QGeoCoordinate Class
The QGeoCoordinate class defines a geographical position on the surface of the Earth. More...
| Header: | #include <QGeoCoordinate> |
| qmake: | QT += positioning |
| Since: | Qt 5.2 |
This class was introduced in Qt 5.2.
Public Types
| enum | CoordinateFormat { Degrees, DegreesWithHemisphere, DegreesMinutes, DegreesMinutesWithHemisphere, DegreesMinutesSeconds, DegreesMinutesSecondsWithHemisphere } |
| enum | CoordinateType { InvalidCoordinate, Coordinate2D, Coordinate3D } |
Properties
Public Functions
| QGeoCoordinate(const QGeoCoordinate &other) | |
| QGeoCoordinate(double latitude, double longitude, double altitude) | |
| QGeoCoordinate(double latitude, double longitude) | |
| QGeoCoordinate() | |
| QGeoCoordinate & | operator=(const QGeoCoordinate &other) |
| ~QGeoCoordinate() | |
| double | altitude() const |
| QGeoCoordinate | atDistanceAndAzimuth(qreal distance, qreal azimuth, qreal distanceUp = 0.0) const |
| qreal | azimuthTo(const QGeoCoordinate &other) const |
| qreal | distanceTo(const QGeoCoordinate &other) const |
| bool | isValid() const |
| double | latitude() const |
| double | longitude() const |
| void | setAltitude(double altitude) |
| void | setLatitude(double latitude) |
| void | setLongitude(double longitude) |
| QString | toString(CoordinateFormat format = DegreesMinutesSecondsWithHemisphere) const |
| CoordinateType | type() const |
| bool | operator!=(const QGeoCoordinate &other) const |
| bool | operator==(const QGeoCoordinate &other) const |
Related Non-Members
| QDataStream & | operator<<(QDataStream &stream, const QGeoCoordinate &coordinate) |
| QDataStream & | operator>>(QDataStream &stream, QGeoCoordinate &coordinate) |
Detailed Description
A QGeoCoordinate is defined by latitude, longitude, and optionally, altitude.
Use type() to determine whether a coordinate is a 2D coordinate (has latitude and longitude only) or 3D coordinate (has latitude, longitude and altitude). Use distanceTo() and azimuthTo() to calculate the distance and bearing between coordinates.
The coordinate values should be specified using the WGS84 datum. For more information on geographical terms see this article on coordinates and another on geodetic systems including WGS84.
Azimuth in this context is equivalent to a compass bearing based on true north.
This class is a Q_GADGET since Qt 5.5. It can be directly used from C++ and QML.
Member Type Documentation
enum QGeoCoordinate::CoordinateFormat
Defines the possible formatting options for toString().
| Constant | Value | Description |
|---|---|---|
QGeoCoordinate::Degrees | 0 | Returns a string representation of the coordinates in decimal degrees format. |
QGeoCoordinate::DegreesWithHemisphere | 1 | Returns a string representation of the coordinates in decimal degrees format, using 'N', 'S', 'E' or 'W' to indicate the hemispheres of the coordinates. |
QGeoCoordinate::DegreesMinutes | 2 | Returns a string representation of the coordinates in degrees-minutes format. |
QGeoCoordinate::DegreesMinutesWithHemisphere | 3 | Returns a string representation of the coordinates in degrees-minutes format, using 'N', 'S', 'E' or 'W' to indicate the hemispheres of the coordinates. |
QGeoCoordinate::DegreesMinutesSeconds | 4 | Returns a string representation of the coordinates in degrees-minutes-seconds format. |
QGeoCoordinate::DegreesMinutesSecondsWithHemisphere | 5 | Returns a string representation of the coordinates in degrees-minutes-seconds format, using 'N', 'S', 'E' or 'W' to indicate the hemispheres of the coordinates. |
See also toString().
enum QGeoCoordinate::CoordinateType
Defines the types of a coordinate.
| Constant | Value | Description |
|---|---|---|
QGeoCoordinate::InvalidCoordinate | 0 | An invalid coordinate. A coordinate is invalid if its latitude or longitude values are invalid. |
QGeoCoordinate::Coordinate2D | 1 | A coordinate with valid latitude and longitude values. |
QGeoCoordinate::Coordinate3D | 2 | A coordinate with valid latitude and longitude values, and also an altitude value. |
Property Documentation
altitude : double
This property holds the altitude in meters above sea level.
The property is undefined (qQNaN()) if the altitude has not been set.
While this property is introduced in Qt 5.5, the related accessor functions exist since the first version of this class.
This property was introduced in Qt 5.5.
Access functions:
| double | altitude() const |
| void | setAltitude(double altitude) |
isValid : const bool
This property holds the validity of this geo coordinate.
The geo coordinate is valid if the longitude and latitude properties have been set to valid values.
While this property is introduced in Qt 5.5, the related accessor functions exist since the first version of this class.
This property was introduced in Qt 5.5.
Access functions:
| bool | isValid() const |
latitude : double
This property holds the latitude in decimal degrees.
The property is undefined (qQNaN()) if the latitude has not been set. A positive latitude indicates the Northern Hemisphere, and a negative latitude indicates the Southern Hemisphere. When setting the latitude the new value should be in the WGS84 datum format.
To be valid, the latitude must be between -90 to 90 inclusive.
While this property is introduced in Qt 5.5, the related accessor functions exist since the first version of this class.
This property was introduced in Qt 5.5.
Access functions:
| double | latitude() const |
| void | setLatitude(double latitude) |
longitude : double
This property holds the longitude in decimal degrees.
The property is undefined (qQNaN()) if the longitude has not been set. A positive longitude indicates the Eastern Hemisphere, and a negative longitude indicates the Western Hemisphere. When setting the longitude the new value should be in the WGS84 datum format.
To be valid, the longitude must be between -180 to 180 inclusive.
While this property is introduced in Qt 5.5, the related accessor functions exist since the first version of this class.
This property was introduced in Qt 5.5.
Access functions:
| double | longitude() const |
| void | setLongitude(double longitude) |
Member Function Documentation
QGeoCoordinate::QGeoCoordinate(const QGeoCoordinate &other)
Constructs a coordinate from the contents of other.
QGeoCoordinate::QGeoCoordinate(double latitude, double longitude, double altitude)
Constructs a coordinate with the given latitude, longitude and altitude.
If the latitude is not between -90 to 90 inclusive, or the longitude is not between -180 to 180 inclusive, none of the values are set and the type() will be QGeoCoordinate::InvalidCoordinate.
Note that altitude specifies the meters above sea level.
See also isValid().
QGeoCoordinate::QGeoCoordinate(double latitude, double longitude)
Constructs a coordinate with the given latitude and longitude.
If the latitude is not between -90 to 90 inclusive, or the longitude is not between -180 to 180 inclusive, none of the values are set and the type() will be QGeoCoordinate::InvalidCoordinate.
See also isValid().
QGeoCoordinate::QGeoCoordinate()
Constructs a coordinate. The coordinate will be invalid until setLatitude() and setLongitude() have been called.
QGeoCoordinate &QGeoCoordinate::operator=(const QGeoCoordinate &other)
Assigns other to this coordinate and returns a reference to this coordinate.
QGeoCoordinate::~QGeoCoordinate()
Destroys the coordinate object.
double QGeoCoordinate::altitude() const
Returns the altitude (meters above sea level).
The return value is undefined if the altitude has not been set.
Note: Getter function for property altitude.
See also setAltitude() and type().
QGeoCoordinate QGeoCoordinate::atDistanceAndAzimuth(qreal distance, qreal azimuth, qreal distanceUp = 0.0) const
Returns the coordinate that is reached by traveling distance meters from the current coordinate at azimuth (or bearing) along a great-circle. There is an assumption that the Earth is spherical for the purpose of this calculation.
The altitude will have distanceUp added to it.
Returns an invalid coordinate if this coordinate is invalid.
Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.
qreal QGeoCoordinate::azimuthTo(const QGeoCoordinate &other) const
Returns the azimuth (or bearing) in degrees from this coordinate to the coordinate specified by other. Altitude is not used in the calculation.
The bearing returned is the bearing from the origin to other along the great-circle between the two coordinates. There is an assumption that the Earth is spherical for the purpose of this calculation.
Returns 0 if the type of this coordinate or the type of other is QGeoCoordinate::InvalidCoordinate.
Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.
qreal QGeoCoordinate::distanceTo(const QGeoCoordinate &other) const
Returns the distance (in meters) from this coordinate to the coordinate specified by other. Altitude is not used in the calculation.
This calculation returns the great-circle distance between the two coordinates, with an assumption that the Earth is spherical for the purpose of this calculation.
Returns 0 if the type of this coordinate or the type of other is QGeoCoordinate::InvalidCoordinate.
Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.
bool QGeoCoordinate::isValid() const
Returns true if the longitude and latitude are valid.
Note: Getter function for property isValid.
double QGeoCoordinate::latitude() const
Returns the latitude, in decimal degrees. The return value is undefined if the latitude has not been set.
A positive latitude indicates the Northern Hemisphere, and a negative latitude indicates the Southern Hemisphere.
Note: Getter function for property latitude.
See also setLatitude() and type().
double QGeoCoordinate::longitude() const
Returns the longitude, in decimal degrees. The return value is undefined if the longitude has not been set.
A positive longitude indicates the Eastern Hemisphere, and a negative longitude indicates the Western Hemisphere.
Note: Getter function for property longitude.
See also setLongitude() and type().
void QGeoCoordinate::setAltitude(double altitude)
Sets the altitude (meters above sea level) to altitude.
Note: Setter function for property altitude.
See also altitude().
void QGeoCoordinate::setLatitude(double latitude)
Sets the latitude (in decimal degrees) to latitude. The value should be in the WGS84 datum.
To be valid, the latitude must be between -90 to 90 inclusive.
Note: Setter function for property latitude.
See also latitude().
void QGeoCoordinate::setLongitude(double longitude)
Sets the longitude (in decimal degrees) to longitude. The value should be in the WGS84 datum.
To be valid, the longitude must be between -180 to 180 inclusive.
Note: Setter function for property longitude.
See also longitude().
QString QGeoCoordinate::toString(CoordinateFormat format = DegreesMinutesSecondsWithHemisphere) const
Returns this coordinate as a string in the specified format.
For example, if this coordinate has a latitude of -27.46758, a longitude of 153.027892 and an altitude of 28.1, these are the strings returned depending on format:
| format value | Returned string |
|---|---|
| Degrees | -27.46758°, 153.02789°, 28.1m |
| DegreesWithHemisphere | 27.46758° S, 153.02789° E, 28.1m |
| DegreesMinutes | -27° 28.054', 153° 1.673', 28.1m |
| DegreesMinutesWithHemisphere | 27° 28.054 S', 153° 1.673' E, 28.1m |
| DegreesMinutesSeconds | -27° 28' 3.2", 153° 1' 40.4", 28.1m |
| DegreesMinutesSecondsWithHemisphere | 27° 28' 3.2" S, 153° 1' 40.4" E, 28.1m |
The altitude field is omitted if no altitude is set.
If the coordinate is invalid, an empty string is returned.
Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.
CoordinateType QGeoCoordinate::type() const
Returns the type of this coordinate.
bool QGeoCoordinate::operator!=(const QGeoCoordinate &other) const
Returns true if latitude, longitude, or altitude of this coordinate are not identical to other.
bool QGeoCoordinate::operator==(const QGeoCoordinate &other) const
Returns true if the latitude, longitude and altitude of this coordinate are the same as those of other.
The longitude will be ignored if the latitude is +/- 90 degrees.
Related Non-Members
QDataStream &operator<<(QDataStream &stream, const QGeoCoordinate &coordinate)
Writes the given coordinate to the specified stream.
See also Serializing Qt Data Types.
QDataStream &operator>>(QDataStream &stream, QGeoCoordinate &coordinate)
Reads a coordinate from the specified stream into the given coordinate.
See also Serializing Qt Data Types.