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QGeoAreaMonitor ClassThe QGeoAreaMonitor class enables the detection of proximity changes for a specified set of coordinates. More... #include <QGeoAreaMonitor>Inherits: QObject. This class was introduced in Qt Location 5.0. Properties
Public Functions
Signals
Static Public Members
Additional Inherited MembersDetailed DescriptionThe QGeoAreaMonitor class enables the detection of proximity changes for a specified set of coordinates. A QGeoAreaMonitor emits signals when the current position is in range, or has moved out of range, of a specified circular area. The area is specified by a coordinate (the center point) and a radius (in meters). For example: public: MyClass::MyClass() { QGeoAreaMonitor *monitor = QGeoAreaMonitor::createDefaultMonitor(); if (monitor) { connect(monitor, SIGNAL(areaEntered(QGeoPositionInfo)), this, SLOT(areaEntered(QGeoPositionInfo))); connect(monitor, SIGNAL(areaExited(QGeoPositionInfo)), this, SLOT(areaExited(QGeoPositionInfo))); QGeoCoordinate bigBenLocation(51.50104, -0.124632); monitor->setCenter(bigBenLocation); monitor->setRadius(100); } else { qDebug() << "Could not create default area monitor"; } } public Q_SLOTS: void areaEntered(const QGeoPositionInfo &update) { qDebug() << "Now within 100 meters, current position is" << update.coordinate(); } void areaExited(const QGeoPositionInfo &update) { qDebug() << "No longer within 100 meters, current position is" << update.coordinate(); } Property Documentation
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| QGeoCoordinate | center() const |
| virtual void | setCenter(const QGeoCoordinate & coordinate) |
radius : qreal
This property holds the radius of the area to be monitored, in meters.
If the specified radius is less than the minimum supported radius, the radius is set to the minimum radius.
When this property is set, if the center coordinate has already been set and the current position is within the monitored area, areaEntered() is emitted immediately.
By default, this property is 0.
Note: Subclass implementations must call the base implementation of setRadius() so that radius() returns the correct value.
Access functions:
| qreal | radius() const |
| virtual void | setRadius(qreal radius) |
Member Function Documentation
QGeoAreaMonitor::QGeoAreaMonitor(QObject * parent)
Creates a monitor with the given parent.
QGeoAreaMonitor::~QGeoAreaMonitor() [pure virtual]
Destroys the monitor.
void QGeoAreaMonitor::areaEntered(const QGeoPositionInfo & update) [signal]
Emitted when the current position has moved from a position outside the monitored area to a position within the monitored area.
The update holds the new position.
void QGeoAreaMonitor::areaExited(const QGeoPositionInfo & update) [signal]
Emitted when the current position has moved from a position within the monitored area to a position outside the monitored area.
The update holds the new position.
QGeoAreaMonitor * QGeoAreaMonitor::createDefaultMonitor(QObject * parent) [static]
Creates and returns a monitor with the given parent that monitors areas using resources on the underlying system.
Returns 0 if the system has no support for position monitoring.