Update ControlProtocol API, use CoreSelection

* replace signal-emission with direct calls to CoreSelecton
  using BaseUI's session pointer
* remove unused leftmost strip API
* use CoreSelection for first-selected strip
* Accessing CoreSelection does not modify the session
  (allow access from const callbacks)
* replace static calls in P2 surface

This removes indirection and dependency on the GUI for
managing strip selection.

libs/ardour/ardour/session.h

@@ -317,7 +317,7 @@ public:
 
 	RouteList get_routelist (bool mixer_order = false, PresentationInfo::Flag fl = PresentationInfo::MixerRoutes) const;
 
-	CoreSelection& selection () { return *_selection; }
+	CoreSelection& selection () const { return *_selection; }
 
 	/* because the set of Stripables consists of objects managed
 	 * independently, in multiple containers within the Session (or objects

libs/surfaces/control_protocol/control_protocol.cc

@@ -30,6 +30,7 @@
 #include "ardour/audio_track.h"
 #include "ardour/meter.h"
 #include "ardour/amp.h"
+#include "ardour/selection.h"
 #include "control_protocol/control_protocol.h"
 
 using namespace ARDOUR;
@@ -52,15 +53,6 @@ PBD::Signal0<void> ControlProtocol::VerticalZoomOutSelected;
 PBD::Signal0<void>          ControlProtocol::StepTracksDown;
 PBD::Signal0<void>          ControlProtocol::StepTracksUp;
 
-PBD::Signal1<void,boost::shared_ptr<ARDOUR::Stripable> > ControlProtocol::AddStripableToSelection;
-PBD::Signal1<void,boost::shared_ptr<ARDOUR::Stripable> > ControlProtocol::SetStripableSelection;
-PBD::Signal1<void,boost::shared_ptr<ARDOUR::Stripable> > ControlProtocol::ToggleStripableSelection;
-PBD::Signal1<void,boost::shared_ptr<ARDOUR::Stripable> > ControlProtocol::RemoveStripableFromSelection;
-PBD::Signal0<void>          ControlProtocol::ClearStripableSelection;
-
-Glib::Threads::Mutex ControlProtocol::special_stripable_mutex;
-boost::weak_ptr<Stripable> ControlProtocol::_first_selected_stripable;
-boost::weak_ptr<Stripable> ControlProtocol::_leftmost_mixer_stripable;
 StripableNotificationList ControlProtocol::_last_selected;
 PBD::ScopedConnection ControlProtocol::selection_connection;
 bool ControlProtocol::selection_connected = false;
@@ -345,49 +337,43 @@ ControlProtocol::set_state (XMLNode const & node, int /* version */)
 }
 
 boost::shared_ptr<Stripable>
-ControlProtocol::first_selected_stripable ()
+ControlProtocol::first_selected_stripable () const
 {
-	Glib::Threads::Mutex::Lock lm (special_stripable_mutex);
-	return _first_selected_stripable.lock();
-}
-
-boost::shared_ptr<Stripable>
-ControlProtocol::leftmost_mixer_stripable ()
-{
-	Glib::Threads::Mutex::Lock lm (special_stripable_mutex);
-	return _leftmost_mixer_stripable.lock();
+	return session->selection().first_selected_stripable ();
 }
 
 void
-ControlProtocol::set_leftmost_mixer_stripable (boost::shared_ptr<Stripable> s)
+ControlProtocol::AddStripableToSelection (boost::shared_ptr<ARDOUR::Stripable> s)
 {
-	Glib::Threads::Mutex::Lock lm (special_stripable_mutex);
-	_leftmost_mixer_stripable = s;
+	session->selection().add (s, boost::shared_ptr<AutomationControl>());
 }
 
 void
-ControlProtocol::set_first_selected_stripable (boost::shared_ptr<Stripable> s)
+ControlProtocol::SetStripableSelection (boost::shared_ptr<ARDOUR::Stripable> s)
 {
-	Glib::Threads::Mutex::Lock lm (special_stripable_mutex);
-	_first_selected_stripable = s;
+	session->selection().select_stripable_and_maybe_group (s, true, true, 0);
+}
+
+void
+ControlProtocol::ToggleStripableSelection (boost::shared_ptr<ARDOUR::Stripable> s)
+{
+	session->selection().toggle (s, boost::shared_ptr<AutomationControl>());
+}
+
+void
+ControlProtocol::RemoveStripableFromSelection (boost::shared_ptr<ARDOUR::Stripable> s)
+{
+	session->selection().remove (s, boost::shared_ptr<AutomationControl>());
+}
+
+void
+ControlProtocol::ClearStripableSelection ()
+{
+	session->selection().clear_stripables ();
 }
 
 void
 ControlProtocol::notify_stripable_selection_changed (StripableNotificationListPtr sp)
 {
-	bool had_selection = !_last_selected.empty();
-
 	_last_selected = *sp;
-
-	{
-		Glib::Threads::Mutex::Lock lm (special_stripable_mutex);
-
-		if (!_last_selected.empty()) {
-			if (!had_selection) {
-				_first_selected_stripable = _last_selected.front().lock();
-			}
-		} else {
-			_first_selected_stripable = boost::weak_ptr<Stripable>();
-		}
-	}
 }

libs/surfaces/control_protocol/control_protocol/control_protocol.h

@@ -82,17 +82,13 @@ public:
 	static PBD::Signal0<void> StepTracksDown;
 	static PBD::Signal0<void> StepTracksUp;
 
-	static PBD::Signal1<void, boost::shared_ptr<ARDOUR::Stripable> > AddStripableToSelection;
-	static PBD::Signal1<void, boost::shared_ptr<ARDOUR::Stripable> > SetStripableSelection;
-	static PBD::Signal1<void, boost::shared_ptr<ARDOUR::Stripable> > ToggleStripableSelection;
-	static PBD::Signal1<void, boost::shared_ptr<ARDOUR::Stripable> > RemoveStripableFromSelection;
-	static PBD::Signal0<void> ClearStripableSelection;
+	void AddStripableToSelection (boost::shared_ptr<ARDOUR::Stripable>);
+	void SetStripableSelection (boost::shared_ptr<ARDOUR::Stripable>);
+	void ToggleStripableSelection (boost::shared_ptr<ARDOUR::Stripable>);
+	void RemoveStripableFromSelection (boost::shared_ptr<ARDOUR::Stripable>);
+	void ClearStripableSelection ();
 
-	static boost::shared_ptr<ARDOUR::Stripable> first_selected_stripable ();
-	static void set_first_selected_stripable (boost::shared_ptr<ARDOUR::Stripable>);
-
-	static boost::shared_ptr<ARDOUR::Stripable> leftmost_mixer_stripable ();
-	static void set_leftmost_mixer_stripable (boost::shared_ptr<ARDOUR::Stripable>);
+	boost::shared_ptr<ARDOUR::Stripable> first_selected_stripable () const;
 
 	/* the model here is as follows:
 
@@ -157,9 +153,6 @@ private:
 
 	bool _active;
 
-	static Glib::Threads::Mutex               special_stripable_mutex;
-	static boost::weak_ptr<ARDOUR::Stripable> _leftmost_mixer_stripable;
-	static boost::weak_ptr<ARDOUR::Stripable> _first_selected_stripable;
 	static StripableNotificationList          _last_selected;
 	static PBD::ScopedConnection              selection_connection;
 	static bool                               selection_connected;

libs/surfaces/push2/mix.cc

@@ -40,6 +40,7 @@
 #include "ardour/midiport_manager.h"
 #include "ardour/midi_track.h"
 #include "ardour/midi_port.h"
+#include "ardour/selection.h"
 #include "ardour/session.h"
 #include "ardour/tempo.h"
 #include "ardour/utils.h"
@@ -387,7 +388,7 @@ MixLayout::show_vpot_mode ()
 void
 MixLayout::button_mute ()
 {
-	boost::shared_ptr<Stripable> s = ControlProtocol::first_selected_stripable();
+	boost::shared_ptr<Stripable> s = session.selection().first_selected_stripable();
 	if (s) {
 		boost::shared_ptr<AutomationControl> ac = s->mute_control();
 		if (ac) {
@@ -399,7 +400,7 @@ MixLayout::button_mute ()
 void
 MixLayout::button_solo ()
 {
-	boost::shared_ptr<Stripable> s = ControlProtocol::first_selected_stripable();
+	boost::shared_ptr<Stripable> s = session.selection().first_selected_stripable();
 	if (s) {
 		boost::shared_ptr<AutomationControl> ac = s->solo_control();
 		if (ac) {
@@ -415,7 +416,7 @@ MixLayout::button_lower (uint32_t n)
 		return;
 	}
 
-	ControlProtocol::SetStripableSelection (stripable[n]);
+	session.selection().set (stripable[n], boost::shared_ptr<AutomationControl>());
 }
 
 void
@@ -686,7 +687,7 @@ MixLayout::button_select_release ()
 		/* no visible track selected, select first (if any) */
 
 		if (stripable[0]) {
-			ControlProtocol::SetStripableSelection (stripable[0]);
+			session.selection().set (stripable[0], boost::shared_ptr<AutomationControl>());
 		}
 
 	} else {
@@ -699,10 +700,10 @@ MixLayout::button_select_release ()
 				   switch banks by one, and select leftmost
 				*/
 				if (bank_start != 0) {
-					ControlProtocol::ClearStripableSelection ();
+					session.selection().clear_stripables ();
 					switch_bank (bank_start-1);
 					if (stripable[0]) {
-						ControlProtocol::SetStripableSelection (stripable[0]);
+						session.selection().set (stripable[0], boost::shared_ptr<AutomationControl>());
 					}
 				}
 			} else {
@@ -712,7 +713,7 @@ MixLayout::button_select_release ()
 					--n;
 				}
 				if (n >= 0) {
-					ControlProtocol::SetStripableSelection (stripable[n]);
+					session.selection().set (stripable[n], boost::shared_ptr<AutomationControl>());
 				}
 			}
 
@@ -724,10 +725,10 @@ MixLayout::button_select_release ()
 				/* current selected is rightmost ... cancel selection,
 				   switch banks by one, and select righmost
 				*/
-				ControlProtocol::ToggleStripableSelection (stripable[selected]);
+				session.selection().toggle (stripable[selected], boost::shared_ptr<AutomationControl>());
 				switch_bank (bank_start+1);
 				if (stripable[7]) {
-					ControlProtocol::SetStripableSelection (stripable[7]);
+					session.selection().set (stripable[7], boost::shared_ptr<AutomationControl>());
 				}
 			} else {
 				/* select next, if any */
@@ -737,7 +738,7 @@ MixLayout::button_select_release ()
 				}
 
 				if (n != 8) {
-					ControlProtocol::SetStripableSelection (stripable[n]);
+					session.selection().set (stripable[n], boost::shared_ptr<AutomationControl>());
 				}
 			}
 		}