Changes to Qt Positioning#
Migrate Qt Positioning to Qt 6.
Qt 6 is a result of the conscious effort to make the framework more efficient and easy to use.
We try to maintain binary and source compatibility for all the public APIs in each release. But some changes were inevitable in an effort to make Qt a better framework.
In this topic we summarize those changes in Qt Positioning, and provide guidance to handle them.
Breaking public API changes#
This section contains information about API changes that break source compatibility.
Rename QGeoPolygon::path()#
The QGeoPolygon::path()
and QGeoPolygon::setPath()
methods are renamed to perimeter()
and setPerimeter()
respectively. On the QML side the perimeter
property can be used without any changes.
- Use
- for
bounding area#
The QGeoLocation
class and its Location QML counterpart are updated to use QGeoShape
instead of QGeoRectangle
for a bounding area.
C++#
The QGeoLocation::boundingBox()
and QGeoLocation::setBoundingBox()
are replaced by boundingShape()
and setBoundingShape()
respectively. A QGeoShape
object is now used as an underlying data storage.
QML#
The QGeoLocation::boundingBox
property is replaced by boundingShape
. This property is available since QtPositioning 6.2, so make sure to update the import version in the QML files.
import QtPositioning 6.2
Remove QGeoShape::extendShape()#
The QGeoShape::extendShape()
method was deprecated in Qt 5.9 and finally removed in Qt 6. Use extendRectangle()
and extendCircle()
if you need this functionality for these classes.
Rename signal error to errorOccurred#
In Qt 5 multiple Qt Positioning classes had the error()
signal, which was clashing with the error()
method. In Qt 6 we renamed these signals to errorOccurred()
. Specifically:
QGeoAreaMonitorSource::error()
is renamed toerrorOccurred()
.
QGeoPositionInfoSource::error()
is renamed toerrorOccurred()
.
QGeoSatelliteInfoSource::error()
is renamed toerrorOccurred()
.
Remove update timeout signals#
In Qt 5 QGeoPositionInfoSource::updateTimeout()
and QGeoSatelliteInfoSource::requestTimeout()
signals were used to notify about the cases when the current position or satellite information could not be retrieved within specified timeout. These signals were removed in Qt 6. The errorOccurred()
signals with the new error types are used instead. Specifically:
QGeoPositionInfoSource
uses anerrorOccurred()
signal with a newUpdateTimeoutError
error code.
QGeoSatelliteInfoSource
uses anerrorOccurred()
signal with a newUpdateTimeoutError
error code.
Same changes apply to PositionSource QML object. The PositionSource::updateTimeout()
signal is removed. PositionSource::sourceError property with a PositionSource.UpdateTimeoutError
is used instead.
Redesign NMEA support#
In Qt 5 we had a serialnmea positioning plugin and a nmeaSource
property in PositionSource object.
The plugin provided access to NMEA streams via serial port, while the QML object was responsible for reading NMEA stream from TCP socket or local file.
In Qt 6 we joined all these features in the plugin, which is now renamed to nmea. It is now capable of working with all three NMEA data sources: serial port, TCP socket and local file. See plugin description for more details.
The nmeaSource
property of PositionSource object is now removed.
Other API changes#
This section contains API improvements that do not break source compatibility. However they might have an impact on the application logic, so it is still useful to know about them.
Reset errors properly#
In Qt 5 the errors for QGeoAreaMonitorSource
, QGeoPositionInfoSource
and QGeoSatelliteInfoSource
classes were never reset. This behavior is not logical, as calling startUpdates()
, startMonitoring()
or requestUpdates()
on one of these classes or their subclasses effectively means starting a new work sessions, which means that we should not care about previous errors. Since Qt 6 we reset the error to NoError
once one of the aforementioned methods is called.
- Add
The QGeoAddress
class is extended with streetNumber
property, which holds the information about street number, building name, or anything else that might be used to distinguish one address from another. Use streetNumber()
and setStreetNumber()
to access this property from C++ code.
The street
now holds only the street name.
Same applies to Address QML counterpart. The Address::street property is now used only for street name, while the Address::streetNumber property is used for other important address details.
- Add timeout argument to
update()
The timeout
is specified in milliseconds. If the timeout
is zero (the default value), it defaults to a reasonable timeout period as appropriate for the source.
- Refactor
classes#
These classes now use QExplicitlySharedDataPointer in their implementation. It means that the classes implement copy-on-write. It makes them cheap to copy, so that they can be passed by value.
Another improvement is the addition of support for the efficient move operations.
Changes in Qt Positioning plugin implementation#
This section provides information about the changes in plugin interface.
In Qt 5 for we had two versions of plugin interface:
QGeoPositionInfoSourceFactory
which provided the basic features.
QGeoPositionInfoSourceFactoryV2
which extended the base class with the possibility to provide custom parameters for the created objects.
In Qt 6 we merged these two implementations into one, leaving only the QGeoPositionInfoSourceFactory
class. Its methods now allow to pass custom parameters.
Note
The interface identifier is updated to reflect the major version update. Use "org.qt-project.qt.position.sourcefactory/6.0"
in your Qt Positioning plugins.
Here is an example of plugin class declaration:
class MyPlugin : public QObject, public QGeoPositionInfoSourceFactory { Q_OBJECT Q_PLUGIN_METADATA(IID "org.qt-project.qt.position.sourcefactory/6.0" FILE "plugin.json") Q_INTERFACES(QGeoPositionInfoSourceFactory) public: QGeoPositionInfoSource *positionInfoSource(QObject *parent, const QVariantMap ¶meters) override; QGeoSatelliteInfoSource *satelliteInfoSource(QObject *parent, const QVariantMap ¶meters) override; QGeoAreaMonitorSource *areaMonitor(QObject *parent, const QVariantMap ¶meters) override; };