Add distance to home to Vehicle FactGroup

src/Vehicle/Vehicle.cc

@@ -55,6 +55,7 @@ const char* Vehicle::_altitudeRelativeFactName =    "altitudeRelative";
 const char* Vehicle::_altitudeAMSLFactName =        "altitudeAMSL";
 const char* Vehicle::_flightDistanceFactName =      "flightDistance";
 const char* Vehicle::_flightTimeFactName =          "flightTime";
+const char* Vehicle::_distanceToHomeFactName =      "distanceToHome";
 
 const char* Vehicle::_gpsFactGroupName =        "gps";
 const char* Vehicle::_batteryFactGroupName =    "battery";
@@ -160,6 +161,7 @@ Vehicle::Vehicle(LinkInterface*             link,
     , _altitudeAMSLFact     (0, _altitudeAMSLFactName,      FactMetaData::valueTypeDouble)
     , _flightDistanceFact   (0, _flightDistanceFactName,    FactMetaData::valueTypeDouble)
     , _flightTimeFact       (0, _flightTimeFactName,        FactMetaData::valueTypeElapsedTimeInSeconds)
+    , _distanceToHomeFact   (0, _distanceToHomeFactName,    FactMetaData::valueTypeDouble)
     , _gpsFactGroup(this)
     , _batteryFactGroup(this)
     , _windFactGroup(this)
@@ -325,6 +327,7 @@ Vehicle::Vehicle(MAV_AUTOPILOT              firmwareType,
     , _altitudeAMSLFact     (0, _altitudeAMSLFactName,      FactMetaData::valueTypeDouble)
     , _flightDistanceFact   (0, _flightDistanceFactName,    FactMetaData::valueTypeDouble)
     , _flightTimeFact       (0, _flightTimeFactName,        FactMetaData::valueTypeElapsedTimeInSeconds)
+    , _distanceToHomeFact   (0, _distanceToHomeFactName,    FactMetaData::valueTypeDouble)
     , _gpsFactGroup(this)
     , _batteryFactGroup(this)
     , _windFactGroup(this)
@@ -338,6 +341,9 @@ void Vehicle::_commonInit(void)
 {
     _firmwarePlugin = _firmwarePluginManager->firmwarePluginForAutopilot(_firmwareType, _vehicleType);
 
+    connect(this, &Vehicle::coordinateChanged,      this, &Vehicle::_updateDistanceToHome);
+    connect(this, &Vehicle::homePositionChanged,    this, &Vehicle::_updateDistanceToHome);
+
     _missionManager = new MissionManager(this);
     connect(_missionManager, &MissionManager::error,                    this, &Vehicle::_missionManagerError);
     connect(_missionManager, &MissionManager::newMissionItemsAvailable, this, &Vehicle::_missionLoadComplete);
@@ -376,6 +382,7 @@ void Vehicle::_commonInit(void)
     _addFact(&_altitudeAMSLFact,        _altitudeAMSLFactName);
     _addFact(&_flightDistanceFact,      _flightDistanceFactName);
     _addFact(&_flightTimeFact,          _flightTimeFactName);
+    _addFact(&_distanceToHomeFact,      _distanceToHomeFactName);
 
     _addFactGroup(&_gpsFactGroup,       _gpsFactGroupName);
     _addFactGroup(&_batteryFactGroup,   _batteryFactGroupName);
@@ -2798,6 +2805,15 @@ void Vehicle::_handleADSBVehicle(const mavlink_message_t& message)
     }
 }
 
+void Vehicle::_updateDistanceToHome(void)
+{
+    if (coordinate().isValid() && homePosition().isValid()) {
+        _distanceToHomeFact.setRawValue(coordinate().distanceTo(homePosition()));
+    } else {
+        _distanceToHomeFact.setRawValue(qQNaN());
+    }
+}
+
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
 

src/Vehicle/Vehicle.h

@@ -348,6 +348,7 @@ public:
     Q_PROPERTY(Fact* altitudeRelative   READ altitudeRelative   CONSTANT)
     Q_PROPERTY(Fact* altitudeAMSL       READ altitudeAMSL       CONSTANT)
     Q_PROPERTY(Fact* flightDistance     READ flightDistance     CONSTANT)
+    Q_PROPERTY(Fact* distanceToHome     READ distanceToHome     CONSTANT)
 
     Q_PROPERTY(FactGroup* gps         READ gpsFactGroup         CONSTANT)
     Q_PROPERTY(FactGroup* battery     READ batteryFactGroup     CONSTANT)
@@ -613,6 +614,7 @@ public:
     Fact* altitudeRelative  (void) { return &_altitudeRelativeFact; }
     Fact* altitudeAMSL      (void) { return &_altitudeAMSLFact; }
     Fact* flightDistance    (void) { return &_flightDistanceFact; }
+    Fact* distanceToHome    (void) { return &_distanceToHomeFact; }
 
     FactGroup* gpsFactGroup         (void) { return &_gpsFactGroup; }
     FactGroup* batteryFactGroup     (void) { return &_batteryFactGroup; }
@@ -825,6 +827,7 @@ private slots:
     void _activeJoystickChanged(void);
     void _clearTrajectoryPoints(void);
     void _clearCameraTriggerPoints(void);
+    void _updateDistanceToHome(void);
 
 private:
     bool _containsLink(LinkInterface* link);
@@ -1042,6 +1045,7 @@ private:
     Fact _altitudeAMSLFact;
     Fact _flightDistanceFact;
     Fact _flightTimeFact;
+    Fact _distanceToHomeFact;
 
     VehicleGPSFactGroup         _gpsFactGroup;
     VehicleBatteryFactGroup     _batteryFactGroup;
@@ -1059,6 +1063,7 @@ private:
     static const char* _altitudeAMSLFactName;
     static const char* _flightDistanceFactName;
     static const char* _flightTimeFactName;
+    static const char* _distanceToHomeFactName;
 
     static const char* _gpsFactGroupName;
     static const char* _batteryFactGroupName;

src/Vehicle/VehicleFact.json

@@ -63,6 +63,13 @@
     "units":            "m"
 },
 {
+    "name":             "distanceToHome",
+    "shortDescription": "Distance to Home",
+    "type":             "double",
+    "decimalPlaces":    1,
+    "units":            "m"
+},
+{
     "name":             "flightTime",
     "shortDescription": "Flight Time",
     "type":             "elapsedSeconds",