Qt Location GeoServices

Implementing Qt Location GeoService plugins

The Qt Location provides the majority of its functionality through GeoService plugins. This document outlines how to develop a new GeoService plugin.

Plugin Description

Each plugin is described by a json file. The json describes the plugins capabilities and version. Below is an example of a json file used by the OpenStreenMap plugin:

<Code snippet "/tmp/snapshot-qt5full-v5.14.1/qt5/qtbase/../../../plugins/geoservices/osm/osm_plugin.json" not found>

The entries have the following meaning:

Key

Description

Keys

The unique name/key of the plugin. Each GeoService plugin must have a unique name.

Provider

The provider name of the services. Multiple plugins may have the same name. In such cases the Version string will be used to further distinguish the plugins.

Experimental

Marks the service plugin as experimental. API developers may choose to ignore such plugins when instanciating QGeoServiceProvider() .

Version

The plugin version. If multiple plugins have the same provider name, the plugin with the higest version will be used.

Features

List of features provided by the plugin/service. Each feature is a string representation of the corresponding features in QGeoServiceProvider . For more details see routingFeatures() , geocodingFeatures() and placesFeatures() .

Implementing Plugins

A plugin implementer needs to subclass QGeoServiceProviderFactory and as many of the ManagerEngine classes as they want to provide implementations for.

Subclassing QGeoServiceProviderFactory will only involves overriding of one of the following methods:

  • createGeocodingManagerEngine()

  • createRoutingManagerEngine()

  • createPlaceManagerEngine()

If a plugin does not provide an engine the relevant function should return 0.

The QGeoCameraCapabilities class describes the limitations on camera settings imposed by a mapping plugin.

PySide2.QtLocation.QGeoCodingManagerEngine

The QGeoCodingManagerEngine class provides an interface and convenience methods to implementers of QGeoServiceProvider plugins who want to provide support for geocoding operations.

Provides support functionality for map display with QGeoServiceProvider.

PySide2.QtLocation.QGeoRoutingManagerEngine

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

PySide2.QtLocation.QGeoServiceProviderFactory

The QGeoServiceProviderFactory class is a factory class used as the plugin interface for services related to geographical information.

PySide2.QtLocation.QGeoServiceProviderFactoryV2

The QGeoServiceProviderFactoryV2 class is a factory class used as the plugin interface for services related to geographical information.

The QGeoTiledMapReply class manages a tile fetch operation started by an instance of QGeoTiledManagerEngine.

PySide2.QtLocation.QPlaceManagerEngine

The QPlaceManagerEngine class provides an interface for implementers of QGeoServiceProvider plugins who want to provide access to place functionality.