location.longitude, current_location.latlong_valid);
}
if (keys.is_member ("Context.Environment.Location.altitude")) {
insert_double_key("Context.Environment.Location.altitude", ret, current_location.altitude, current_location.altitude_valid);
}
}
public void Subscribe (StringSet keys, ContextProvider.Subscriber s) {
// FIXME: These are common to all plugins --> move to some upper level
subscribed.add (s);
subscribed_keys = new StringSet.union (subscribed_keys, keys);
// FIXME: Also an intersection is needed.
}
public Key[] Keys() {
return keys;
}
}
}
}
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