Add region polarity invert to Region menu

gtk2_ardour/ardour.menus.in

@@ -385,6 +385,7 @@
         <menuitem action='cut-region-gain'/>
         <menuitem action='reset-region-gain'/>
         <menuitem action='reset-region-gain-envelopes'/>
+        <menuitem action='toggle-region-polarity'/>
         <menuitem action='toggle-region-gain-envelope-active'/>
       </menu>
       <menu action='RegionMenuPosition'>
@@ -931,6 +932,7 @@
       <menuitem action='cut-region-gain'/>
       <menuitem action='reset-region-gain'/>
       <menuitem action='reset-region-gain-envelopes'/>
+      <menuitem action='toggle-region-polarity'/>
       <menuitem action='toggle-region-gain-envelope-active'/>
     </menu>
     <menu action='RegionMenuFades'>

gtk2_ardour/editor.h

@@ -2314,6 +2314,7 @@ private:
 	void set_gain_envelope_visibility ();
 	void set_region_gain_visibility (RegionView*);
 	void toggle_gain_envelope_active ();
+	void toggle_region_polarity ();
 	void reset_region_gain_envelopes ();
 
 	void session_state_saved (std::string);

gtk2_ardour/editor_actions.cc

@@ -1911,6 +1911,8 @@ Editor::register_region_actions ()
 
 	register_toggle_region_action (_region_actions, RegionActionTarget (SelectedRegions|EnteredRegions), "toggle-region-gain-envelope-active", _("Envelope Active"), sigc::mem_fun (*this, &Editor::toggle_gain_envelope_active));
 
+	register_toggle_region_action (_region_actions, RegionActionTarget (SelectedRegions|EnteredRegions), "toggle-region-polarity", _("Invert Polarity"), sigc::mem_fun (*this, &Editor::toggle_region_polarity));
+
 	register_region_action (_region_actions, RegionActionTarget (SelectedRegions|EnteredRegions), "quantize-region", _("Quantize..."), sigc::mem_fun (*this, &Editor::quantize_region));
 	register_region_action (_region_actions, RegionActionTarget (SelectedRegions|EnteredRegions), "legatize-region", _("Legatize"), sigc::bind(sigc::mem_fun (*this, &Editor::legatize_region), false));
 	register_region_action (_region_actions, RegionActionTarget (SelectedRegions|EnteredRegions), "deinterlace-midi", _("Deinterlace Into Layers"), sigc::mem_fun (*this, &Editor::deinterlace_selected_midi_regions));

gtk2_ardour/editor_ops.cc

@@ -6409,6 +6409,41 @@ Editor::set_gain_envelope_visibility ()
 	}
 }
 
+void
+Editor::toggle_region_polarity ()
+{
+	if (_ignore_region_action) {
+		return;
+	}
+
+	RegionSelection rs = get_regions_from_selection_and_entered ();
+
+	if (!_session || rs.empty()) {
+		return;
+	}
+
+	bool in_command = false;
+
+	for (RegionSelection::iterator i = rs.begin(); i != rs.end(); ++i) {
+		AudioRegionView* const arv = dynamic_cast<AudioRegionView*>(*i);
+		if (arv) {
+			arv->region()->clear_changes ();
+			gain_t scale_amplitude = arv->audio_region()->scale_amplitude ();
+			arv->audio_region()->set_scale_amplitude (-1 * scale_amplitude);
+
+			if (!in_command) {
+				begin_reversible_command (_("region polarity invery"));
+				in_command = true;
+			}
+			_session->add_command (new StatefulDiffCommand (arv->region()));
+		}
+	}
+
+	if (in_command) {
+		commit_reversible_command ();
+	}
+}
+
 void
 Editor::toggle_gain_envelope_active ()
 {

gtk2_ardour/editor_selection.cc

@@ -1428,6 +1428,8 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 	bool have_active_fade_in = false;
 	bool have_active_fade_out = false;
 	bool have_transients = false;
+	bool have_inverted_polarity = false;
+	bool have_non_inverted_polarity = false;
 
 	for (list<RegionView*>::const_iterator i = rs.begin(); i != rs.end(); ++i) {
 
@@ -1509,6 +1511,9 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 			} else {
 				have_inactive_fade_out = true;
 			}
+
+			have_inverted_polarity = ar->scale_amplitude () < 0;
+			have_non_inverted_polarity = ar->scale_amplitude () >= 0;
 		}
 	}
 
@@ -1565,6 +1570,10 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 			// Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-gain-envelope-active"))->set_inconsistent ();
 		}
 
+		if (have_inverted_polarity && !have_non_inverted_polarity) {
+			Glib::RefPtr<ToggleAction>::cast_dynamic (_region_actions->get_action("toggle-region-polarity"))->set_active ();
+		}
+
 	} else {
 
 		_region_actions->get_action("loudness-analyze-region")->set_sensitive (false);
@@ -1574,6 +1583,7 @@ Editor::sensitize_the_right_region_actions (bool because_canvas_crossing)
 		_region_actions->get_action("pitch-shift-region")->set_sensitive (false);
 		_region_actions->get_action("strip-region-silence")->set_sensitive (false);
 		_region_actions->get_action("show-rhythm-ferret")->set_sensitive (false);
+		_region_actions->get_action("toggle-region-polarity")->set_sensitive (false);
 
 	}