use dynamic_cast instead of qobject_cast, as medianode isn't a qobject (how did this work?)
use dynamic_cast instead of qobject_cast, as medianode isn't a qobject (how did this work?)

sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc