add previous-tab and next-tab actions and bind to PRIMARY-page-up/down by default

gtk2_ardour/ardour.keys.in

@@ -260,6 +260,8 @@ This mode provides many different operations on both regions and control points,
 @trans|Transport/Forward|<@TERTIARY@>Right|fast forward
 @markers|Editor/selected-marker-to-next-region-boundary|<@PRIMARY@><@TERTIARY@>Right|move to next region edge
 
+@wvis|Common/next-tab|<@PRIMARY@>Page_Down|next tab
+@wvis|Common/previous-tab|<@PRIMARY@>Page_Up|previous tab
 @vis|Editor/scroll-tracks-down|Page_Down|scroll down (page)
 @vis|Editor/scroll-tracks-up|Page_Up|scroll up (page)
 @trans|Transport/GotoStart|Home|to start marker

gtk2_ardour/ardour_ui.h

@@ -853,6 +853,9 @@ class ARDOUR_UI : public Gtkmm2ext::UI, public ARDOUR::SessionHandlePtr
 
 	void load_bindings ();
 	bool tabbable_visibility_button_press (GdkEventButton* ev, std::string const& tabbable_name);
+
+	void step_up_through_tabs ();
+	void step_down_through_tabs ();
 };
 
 #endif /* __ardour_gui_h__ */

gtk2_ardour/ardour_ui_dialogs.cc

@@ -373,6 +373,88 @@ ARDOUR_UI::toggle_editor_and_mixer ()
 	}
 }
 
+void
+ARDOUR_UI::step_up_through_tabs ()
+{
+	std::vector<Tabbable*> candidates;
+
+	/* this list must match the order of visibility buttons */
+
+	if (!editor->window_visible()) {
+		candidates.push_back (editor);
+	}
+
+	if (!mixer->window_visible()) {
+		candidates.push_back (mixer);
+	}
+
+	if (!rc_option_editor->window_visible()) {
+		candidates.push_back (rc_option_editor);
+	}
+
+	if (candidates.size() < 2) {
+		/* nothing to be done with zero or one visible in tabs */
+		return;
+	}
+
+	std::vector<Tabbable*>::iterator prev = candidates.end();
+	std::vector<Tabbable*>::iterator i;
+	Gtk::Widget* w = _tabs.get_nth_page (_tabs.get_current_page ());
+
+	for (i = candidates.begin(); i != candidates.end(); ++i) {
+		if (w == &(*i)->contents()) {
+			if (prev != candidates.end()) {
+				_tabs.set_current_page (_tabs.page_num ((*prev)->contents()));
+			} else {
+				_tabs.set_current_page (_tabs.page_num (candidates.back()->contents()));
+			}
+			return;
+		}
+		prev = i;
+	}
+}
+
+void
+ARDOUR_UI::step_down_through_tabs ()
+{
+	std::vector<Tabbable*> candidates;
+
+	/* this list must match the order of visibility buttons */
+
+	if (!editor->window_visible()) {
+		candidates.push_back (editor);
+	}
+
+	if (!mixer->window_visible()) {
+		candidates.push_back (mixer);
+	}
+
+	if (!rc_option_editor->window_visible()) {
+		candidates.push_back (rc_option_editor);
+	}
+
+	if (candidates.size() < 2) {
+		/* nothing to be done with zero or one visible in tabs */
+		return;
+	}
+
+	std::vector<Tabbable*>::reverse_iterator next = candidates.rend();
+	std::vector<Tabbable*>::reverse_iterator i;
+	Gtk::Widget* w = _tabs.get_nth_page (_tabs.get_current_page ());
+
+	for (i = candidates.rbegin(); i != candidates.rend(); ++i) {
+		if (w == &(*i)->contents()) {
+			if (next != candidates.rend()) {
+				_tabs.set_current_page (_tabs.page_num ((*next)->contents()));
+			} else {
+				_tabs.set_current_page (_tabs.page_num (candidates.front()->contents()));
+			}
+			break;
+		}
+		next = i;
+	}
+}
+
 void
 ARDOUR_UI::key_change_tabbable_visibility (Tabbable* t)
 {

gtk2_ardour/ardour_ui_ed.cc

@@ -281,6 +281,9 @@ ARDOUR_UI::install_actions ()
 	global_actions.register_action (common_actions, X_("key-change-mixer-visibility"), _("Change"), sigc::bind (sigc::mem_fun (*this, &ARDOUR_UI::key_change_tabbable_visibility), mixer));
 	global_actions.register_action (common_actions, X_("key-change-preferences-visibility"), _("Change"), sigc::bind (sigc::mem_fun (*this, &ARDOUR_UI::key_change_tabbable_visibility), rc_option_editor));
 
+	global_actions.register_action (common_actions, X_("previous-tab"), _("Previous Tab"), sigc::mem_fun (*this, &ARDOUR_UI::step_up_through_tabs));
+	global_actions.register_action (common_actions, X_("next-tab"), _("Next Tab"), sigc::mem_fun (*this, &ARDOUR_UI::step_down_through_tabs));
+
 	global_actions.register_action (common_actions, X_("toggle-editor-and-mixer"), _("Toggle Editor & Mixer"), sigc::mem_fun (*this, &ARDOUR_UI::toggle_editor_and_mixer));
 
 	/* windows visibility actions */