Pass QObject * (and all its signals) to qml through function (NOT via setContextProperty)

I am trying to implement progress bars like ones in QtCreator (when building or indexing or searching). So, I have QFutureWatcher<something> *Watcher on C++ side and I want to expose all its signals (progressValueChanged(), started(), and so on…) to some qml type, which will react to these signals and display progress on the screen. So, how can I pass Watcher pointer to qml side? Note, I can not use setContextProperty because I must give names to every Watcher! But I even do not know how much Wathcer’s will be created at run-time.