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;
      }
  };