pv::data::Analog* analog_data =
dynamic_cast<pv::data::Analog*>(data().get());
connect(analog_data, SIGNAL(samples_added(QObject*, uint64_t, uint64_t)),
this, SLOT(on_samples_added()));
pv::data::Analog* analog_data =
dynamic_cast<pv::data::Analog*>(data().get());
connect(analog_data, SIGNAL(samples_added(QObject*, uint64_t, uint64_t)),
this, SLOT(on_samples_added()));