- Qt 5.15
- Qt Sensors
- Creating a sensor plugin
- Qt 5.15.2 Reference Documentation

# Creating a sensor plugin

## How a Sensor Plugin is Loaded

Since sensor backends are created on demand, the sensor plugin is loaded and asked to register the sensor backends it handles. The plugin should implement QSensorPluginInterface::registerSensors() and call QSensorManager::registerBackend() to register available backends. Typically the plugin will also inherit from QSensorBackendFactory and implement QSensorBackendFactory::createBackend() in order to instantiate backends it has registered.

The simplest plugin will have just once sensor backend although there is no reason that multiple sensor backends cannot be in a plugin.

An example follows.

     class MyPluginClass : public QObject, public QSensorPluginInterface, public QSensorBackendFactory
     {
         Q_OBJECT
         //Q_PLUGIN_METADATA(IID "com.qt-project.Qt.QSensorPluginInterface/1.0" FILE "plugin.json")
         Q_INTERFACES(QSensorPluginInterface)
     public:
         void registerSensors() override
         {
             QSensorManager::registerBackend(QAccelerometer::type, MyBackend::id, this);
         }

         QSensorBackend *createBackend(QSensor *sensor) override
         {
             if (sensor->identifier() == MyBackend::id)
                 return new MyBackend(sensor);
             return 0;
         }
     };