- Qt 5.15
- Qt Positioning
- C++ Classes
- QGeoCircle
- Qt 5.15.18 Reference Documentation

# QGeoCircle Class

The QGeoCircle class defines a circular geographic area. More...

Header: | #include <QGeoCircle>
qmake: | QT += positioning
Since: | Qt 5.2
Inherits: | QGeoShape

This class was introduced in Qt 5.2.

- List of all members, including inherited members

## Properties

- center : QGeoCoordinate
- radius : qreal

## Public Functions

| QGeoCircle(const QGeoShape &other)
| QGeoCircle(const QGeoCircle &other)
| QGeoCircle(const QGeoCoordinate &center, qreal radius = -1.0)
| QGeoCircle()
QGeoCircle & | operator=(const QGeoCircle &other)
| ~QGeoCircle()
QGeoCoordinate | center() const
void | extendCircle(const QGeoCoordinate &coordinate)
qreal | radius() const
void | setCenter(const QGeoCoordinate &center)
void | setRadius(qreal radius)
QString | toString() const
void | translate(double degreesLatitude, double degreesLongitude)
QGeoCircle | translated(double degreesLatitude, double degreesLongitude) const
bool | operator!=(const QGeoCircle &other) const
bool | operator==(const QGeoCircle &other) const

## Detailed Description

The circle is defined in terms of a QGeoCoordinate which specifies the center of the circle and a qreal which specifies the radius of the circle in meters.

The circle is considered invalid if the center coordinate is invalid or if the radius is less than zero.

This class is a Q_GADGET since Qt 5.5. It can be directly used from C++ and QML.

## Property Documentation

### center : QGeoCoordinate

This property holds the center coordinate for the geo circle.

The circle is considered invalid if this property contains an invalid coordinate.

A default constructed QGeoCircle uses an invalid QGeoCoordinate as center.

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:

QGeoCoordinate | center() const
void | setCenter(const QGeoCoordinate &center)

### radius : qreal

This property holds the circle radius in meters.

The circle is considered invalid if this property is negative.

By default, the radius is initialized with `-1`.

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:

qreal | radius() const
void | setRadius(qreal radius)

## Member Function Documentation

### QGeoCircle::QGeoCircle(const QGeoShape &other)

Constructs a new geo circle from the contents of other.

### QGeoCircle::QGeoCircle(const QGeoCircle &other)

Constructs a new geo circle from the contents of other.

### QGeoCircle::QGeoCircle(const QGeoCoordinate &center, qreal radius = -1.0)

Constructs a new geo circle centered at center and with a radius of radius meters.

### QGeoCircle::QGeoCircle()

Constructs a new, invalid geo circle.

### QGeoCircle &QGeoCircle::operator=(const QGeoCircle &other)

Assigns other to this geo circle and returns a reference to this geo circle.

### QGeoCircle::~QGeoCircle()

Destroys this geo circle.

### QGeoCoordinate QGeoCircle::center() const

Returns the center coordinate of this geo circle. Equivalent to QGeoShape::center().

Note: Getter function for property center.

See also setCenter().

### void QGeoCircle::extendCircle(const QGeoCoordinate &coordinate)

Extends the geo circle to also cover the coordinate coordinate

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

This function was introduced in Qt 5.9.

### qreal QGeoCircle::radius() const

Returns the radius in meters of this geo circle.

Note: Getter function for property radius.

See also setRadius().

### void QGeoCircle::setCenter(const QGeoCoordinate &center)

Sets the center coordinate of this geo circle to center.

Note: Setter function for property center.

See also center().

### void QGeoCircle::setRadius(qreal radius)

Sets the radius in meters of this geo circle to radius.

Note: Setter function for property radius.

See also radius().

### QString QGeoCircle::toString() const

Returns the geo circle properties as a string.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

This function was introduced in Qt 5.5.

### void QGeoCircle::translate(double degreesLatitude, double degreesLongitude)

Translates this geo circle by degreesLatitude northwards and degreesLongitude eastwards.

Negative values of degreesLatitude and degreesLongitude correspond to southward and westward translation respectively.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

### QGeoCircle QGeoCircle::translated(double degreesLatitude, double degreesLongitude) const

Returns a copy of this geo circle translated by degreesLatitude northwards and degreesLongitude eastwards.

Negative values of degreesLatitude and degreesLongitude correspond to southward and westward translation respectively.

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

See also translate().

### bool QGeoCircle::operator!=(const QGeoCircle &other) const

Returns whether this geo circle is not equal to other.

### bool QGeoCircle::operator==(const QGeoCircle &other) const

Returns whether this geo circle is equal to other.