Qt Positioning Plugins
Qt Positioning provides the majority of its functionality through plugins. This document outlines how to develop a new position plugin.
Default plugins
Some plugins already ship with Qt. These are:
| android | Wraps Android positioning subsystem. Available only on Android. |
| corelocation | A Core Location backend wraps iOS and macOS positioning subsystems. Available only on Apple platforms supporting corelocation. |
| geoclue | Interfaces with GeoClue v0.12. Requires GeoClue 0.12 to be present to function. |
| geoclue2 | Interfaces with GeoClue v2. Requires GeoClue v2 to be present to function. |
| gypsy | Interfaces with Gypsy daemon. Requires Gypsy to be present to function. |
| winrt | Wraps WinRT positioning subsystem. Available only on WinRT and Windows10. |
| serialnmea | A Serial NMEA backend that parses NMEA streams from a GPS receiver over a serial link to provide position updates. |
| positionpoll | A backend providing only area monitoring functionalities via polling on position updates. |
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 postionpoll plugin:
{
"Keys": ["positionpoll"],
"Provider": "positionpoll",
"Position": false,
"Satellite": false,
"Monitor": true,
"Priority": 1000,
"Testable": true
}
The entries have the following meaning:
| Key | Description |
|---|---|
| Keys | The unique name/key of the plugin. Each position 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. |
| Position | Set to true if the plugin implements a QGeoPositionInfoSource. |
| Satellite | Set to true if the plugin implements a QGeoSatelliteInfoSource. |
| Monitor | Set to true if the plugin implements a QGeoAreaMonitorSource. |
| Priority | The plugin priority. If multiple plugins have the same provider name, the plugin with the higest priority will be used. |
Implementing Plugins
A plugin implementer needs to subclass QGeoPositionInfoSourceFactory and override one or more of its functions. If a plugin does not support a specific feature the function should return 0 or utilize the default implementation.