- Qt 6.9
- Qt Positioning
- C++ Classes
- QGeoPolygon
- Qt 6.9.2 Reference Documentation

# QGeoPolygon Class

The QGeoPolygon class defines a geographic polygon. More...

Header: | `#include <QGeoPolygon>`
CMake: | `find_package(Qt6 REQUIRED COMPONENTS Positioning)` `target_link_libraries(mytarget PRIVATE Qt6::Positioning)`
qmake: | `QT += positioning`
Inherits: | QGeoShape

- List of all members, including inherited members

## Public Functions

| QGeoPolygon()
| QGeoPolygon(const QGeoShape &other)
| QGeoPolygon(const QList<QGeoCoordinate> &path)
| QGeoPolygon(const QGeoPolygon &other)
| ~QGeoPolygon()
void | addCoordinate(const QGeoCoordinate &coordinate)
void | addHole(const QList<QGeoCoordinate> &holePath)
void | addHole(const QVariant &holePath)
bool | containsCoordinate(const QGeoCoordinate &coordinate) const
QGeoCoordinate | coordinateAt(qsizetype index) const
const QVariantList | hole(qsizetype index) const
const QList<QGeoCoordinate> | holePath(qsizetype index) const
qsizetype | holesCount() const
void | insertCoordinate(qsizetype index, const QGeoCoordinate &coordinate)
double | length(qsizetype indexFrom = 0, qsizetype indexTo = -1) const
`(since QtPositioning 5.12)` const QList<QGeoCoordinate> & | perimeter() const
void | removeCoordinate(const QGeoCoordinate &coordinate)
void | removeCoordinate(qsizetype index)
void | removeHole(qsizetype index)
void | replaceCoordinate(qsizetype index, const QGeoCoordinate &coordinate)
`(since QtPositioning 5.12)` void | setPerimeter(const QList<QGeoCoordinate> &path)
qsizetype | size() const
QString | toString() const
void | translate(double degreesLatitude, double degreesLongitude)
QGeoPolygon | translated(double degreesLatitude, double degreesLongitude) const
QGeoPolygon & | operator=(const QGeoPolygon &other)

## Detailed Description

The polygon is defined by an ordered list of QGeoCoordinate objects representing its perimeter.

Each two adjacent elements in this list are intended to be connected together by the shortest line segment of constant bearing passing through both elements. This type of connection can cross the date line in the longitudinal direction, but never crosses the poles.

This is relevant for the calculation of the bounding box returned by QGeoShape::boundingGeoRectangle() for this shape, which will have the latitude of the top left corner set to the maximum latitude in the path point set. Similarly, the latitude of the bottom right corner will be the minimum latitude in the path point set.

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

## Member Function Documentation

### QGeoPolygon::QGeoPolygon()

Constructs a new, empty geo polygon.

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

Constructs a new geo polygon from the contents of other.

### QGeoPolygon::QGeoPolygon(const QList<QGeoCoordinate> &path)

Constructs a new geo polygon from the coordinates specified in path.

### QGeoPolygon::QGeoPolygon(const QGeoPolygon &other)

Constructs a new geo polygon from the contents of other.

### `[noexcept]` QGeoPolygon::~QGeoPolygon()

Destroys this polygon.

### `[invokable]` void QGeoPolygon::addCoordinate(const QGeoCoordinate &coordinate)

Appends coordinate to the polygon.

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

### void QGeoPolygon::addHole(const QList<QGeoCoordinate> &holePath)

Overloaded method. Sets the holePath for a hole inside the polygon. The hole is a QList<QGeoCoordinate>.

### `[invokable]` void QGeoPolygon::addHole(const QVariant &holePath)

Sets the holePath for a hole inside the polygon. The hole is a QVariant containing a QList<QGeoCoordinate>.

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

### `[invokable]` bool QGeoPolygon::containsCoordinate(const QGeoCoordinate &coordinate) const

Returns true if the polygon's perimeter contains coordinate as one of the elements.

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

### `[invokable]` QGeoCoordinate QGeoPolygon::coordinateAt(qsizetype index) const

Returns the coordinate at index .

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

### `[invokable]` const QVariantList QGeoPolygon::hole(qsizetype index) const

Returns a QVariant containing a QList<QGeoCoordinate> which represents the hole at index.

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

### const QList<QGeoCoordinate> QGeoPolygon::holePath(qsizetype index) const

Returns a QList<QGeoCoordinate> which represents the hole at index.

### `[invokable]` qsizetype QGeoPolygon::holesCount() const

Returns the number of holes.

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

### `[invokable]` void QGeoPolygon::insertCoordinate(qsizetype index, const QGeoCoordinate &coordinate)

Inserts coordinate at the specified index.

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

### `[invokable]` double QGeoPolygon::length(qsizetype indexFrom = 0, qsizetype indexTo = -1) const

Returns the length of the polygon's perimeter, in meters, from the element indexFrom to the element indexTo. The length is intended to be the sum of the shortest distances for each pair of adjacent points.

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

### `[since QtPositioning 5.12]` const QList<QGeoCoordinate> &QGeoPolygon::perimeter() const

Returns all the elements of the polygon's perimeter.

Note: Getter function for property perimeter.

This function was introduced in QtPositioning 5.12.

See also setPerimeter().

### `[invokable]` void QGeoPolygon::removeCoordinate(const QGeoCoordinate &coordinate)

Removes the last occurrence of coordinate from the polygon.

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

### `[invokable]` void QGeoPolygon::removeCoordinate(qsizetype index)

Removes element at position index from the polygon.

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

### `[invokable]` void QGeoPolygon::removeHole(qsizetype index)

Removes element at position index from the list of holes.

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

### `[invokable]` void QGeoPolygon::replaceCoordinate(qsizetype index, const QGeoCoordinate &coordinate)

Replaces the path element at the specified index with coordinate.

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

### `[since QtPositioning 5.12]` void QGeoPolygon::setPerimeter(const QList<QGeoCoordinate> &path)

Sets the perimeter of the polygon based on a list of coordinates path.

Note: Setter function for property perimeter.

This function was introduced in QtPositioning 5.12.

See also perimeter().

### `[invokable]` qsizetype QGeoPolygon::size() const

Returns the number of elements in the polygon.

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

### `[invokable]` QString QGeoPolygon::toString() const

Returns the geo polygon properties as a string.

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

### `[invokable]` void QGeoPolygon::translate(double degreesLatitude, double degreesLongitude)

Translates this geo polygon 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.

### `[invokable]` QGeoPolygon QGeoPolygon::translated(double degreesLatitude, double degreesLongitude) const

Returns a copy of this geo polygon 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().

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

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