virtual void temporal_zoom_step (bool coarser) = 0;
virtual void scroll_tracks_down_line () = 0;
virtual void scroll_tracks_up_line () = 0;
virtual bool new_regionviews_display_gain () = 0;
virtual void prepare_for_cleanup () = 0;
virtual void temporal_zoom_step (bool coarser) = 0;
virtual void scroll_tracks_down_line () = 0;
virtual void scroll_tracks_up_line () = 0;
virtual bool new_regionviews_display_gain () = 0;
virtual void prepare_for_cleanup () = 0;