Fix saving Lua Callbacks when un/register succeeds
[ardour.git] / gtk2_ardour / gain_meter.cc
index baf4193d27fa0466b7bc345e9619f6e036388f3c..41323acf19b46fa0a3e3f9a60780d7b009f0d07e 100644 (file)
 
 #include <limits.h>
 
+#include <pangomm.h>
+
+#include <gtkmm/alignment.h>
+#include <gdkmm/color.h>
+#include <gtkmm/style.h>
+
 #include "ardour/amp.h"
+#include "ardour/logmeter.h"
 #include "ardour/route_group.h"
 #include "ardour/session_route.h"
 #include "ardour/dB.h"
 #include "ardour/utils.h"
 
-#include <pangomm.h>
-#include <gtkmm/style.h>
-#include <gdkmm/color.h>
-#include <gtkmm2ext/utils.h>
-#include <gtkmm2ext/fastmeter.h>
-#include <gtkmm2ext/gtk_ui.h>
+#include "gtkmm2ext/utils.h"
+#include "gtkmm2ext/gtk_ui.h"
+
+#include "widgets/tooltips.h"
+
 #include "pbd/fastlog.h"
 #include "pbd/stacktrace.h"
 
 #include "gain_meter.h"
-#include "logmeter.h"
 #include "gui_thread.h"
 #include "keyboard.h"
 #include "public_editor.h"
 #include "utils.h"
 #include "meter_patterns.h"
 #include "timers.h"
-#include "tooltips.h"
 #include "ui_config.h"
 
 #include "ardour/session.h"
 #include "ardour/midi_track.h"
 #include "ardour/dB.h"
 
-#include "i18n.h"
+#include "pbd/i18n.h"
 
 using namespace ARDOUR;
-using namespace ARDOUR_UI_UTILS;
+using namespace ArdourWidgets;
 using namespace PBD;
 using namespace Gtkmm2ext;
 using namespace Gtk;
@@ -82,14 +86,17 @@ reset_cursor_to_default_state (Gtk::StateType, Gtk::Entry* widget)
        reset_cursor_to_default (widget);
 }
 
+sigc::signal<void, ARDOUR::AutoState> GainMeterBase::ChangeGainAutomationState;
+
 GainMeterBase::GainMeterBase (Session* s, bool horizontal, int fader_length, int fader_girth)
        : gain_adjustment (gain_to_slider_position_with_max (1.0, Config->get_max_gain()),  // value
                           0.0,  // lower
                           1.0,  // upper
                           dB_coeff_step(Config->get_max_gain()) / 10.0,  // step increment
                           dB_coeff_step(Config->get_max_gain()))  // page increment
-       , gain_automation_style_button ("")
        , gain_automation_state_button ("")
+       , meter_point_button (_("pre"))
+       , gain_astate_propagate (false)
        , _data_type (DataType::AUDIO)
 {
        using namespace Menu_Helpers;
@@ -106,8 +113,10 @@ GainMeterBase::GainMeterBase (Session* s, bool horizontal, int fader_length, int
 
        if (horizontal) {
                gain_slider = manage (new HSliderController (&gain_adjustment, boost::shared_ptr<PBD::Controllable>(), fader_length, fader_girth));
+               gain_slider->set_tweaks (ArdourFader::Tweaks(ArdourFader::NoButtonForward | ArdourFader::NoVerticalScroll));
        } else {
                gain_slider = manage (new VSliderController (&gain_adjustment, boost::shared_ptr<PBD::Controllable>(), fader_length, fader_girth));
+               gain_slider->set_tweaks (ArdourFader::NoButtonForward);
        }
 
        level_meter = new LevelMeterHBox(_session);
@@ -116,7 +125,6 @@ GainMeterBase::GainMeterBase (Session* s, bool horizontal, int fader_length, int
        meter_metric_area.signal_button_press_event().connect (sigc::mem_fun (*this, &GainMeterBase::level_meter_button_press));
        meter_metric_area.add_events (Gdk::BUTTON_PRESS_MASK);
 
-       gain_slider->set_tweaks (PixFader::Tweaks(PixFader::NoButtonForward | PixFader::NoVerticalScroll));
        gain_slider->StartGesture.connect (sigc::mem_fun (*this, &GainMeter::amp_start_touch));
        gain_slider->StopGesture.connect (sigc::mem_fun (*this, &GainMeter::amp_stop_touch));
        gain_slider->set_name ("GainFader");
@@ -126,13 +134,13 @@ GainMeterBase::GainMeterBase (Session* s, bool horizontal, int fader_length, int
        gain_display.signal_activate().connect (sigc::mem_fun (*this, &GainMeter::gain_activated));
        gain_display.signal_focus_in_event().connect (sigc::mem_fun (*this, &GainMeter::gain_focused), false);
        gain_display.signal_focus_out_event().connect (sigc::mem_fun (*this, &GainMeter::gain_focused), false);
-       gain_display.set_alignment(0.5);
+       gain_display.set_alignment (0.5);
 
        peak_display.set_name ("MixerStripPeakDisplay");
        set_size_request_to_display_given_text (peak_display, "-80.g", 2, 6); /* note the descender */
        max_peak = minus_infinity();
        peak_display.set_text (_("-inf"));
-       peak_display.set_alignment(0.5);
+       peak_display.set_alignment (0.5);
 
        /* stuff related to the fact that the peak display is not, in
           fact, supposed to be a text entry.
@@ -143,25 +151,48 @@ GainMeterBase::GainMeterBase (Session* s, bool horizontal, int fader_length, int
        peak_display.unset_flags (Gtk::CAN_FOCUS);
        peak_display.set_editable (false);
 
-       gain_automation_style_button.set_name ("mixer strip button");
        gain_automation_state_button.set_name ("mixer strip button");
 
        set_tooltip (gain_automation_state_button, _("Fader automation mode"));
-       set_tooltip (gain_automation_style_button, _("Fader automation type"));
 
-       gain_automation_style_button.unset_flags (Gtk::CAN_FOCUS);
        gain_automation_state_button.unset_flags (Gtk::CAN_FOCUS);
 
        gain_automation_state_button.set_size_request(15, 15);
-       gain_automation_style_button.set_size_request(15, 15);
-
-       gain_astyle_menu.items().push_back (MenuElem (_("Trim")));
-       gain_astyle_menu.items().push_back (MenuElem (_("Abs")));
 
        gain_astate_menu.set_name ("ArdourContextMenu");
-       gain_astyle_menu.set_name ("ArdourContextMenu");
+       gain_astate_menu.set_reserve_toggle_size(false);
+
+       meter_point_button.set_name ("mixer strip button");
+
+       set_tooltip (&meter_point_button, _("Metering point"));
+
+       meter_point_button.unset_flags (Gtk::CAN_FOCUS);
+
+       meter_point_button.set_size_request(15, 15);
+
+       meter_point_menu.set_name ("ArdourContextMenu");
+       meter_point_menu.set_reserve_toggle_size(false);
+
+       meter_point_menu.items().clear ();
+       meter_point_menu.items().push_back (MenuElem(_("Input"),
+        sigc::bind (sigc::mem_fun (*this,
+        &GainMeterBase::meter_point_clicked), (MeterPoint) MeterInput)));
+       meter_point_menu.items().push_back (MenuElem(_("Pre Fader"),
+        sigc::bind (sigc::mem_fun (*this,
+        &GainMeterBase::meter_point_clicked), (MeterPoint) MeterPreFader)));
+       meter_point_menu.items().push_back (MenuElem(_("Post Fader"),
+        sigc::bind (sigc::mem_fun (*this,
+        &GainMeterBase::meter_point_clicked), (MeterPoint) MeterPostFader)));
+       meter_point_menu.items().push_back (MenuElem(_("Output"),
+        sigc::bind (sigc::mem_fun (*this,
+        &GainMeterBase::meter_point_clicked), (MeterPoint) MeterOutput)));
+       meter_point_menu.items().push_back (MenuElem(_("Custom"),
+        sigc::bind (sigc::mem_fun (*this,
+        &GainMeterBase::meter_point_clicked), (MeterPoint) MeterCustom)));
+       meter_point_button.signal_button_press_event().connect (sigc::mem_fun (*this, &GainMeter::meter_press), false);
 
        gain_adjustment.signal_value_changed().connect (sigc::mem_fun(*this, &GainMeterBase::fader_moved));
+       peak_display.signal_button_press_event().connect (sigc::mem_fun(*this, &GainMeterBase::peak_button_press), false);
        peak_display.signal_button_release_event().connect (sigc::mem_fun(*this, &GainMeterBase::peak_button_release), false);
        gain_display.signal_key_press_event().connect (sigc::mem_fun(*this, &GainMeterBase::gain_key_press), false);
 
@@ -225,23 +256,20 @@ GainMeterBase::set_controls (boost::shared_ptr<Route> r,
                gain_astate_menu.items().clear ();
 
                gain_astate_menu.items().push_back (MenuElem (S_("Automation|Manual"),
-                                                             sigc::bind (sigc::mem_fun (*(amp.get()), &Automatable::set_parameter_automation_state),
-                                                                         Evoral::Parameter(GainAutomation), (AutoState) ARDOUR::Off)));
+                                                             sigc::bind (sigc::mem_fun (*this, &GainMeterBase::set_gain_astate), (AutoState) ARDOUR::Off)));
                gain_astate_menu.items().push_back (MenuElem (_("Play"),
-                                                             sigc::bind (sigc::mem_fun (*(amp.get()), &Automatable::set_parameter_automation_state),
-                                                                   Evoral::Parameter(GainAutomation), (AutoState) Play)));
+                                                             sigc::bind (sigc::mem_fun (*this, &GainMeterBase::set_gain_astate), (AutoState) ARDOUR::Play)));
                gain_astate_menu.items().push_back (MenuElem (_("Write"),
-                                                             sigc::bind (sigc::mem_fun (*(amp.get()), &Automatable::set_parameter_automation_state),
-                                                                   Evoral::Parameter(GainAutomation), (AutoState) Write)));
+                                                             sigc::bind (sigc::mem_fun (*this, &GainMeterBase::set_gain_astate), (AutoState) ARDOUR::Write)));
                gain_astate_menu.items().push_back (MenuElem (_("Touch"),
-                                                             sigc::bind (sigc::mem_fun (*(amp.get()), &Automatable::set_parameter_automation_state),
-                                                                   Evoral::Parameter(GainAutomation), (AutoState) Touch)));
+                                                             sigc::bind (sigc::mem_fun (*this, &GainMeterBase::set_gain_astate), (AutoState) ARDOUR::Touch)));
+               gain_astate_menu.items().push_back (MenuElem (_("Latch"),
+                                                             sigc::bind (sigc::mem_fun (*this, &GainMeterBase::set_gain_astate), (AutoState) ARDOUR::Latch)));
 
-               connections.push_back (gain_automation_style_button.signal_button_press_event().connect (sigc::mem_fun(*this, &GainMeterBase::gain_automation_style_button_event), false));
                connections.push_back (gain_automation_state_button.signal_button_press_event().connect (sigc::mem_fun(*this, &GainMeterBase::gain_automation_state_button_event), false));
+               connections.push_back (ChangeGainAutomationState.connect (sigc::mem_fun(*this, &GainMeterBase::set_gain_astate)));
 
                _control->alist()->automation_state_changed.connect (model_connections, invalidator (*this), boost::bind (&GainMeter::gain_automation_state_changed, this), gui_context());
-               _control->alist()->automation_style_changed.connect (model_connections, invalidator (*this), boost::bind (&GainMeter::gain_automation_style_changed, this), gui_context());
 
                gain_automation_state_changed ();
        }
@@ -259,6 +287,22 @@ GainMeterBase::set_controls (boost::shared_ptr<Route> r,
        }
 }
 
+void
+GainMeterBase::set_gain_astate (AutoState as)
+{
+       if (gain_astate_propagate) {
+               gain_astate_propagate = false;
+               ChangeGainAutomationState (as);
+               return;
+       }
+       if (_amp) {
+               _amp->set_parameter_automation_state (Evoral::Parameter (GainAutomation), as);
+       } else if (_control) {
+               _control->set_automation_state (as);
+               _session->set_dirty ();
+       }
+}
+
 void
 GainMeterBase::setup_gain_adjustment ()
 {
@@ -278,7 +322,7 @@ GainMeterBase::setup_gain_adjustment ()
                gain_adjustment.set_upper (GAIN_COEFF_UNITY);
                gain_adjustment.set_step_increment (dB_coeff_step(Config->get_max_gain()) / 10.0);
                gain_adjustment.set_page_increment (dB_coeff_step(Config->get_max_gain()));
-               gain_slider->set_default_value (gain_to_slider_position (GAIN_COEFF_UNITY));
+               gain_slider->set_default_value (gain_to_slider_position_with_max (GAIN_COEFF_UNITY, Config->get_max_gain()));
        } else {
                _data_type = DataType::MIDI;
                gain_adjustment.set_lower (0.0);
@@ -342,7 +386,7 @@ GainMeterBase::setup_meters (int len)
 void
 GainMeterBase::set_type (MeterType t)
 {
-       level_meter->set_type(t);
+       level_meter->set_meter_type(t);
 }
 
 void
@@ -376,7 +420,7 @@ GainMeter::set_type (MeterType t)
 bool
 GainMeterBase::gain_key_press (GdkEventKey* ev)
 {
-       if (key_is_legal_for_numeric_entry (ev->keyval)) {
+       if (ARDOUR_UI_UTILS::key_is_legal_for_numeric_entry (ev->keyval)) {
                /* drop through to normal handling */
                return false;
        }
@@ -384,6 +428,12 @@ GainMeterBase::gain_key_press (GdkEventKey* ev)
        return true;
 }
 
+bool
+GainMeterBase::peak_button_press (GdkEventButton* ev)
+{
+       return true;
+}
+
 bool
 GainMeterBase::peak_button_release (GdkEventButton* ev)
 {
@@ -405,9 +455,13 @@ GainMeterBase::peak_button_release (GdkEventButton* ev)
 void
 GainMeterBase::reset_peak_display ()
 {
+       if (!_route) {
+               // catch "reset all" for VCAs
+               return;
+       }
        _meter->reset_max();
        level_meter->clear_meters();
-       max_peak = -INFINITY;
+       max_peak = minus_infinity ();
        peak_display.set_text (_("-inf"));
        peak_display.set_name ("MixerStripPeakDisplay");
 }
@@ -465,15 +519,9 @@ GainMeterBase::gain_activated ()
 {
        float f;
 
-       {
-               // Switch to user's preferred locale so that
-               // if they use different LC_NUMERIC conventions,
-               // we will honor them.
-
-               PBD::LocaleGuard lg;
-               if (sscanf (gain_display.get_text().c_str(), "%f", &f) != 1) {
-                       return;
-               }
+       // Use the user's preferred locale/LC_NUMERIC setting
+       if (sscanf (gain_display.get_text().c_str(), "%f", &f) != 1) {
+               return;
        }
 
        /* clamp to displayable values */
@@ -541,7 +589,14 @@ GainMeterBase::fader_moved ()
                        value = gain_adjustment.get_value();
                }
 
-               _control->set_value (value, Controllable::UseGroup);
+               // XXX hack allow to override group
+               // (this breaks group'ed  shift+click reset)
+               if (Keyboard::the_keyboard().key_is_down (GDK_Shift_R)
+                               || Keyboard::the_keyboard().key_is_down (GDK_Shift_L)) {
+                       _control->set_value (value, Controllable::InverseGroup);
+               } else {
+                       _control->set_value (value, Controllable::UseGroup);
+               }
        }
 
        show_gain ();
@@ -574,7 +629,8 @@ GainMeterBase::effective_gain_display ()
 void
 GainMeterBase::gain_changed ()
 {
-       Gtkmm2ext::UI::instance()->call_slot (invalidator (*this), boost::bind (&GainMeterBase::effective_gain_display, this));
+       ENSURE_GUI_THREAD (*this, &GainMeterBase::gain_automation_state_changed);
+       effective_gain_display ();
 }
 
 void
@@ -598,114 +654,44 @@ void
 GainMeterBase::update_gain_sensitive ()
 {
        bool x = !(_control->alist()->automation_state() & Play);
-       static_cast<Gtkmm2ext::SliderController*>(gain_slider)->set_sensitive (x);
-}
-
-static MeterPoint
-next_meter_point (MeterPoint mp)
-{
-       switch (mp) {
-       case MeterInput:
-               return MeterPreFader;
-               break;
-
-       case MeterPreFader:
-               return MeterPostFader;
-               break;
-
-       case MeterPostFader:
-               return MeterOutput;
-               break;
-
-       case MeterOutput:
-               return MeterCustom;
-               break;
-
-       case MeterCustom:
-               return MeterInput;
-               break;
-       }
-
-       abort(); /*NOTREACHED*/
-       return MeterInput;
+       static_cast<ArdourWidgets::SliderController*>(gain_slider)->set_sensitive (x);
 }
 
 gint
 GainMeterBase::meter_press(GdkEventButton* ev)
 {
-       wait_for_release = false;
-
        if (!_route) {
-               return FALSE;
+               return false;
        }
-
        if (!ignore_toggle) {
-
-               if (Keyboard::is_context_menu_event (ev)) {
-
-                       // no menu at this time.
-
-               } else {
-
-                       if (Keyboard::is_button2_event(ev)) {
-
-                               // Primary-button2 click is the midi binding click
-                               // button2-click is "momentary"
-
-                               if (!Keyboard::modifier_state_equals (ev->state, Keyboard::ModifierMask (Keyboard::PrimaryModifier))) {
-                                       wait_for_release = true;
-                                       old_meter_point = _route->meter_point ();
-                               }
-                       }
-
-                       if (_route && (ev->button == 1 || Keyboard::is_button2_event (ev))) {
-
+               switch (ev->button) {
+                       case 1:
                                if (Keyboard::modifier_state_equals (ev->state, Keyboard::ModifierMask (Keyboard::PrimaryModifier|Keyboard::TertiaryModifier))) {
 
                                        /* Primary+Tertiary-click applies change to all routes */
 
-                                       _session->foreach_route (this, &GainMeterBase::set_meter_point, next_meter_point (_route->meter_point()));
-
+                                       meter_point_change_target = MeterPointChangeAll;
 
                                } else if (Keyboard::modifier_state_equals (ev->state, Keyboard::PrimaryModifier)) {
 
-                                       /* Primary-click: solo mix group.
-                                          NOTE: Primary-button2 is MIDI learn.
-                                       */
+                                       /* Primary-click: apply change to all routes in group */
 
-                                       if (ev->button == 1) {
-                                               set_route_group_meter_point (*_route, next_meter_point (_route->meter_point()));
-                                       }
+                                       meter_point_change_target = MeterPointChangeGroup;
 
                                } else {
 
                                        /* click: change just this route */
 
-                                       // XXX no undo yet
-
-                                       _route->set_meter_point (next_meter_point (_route->meter_point()));
+                                       meter_point_change_target = MeterPointChangeSingle;
                                }
-                       }
-               }
-       }
-
-       return true;
-
-}
-
-gint
-GainMeterBase::meter_release(GdkEventButton*)
-{
-       if (!ignore_toggle) {
-               if (wait_for_release) {
-                       wait_for_release = false;
-
-                       if (_route) {
-                               set_meter_point (*_route, old_meter_point);
-                       }
+                               Gtkmm2ext::anchored_menu_popup(&meter_point_menu,
+                                                            &meter_point_button,
+                                                          "", 1, ev->time);
+                               break;
+                       default:
+                               break;
                }
        }
-
        return true;
 }
 
@@ -728,23 +714,34 @@ GainMeterBase::set_route_group_meter_point (Route& route, MeterPoint mp)
 }
 
 void
-GainMeterBase::meter_point_clicked ()
+GainMeterBase::meter_point_clicked (MeterPoint mp)
 {
        if (_route) {
-               /* WHAT? */
+               switch (meter_point_change_target) {
+                       case MeterPointChangeAll:
+                               _session->foreach_route (this, &GainMeterBase::set_meter_point, mp);
+                               break;
+                       case MeterPointChangeGroup:
+                               set_route_group_meter_point (*_route, mp);
+                               break;
+                       case MeterPointChangeSingle:
+                               _route->set_meter_point (mp);
+                               break;
+               }
        }
 }
 
 void
 GainMeterBase::amp_start_touch ()
 {
-       _control->start_touch (_control->session().transport_frame());
+       _control->start_touch (_control->session().transport_sample());
 }
 
 void
 GainMeterBase::amp_stop_touch ()
 {
-       _control->stop_touch (false, _control->session().transport_frame());
+       _control->stop_touch (_control->session().transport_sample());
+       effective_gain_display ();
 }
 
 gint
@@ -756,7 +753,10 @@ GainMeterBase::gain_automation_state_button_event (GdkEventButton *ev)
 
        switch (ev->button) {
                case 1:
-                       gain_astate_menu.popup (1, ev->time);
+                       gain_astate_propagate = Keyboard::modifier_state_contains (ev->state, Keyboard::ModifierMask (Keyboard::PrimaryModifier | Keyboard::TertiaryModifier));
+                       Gtkmm2ext::anchored_menu_popup(&gain_astate_menu,
+                                                      &gain_automation_state_button,
+                                                      "", 1, ev->time);
                        break;
                default:
                        break;
@@ -765,22 +765,6 @@ GainMeterBase::gain_automation_state_button_event (GdkEventButton *ev)
        return TRUE;
 }
 
-gint
-GainMeterBase::gain_automation_style_button_event (GdkEventButton *ev)
-{
-       if (ev->type == GDK_BUTTON_RELEASE) {
-               return TRUE;
-       }
-
-       switch (ev->button) {
-       case 1:
-               gain_astyle_menu.popup (1, ev->time);
-               break;
-       default:
-               break;
-       }
-       return TRUE;
-}
 
 string
 GainMeterBase::astate_string (AutoState state)
@@ -801,59 +785,25 @@ GainMeterBase::_astate_string (AutoState state, bool shrt)
 
        switch (state) {
        case ARDOUR::Off:
-               sstr = (shrt ? "M" : _("M"));
+               sstr = (shrt ? "M" : S_("Manual|M"));
                break;
        case Play:
-               sstr = (shrt ? "P" : _("P"));
+               sstr = (shrt ? "P" : S_("Play|P"));
                break;
        case Touch:
-               sstr = (shrt ? "T" : _("T"));
+               sstr = (shrt ? "T" : S_("Trim|T"));
+               break;
+       case Latch:
+               sstr = (shrt ? "L" : S_("Latch|L"));
                break;
        case Write:
-               sstr = (shrt ? "W" : _("W"));
+               sstr = (shrt ? "W" : S_("Write|W"));
                break;
        }
 
        return sstr;
 }
 
-string
-GainMeterBase::astyle_string (AutoStyle style)
-{
-       return _astyle_string (style, false);
-}
-
-string
-GainMeterBase::short_astyle_string (AutoStyle style)
-{
-       return _astyle_string (style, true);
-}
-
-string
-GainMeterBase::_astyle_string (AutoStyle style, bool shrt)
-{
-       if (style & Trim) {
-               return _("Trim");
-       } else {
-               /* XXX it might different in different languages */
-
-               return (shrt ? _("Abs") : _("Abs"));
-       }
-}
-
-void
-GainMeterBase::gain_automation_style_changed ()
-{
-       switch (_width) {
-       case Wide:
-               gain_automation_style_button.set_text (astyle_string(_control->alist()->automation_style()));
-               break;
-       case Narrow:
-               gain_automation_style_button.set_text  (short_astyle_string(_control->alist()->automation_style()));
-               break;
-       }
-}
-
 void
 GainMeterBase::gain_automation_state_changed ()
 {
@@ -879,14 +829,6 @@ GainMeterBase::gain_automation_state_changed ()
        update_gain_sensitive ();
 
        gain_watching.disconnect();
-
-       if (automation_watch_required) {
-               /* start watching automation so that things move */
-               gain_watching = Timers::rapid_connect (sigc::mem_fun (*this, &GainMeterBase::effective_gain_display));
-       } else {
-               /* update once to get the correct value shown as we re-enter off/manual mode */
-               effective_gain_display();
-       }
 }
 
 const ChanCount
@@ -965,17 +907,13 @@ GainMeter::GainMeter (Session* s, int fader_length)
        meter_metric_area.set_name ("AudioTrackMetrics");
        meter_metric_area.set_size_request(PX_SCALE(24, 24), -1);
 
-       gain_automation_style_button.set_name ("mixer strip button");
        gain_automation_state_button.set_name ("mixer strip button");
 
        set_tooltip (gain_automation_state_button, _("Fader automation mode"));
-       set_tooltip (gain_automation_style_button, _("Fader automation type"));
 
-       gain_automation_style_button.unset_flags (Gtk::CAN_FOCUS);
        gain_automation_state_button.unset_flags (Gtk::CAN_FOCUS);
 
        gain_automation_state_button.set_size_request (PX_SCALE(12, 15), PX_SCALE(12, 15));
-       gain_automation_style_button.set_size_request (PX_SCALE(12, 15), PX_SCALE(12, 15));
 
        fader_vbox.set_spacing (0);
        fader_vbox.pack_start (*gain_slider, true, true);