void setObjectVisibility( Handle(HYDROData_Entity) theEntity, const bool theIsVisible );
void setZonesVisible( bool theIsVisible, const bool theLandCover );
void setGeomObjectsVisible( bool theIsVisible );
void setObjectVisibility( Handle(HYDROData_Entity) theEntity, const bool theIsVisible );
void setZonesVisible( bool theIsVisible, const bool theLandCover );
void setGeomObjectsVisible( bool theIsVisible );