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

# QGeoRoutingManagerEngine Class

The QGeoRoutingManagerEngine class provides an interface and convenience methods to implementers of QGeoServiceProvider plugins who want to provide access to geographic routing information. More...

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

- List of all members, including inherited members

## Public Functions

| QGeoRoutingManagerEngine(const QVariantMap &parameters, QObject *parent = nullptr)
virtual | ~QGeoRoutingManagerEngine()
virtual QGeoRouteReply * | calculateRoute(const QGeoRouteRequest &request) = 0
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
virtual QGeoRouteReply * | updateRoute(const QGeoRoute &route, const QGeoCoordinate &position)

## Signals

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

## Protected Functions

void | setSupportedFeatureTypes(QGeoRouteRequest::FeatureTypes featureTypes)
void | setSupportedFeatureWeights(QGeoRouteRequest::FeatureWeights featureWeights)
void | setSupportedManeuverDetails(QGeoRouteRequest::ManeuverDetails maneuverDetails)
void | setSupportedRouteOptimizations(QGeoRouteRequest::RouteOptimizations optimizations)
void | setSupportedSegmentDetails(QGeoRouteRequest::SegmentDetails segmentDetails)
void | setSupportedTravelModes(QGeoRouteRequest::TravelModes travelModes)

## Detailed Description

Note: There are no source or binary compatibility guarantees for the backend classes. The API is only guaranteed to work with the Qt version it was developed against. API changes will however only be made in minor releases. (6.6, 6.7, and so on.)

Subclasses of QGeoRoutingManagerEngine need to provide an implementation of calculateRoute().

In the default implementation, supportsRouteUpdates() returns false and updateRoute() returns a QGeoRouteReply object containing a QGeoRouteReply::UnsupportedOptionError.

If the routing service supports updating routes as they are being traveled, the subclass should provide an implementation of updateRoute() and call setSupportsRouteUpdates(true) at some point in time before updateRoute() is called.

The function setSupportsRouteUpdates() is one of several functions which configure the reported capabilities of the engine. If the capabilities of an engine differ from the default values these functions should be used so that the reported capabilities are accurate.

It is important that this is done before calculateRoute(), updateRoute() or any of the capability reporting functions are used to prevent incorrect or inconsistent behavior.

A subclass of QGeoRouteManagerEngine will often make use of a subclass fo QGeoRouteReply internally, in order to add any engine-specific data (such as a QNetworkReply object for network-based services) to the QGeoRouteReply instances used by the engine.

See also QGeoRoutingManager.

## Member Function Documentation

### `[explicit]` QGeoRoutingManagerEngine::QGeoRoutingManagerEngine(const QVariantMap &parameters, QObject *parent = nullptr)

Constructs a new engine with the specified parent, using parameters to pass any implementation specific data to the engine.

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

Destroys this engine.

### `[pure virtual]` QGeoRouteReply *QGeoRoutingManagerEngine::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 engine 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 engine, as reported by the methods in this engine, 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 QGeoRoutingManagerEngine::finished(), QGeoRoutingManagerEngine::errorOccurred(), QGeoRouteReply::finished() or QGeoRouteReply::errorOccurred() with deleteLater().

### `[signal]` void QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::managerName() const

Returns the name which this engine implementation uses to distinguish itself from the implementations provided by other plugins.

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

### int QGeoRoutingManagerEngine::managerVersion() const

Returns the version of this engine implementation.

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

### QLocale::MeasurementSystem QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::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 QGeoRoutingManagerEngine::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().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedFeatureTypes(QGeoRouteRequest::FeatureTypes featureTypes)

Sets the types of features that this engine can take into account during route planning to featureTypes.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no feature types at all.

See also supportedFeatureTypes().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedFeatureWeights(QGeoRouteRequest::FeatureWeights featureWeights)

Sets the weightings which this engine can apply to different features during route planning to featureWeights.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no feature weights at all.

See also supportedFeatureWeights().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedManeuverDetails(QGeoRouteRequest::ManeuverDetails maneuverDetails)

Sets the levels of detail for navigation maneuvers which can be requested by this engine to maneuverDetails.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no maneuver details at all.

See also supportedManeuverDetails().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedRouteOptimizations(QGeoRouteRequest::RouteOptimizations optimizations)

Sets the route optimizations supported by this engine to optimizations.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no route optimizations at all.

See also supportedRouteOptimizations().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedSegmentDetails(QGeoRouteRequest::SegmentDetails segmentDetails)

Sets the levels of detail for routing segments which can be requested by this engine to segmentDetails.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no segment detail at all.

See also supportedSegmentDetails().

### `[protected]` void QGeoRoutingManagerEngine::setSupportedTravelModes(QGeoRouteRequest::TravelModes travelModes)

Sets the travel modes supported by this engine to travelModes.

It is important that subclasses use this method to ensure that the engine reports its capabilities correctly. If this function is not used the engine will report that it supports no travel modes at all.

See also supportedTravelModes().

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

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

See also setSupportedFeatureTypes().

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

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

See also setSupportedFeatureWeights().

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

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

See also setSupportedManeuverDetails().

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

Returns the route optimizations supported by this engine.

See also setSupportedRouteOptimizations().

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

Returns the levels of detail for routing segments which can be requested by this engine.

See also setSupportedSegmentDetails().

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

Returns the travel modes supported by this engine.

See also setSupportedTravelModes().

### `[virtual]` QGeoRouteReply *QGeoRoutingManagerEngine::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 engine 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 enough 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 QGeoRoutingManagerEngine::finished(), QGeoRoutingManagerEngine::errorOccurred(), QGeoRouteReply::finished() or QGeoRouteReply::errorOccurred() with deleteLater().