Re-use the Mixer's PluginManager (singleton)

Previously there were three plugin-manager instances (two of which
were never destroyed).

There were also 3 sets of context-menus (favorites, by tag, by author..),
all of which were re-built when plugin stati changed.

Since the Plugin-manager is a modal dialog, it can be re-used in
all contexts (route-ui, monitor-section, mixer).

gtk2_ardour/monitor_section.cc

@@ -108,7 +108,6 @@ MonitorSection::MonitorSection ()
 
 	channel_size_group = SizeGroup::create (SIZE_GROUP_HORIZONTAL);
 
-	_plugin_selector = new PluginSelector (PluginManager::instance());
 	insert_box = new ProcessorBox (0, boost::bind (&MonitorSection::plugin_selector, this), _rr_selection, 0);
 	insert_box->set_no_show_all ();
 	insert_box->show ();
@@ -587,7 +586,6 @@ void
 MonitorSection::set_session (Session* s)
 {
 	RouteUI::set_session (s);
-	_plugin_selector->set_session (_session);
 	insert_box->set_session (_session);
 
 	Glib::RefPtr<ActionGroup> global_monitor_actions = ActionManager::get_action_group (X_("Monitor Section"));
@@ -1613,6 +1611,12 @@ MonitorSection::processors_changed (ARDOUR::RouteProcessorChange)
 	update_processor_box ();
 }
 
+PluginSelector*
+MonitorSection::plugin_selector ()
+{
+	return Mixer_UI::instance()->plugin_selector ();
+}
+
 void
 MonitorSection::use_others_actions ()
 {

gtk2_ardour/monitor_section.h

@@ -36,7 +36,6 @@
 #include "route_ui.h"
 #include "monitor_selector.h"
 
-#include "plugin_selector.h"
 #include "processor_box.h"
 #include "processor_selection.h"
 
@@ -44,6 +43,8 @@ namespace ArdourWidgets {
 	class TearOff;
 }
 
+class PluginSelector;
+
 class MonitorSection : public RouteUI, public Gtk::EventBox
 {
 public:
@@ -56,7 +57,7 @@ public:
 
 	std::string state_id() const;
 
-	PluginSelector* plugin_selector() { return _plugin_selector; }
+	PluginSelector* plugin_selector();
 
 	void use_others_actions ();
 
@@ -177,7 +178,6 @@ private:
 	void route_property_changed (const PBD::PropertyChange&) {}
 
 	ProcessorBox* insert_box;
-	PluginSelector* _plugin_selector;
 	ProcessorSelection _rr_selection;
 	void help_count_processors (boost::weak_ptr<ARDOUR::Processor> p, uint32_t* cnt) const;
 	uint32_t count_processors ();

gtk2_ardour/route_params_ui.cc

@@ -41,6 +41,7 @@
 #include "gui_thread.h"
 #include "io_selector.h"
 #include "keyboard.h"
+#include "mixer_ui.h"
 #include "mixer_strip.h"
 #include "port_insert_ui.h"
 #include "plugin_selector.h"
@@ -140,7 +141,6 @@ RouteParams_UI::RouteParams_UI ()
 
 	add_events (Gdk::KEY_PRESS_MASK|Gdk::KEY_RELEASE_MASK|Gdk::BUTTON_RELEASE_MASK);
 
-	_plugin_selector = new PluginSelector (PluginManager::instance());
 	show_all();
 }
 
@@ -228,6 +228,11 @@ RouteParams_UI::map_frozen()
 	}
 }
 
+PluginSelector*
+RouteParams_UI::plugin_selector() {
+	return Mixer_UI::instance()->plugin_selector ();
+}
+
 void
 RouteParams_UI::setup_processor_boxes()
 {
@@ -406,7 +411,6 @@ RouteParams_UI::set_session (Session *sess)
 	ArdourWindow::set_session (sess);
 
 	route_display_model->clear();
-	_plugin_selector->set_session (_session);
 
 	if (_session) {
 		boost::shared_ptr<RouteList> r = _session->get_routes();

gtk2_ardour/route_params_ui.h

@@ -64,7 +64,7 @@ public:
 
 	void set_session (ARDOUR::Session*);
 	void session_going_away ();
-	PluginSelector* plugin_selector() { return _plugin_selector; }
+	PluginSelector* plugin_selector();
 
 private:
 	Gtk::VBox                list_vpacker;
@@ -112,7 +112,6 @@ private:
 	IOSelector     * _input_iosel;
 	IOSelector     * _output_iosel;
 
-	PluginSelector    *_plugin_selector;
 	ProcessorSelection  _p_selection;
 
 	boost::shared_ptr<ARDOUR::Route> _route;