Gtkmm2ext::SliderController *gain_slider;
Gtk::Adjustment gain_adjustment;
Gtkmm2ext::FocusEntry gain_display;
Gtkmm2ext::SliderController *gain_slider;
Gtk::Adjustment gain_adjustment;
Gtkmm2ext::FocusEntry gain_display;
Gtk::DrawingArea meter_metric_area;
Gtk::DrawingArea meter_ticks1_area;
Gtk::DrawingArea meter_ticks2_area;
Gtk::DrawingArea meter_metric_area;
Gtk::DrawingArea meter_ticks1_area;
Gtk::DrawingArea meter_ticks2_area;