- Qt 6.8
- Qt Location
- C++ Classes
- QGeoRoutingManager
- Qt 6.8.0 Reference Documentation

# QGeoRoutingManager Class

The QGeoRoutingManager class provides support for geographic routing operations. More...

Header: | #include <QGeoRoutingManager>
qmake: | QT += location
Inherits: | QObject

- List of all members, including inherited members

## Public Functions

virtual | ~QGeoRoutingManager()
QGeoRouteReply * | calculateRoute(const QGeoRouteRequest &request)
QLocale | locale() const
QString | managerName() const
int | managerVersion() const
QLocale::MeasurementSystem | measurementSystem() const
void | setLocale(const QLocale &locale)
void | setMeasurementSystem(QLocale::MeasurementSystem system)
QGeoRouteRequest::FeatureTypes | supportedFeatureTypes() const
QGeoRouteRequest::FeatureWeights | supportedFeatureWeights() const
QGeoRouteRequest::ManeuverDetails | supportedManeuverDetails() const
QGeoRouteRequest::RouteOptimizations | supportedRouteOptimizations() const
QGeoRouteRequest::SegmentDetails | supportedSegmentDetails() const
QGeoRouteRequest::TravelModes | supportedTravelModes() const
QGeoRouteReply * | updateRoute(const QGeoRoute &route, const QGeoCoordinate &position)

## Signals

void | errorOccurred(QGeoRouteReply *reply, QGeoRouteReply::Error error, const QString &errorString = QString())
void | finished(QGeoRouteReply *reply)

## Detailed Description

The calculateRoute() and updateRoute() methods function QGeoRouteReply objects, which manage these operations and report on the result of the operations and any errors which may have occurred.

The calculateRoute() function is used to find a route (or routes) that follows a set of waypoints and matches various other criteria. The QGeoRouteRequest class is used to specify this information.

If supportsRouteUpdates() returns true then the QGeoRoutingManager supports updating route information based on position updates. This will cause the travel time and distance estimates to be updated, and any QGeoRouteSegments already traversed to be removed from the route.

The updates can be triggered with the updateRoute() function, which makes use of the QGeoPositionInfo instances emitted as position updates by QGeoPositionInfoSource.

Instances of QGeoRoutingManager can be accessed with QGeoServiceProvider::routingManager().

A small example of the usage of QGeoRoutingManager and QGeoRouteRequests follows:

     class RouteHandler : public QObject
     {
         Q_OBJECT
     public:
         RouteHandler(QGeoRoutingManager *routingManager,
                        const QGeoCoordinate &origin,
                        const QGeoCoordinate &destination) {

             QGeoRouteRequest request(origin, destination);

             // The request defaults to the fastest route by car, which is
             // equivalent to:
             // request.setTravelMode(QGeoRouteRequest::CarTravel);
             // request.setRouteOptimization(QGeoRouteRequest::FastestRoute);

             request.setAvoidFeatureTypes(QGeoRouteRequest::AvoidTolls);
             request.setAvoidFeatureTypes(QGeoRouteRequest::AvoidMotorPoolLanes);

             QGeoRouteRequest::AvoidFeaturesTypes avoidableFeatures = routingManager->supportedAvoidFeatureTypes();

             if (!(avoidableFeatures & request.avoidFeatureTypes())) {
                 // ... inform the user that the routing manager does not
                 // provide support for avoiding tolls and/or motor pool lanes ...
                 return;
             }

             QGeoRouteReply *reply = routingManager->calculateRoute(request);

             if (reply->isFinished()) {
                 if (reply->error() == QGeoRouteReply::NoError) {
                     routeCalculated(reply);
                 } else {
                     routeError(reply, reply->error(), reply->errorString());
                 }
                 return;
             }

             connect(routingManager, &QGeoRoutingManager::finished,
                     this, &RouteHandler::routeCalculated);

             connect(routingManager, &QGeoRoutingManager::errorOccurred,
                     this, &RouteHandler::routeError);
         }

     private slots:
         void routeCalculated(QGeoRouteReply *reply)
         {
             // A route request can ask for several alternative routes ...
             if (reply->routes().size() != 0) {

                 // ... but by default it will only get a single route
                 QGeoRoute route = reply->routes().at(0);

                 //... now we have to make use of the route ...
             }

             reply->deleteLater();
         }

         void routeError(QGeoRouteReply *reply, QGeoRouteReply:Error error, const QString &errorString)
         {
             // ... inform the user that an error has occurred ...
             reply->deleteLater();
         }
     };

## Member Function Documentation

### `[virtual noexcept]` QGeoRoutingManager::~QGeoRoutingManager()

Destroys this manager.

### QGeoRouteReply *QGeoRoutingManager::calculateRoute(const QGeoRouteRequest &request)

Begins the calculation of the route specified by request.

A QGeoRouteReply object will be returned, which can be used to manage the routing operation and to return the results of the operation.

This manager and the returned QGeoRouteReply object will emit signals indicating if the operation completes or if errors occur.

Once the operation has completed, QGeoRouteReply::routes can be used to retrieve the calculated route or routes.

If request includes features which are not supported by this manager, as reported by the methods in this manager, then a QGeoRouteReply::UnsupportedOptionError will occur.

The user is responsible for deleting the returned reply object, although this can be done in the slot connected to QGeoRoutingManager::finished(), QGeoRoutingManager::errorOccurred(), QGeoRouteReply::finished() or QGeoRouteReply::errorOccurred() with deleteLater().

### `[signal]` void QGeoRoutingManager::errorOccurred(QGeoRouteReply *reply, QGeoRouteReply::Error error, const QString &errorString = QString())

This signal is emitted when an error has been detected in the processing of reply. The QGeoRoutingManager::finished() signal will probably follow.

The error will be described by the error code error. If errorString is not empty it will contain a textual description of the error.

This signal and QGeoRouteReply::errorOccurred() will be emitted at the same time.

Note: Do not delete the reply object in the slot connected to this signal. Use deleteLater() instead.

### `[signal]` void QGeoRoutingManager::finished(QGeoRouteReply *reply)

This signal is emitted when reply has finished processing.

If reply::error() equals QGeoRouteReply::NoError then the processing finished successfully.

This signal and QGeoRouteReply::finished() will be emitted at the same time.

Note: Do not delete the reply object in the slot connected to this signal. Use deleteLater() instead.

### QLocale QGeoRoutingManager::locale() const

Returns the locale used to hint to this routing manager about what language to use for addresses and instructions.

See also setLocale().

### QString QGeoRoutingManager::managerName() const

Returns the name of the engine which implements the behaviour of this routing manager.

The combination of managerName() and managerVersion() should be unique amongst the plugin implementations.

### int QGeoRoutingManager::managerVersion() const

Returns the version of the engine which implements the behaviour of this routin manager.

The combination of managerName() and managerVersion() should be unique amongst the plugin implementations.

### QLocale::MeasurementSystem QGeoRoutingManager::measurementSystem() const

Returns the measurement system used by this manager.

If setMeasurementSystem() has been called then the value returned by this function may be different to that returned by locale().measurementSystem(). In which case the value returned by this function is what will be used by the manager.

See also setMeasurementSystem() and setLocale().

### void QGeoRoutingManager::setLocale(const QLocale &locale)

Sets the locale to be used by this manager to locale.

If this routing manager supports returning addresses and instructions in different languages, they will be returned in the language of locale.

The locale used defaults to the system locale if this is not set.

See also locale().

### void QGeoRoutingManager::setMeasurementSystem(QLocale::MeasurementSystem system)

Sets the measurement system used by this manager to system.

The measurement system can be set independently of the locale. Both setLocale() and this function set the measurement system. The value set by the last function called will be used.

See also measurementSystem(), locale(), and setLocale().

### QGeoRouteRequest::FeatureTypes QGeoRoutingManager::supportedFeatureTypes() const

Returns the types of features that this manager can take into account during route planning.

### QGeoRouteRequest::FeatureWeights QGeoRoutingManager::supportedFeatureWeights() const

Returns the weightings which this manager can apply to different features during route planning.

### QGeoRouteRequest::ManeuverDetails QGeoRoutingManager::supportedManeuverDetails() const

Returns the levels of detail for navigation maneuvers which can be requested by this manager.

### QGeoRouteRequest::RouteOptimizations QGeoRoutingManager::supportedRouteOptimizations() const

Returns the route optimizations supported by this manager.

### QGeoRouteRequest::SegmentDetails QGeoRoutingManager::supportedSegmentDetails() const

Returns the levels of detail for routing segments which can be requested with this manager.

### QGeoRouteRequest::TravelModes QGeoRoutingManager::supportedTravelModes() const

Returns the travel modes supported by this manager.

### QGeoRouteReply *QGeoRoutingManager::updateRoute(const QGeoRoute &route, const QGeoCoordinate &position)

Begins the process of updating route based on the current position position.

A QGeoRouteReply object will be returned, which can be used to manage the routing operation and to return the results of the operation.

This manager and the returned QGeoRouteReply object will emit signals indicating if the operation completes or if errors occur.

If supportsRouteUpdates() returns false an QGeoRouteReply::UnsupportedOptionError will occur.

Once the operation has completed, QGeoRouteReply::routes can be used to retrieve the updated route.

The returned route could be entirely different to the original route, especially if position is far away from the initial route. Otherwise the route will be similar, although the remaining time and distance will be updated and any segments of the original route which have been traversed will be removed.

The user is responsible for deleting the returned reply object, although this can be done in the slot connected to QGeoRoutingManager::finished(), QGeoRoutingManager::errorOccurred(), QGeoRouteReply::finished() or QGeoRouteReply::errorOccurred() with deleteLater().