add syntax and scaffolding for MIDI binding maps to refer to selected tracks/busses.

THIS DOES NOT WORK YET. Selection information is not available in libardour at this time

libs/ardour/ardour/session.h

@@ -279,6 +279,7 @@ class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::Scop
 	boost::shared_ptr<Route> route_by_name (std::string);
 	boost::shared_ptr<Route> route_by_id (PBD::ID);
 	boost::shared_ptr<Route> route_by_remote_id (uint32_t id);
+	boost::shared_ptr<Route> route_by_selected_count (uint32_t cnt);
 	boost::shared_ptr<Track> track_by_diskstream_id (PBD::ID);
 	void routes_using_input_from (const std::string& str, RouteList& rl);
 

libs/ardour/session.cc

@@ -4061,6 +4061,19 @@ Session::route_by_remote_id (uint32_t id)
 }
 
 
+boost::shared_ptr<Route>
+Session::route_by_selected_count (uint32_t id)
+{
+	boost::shared_ptr<RouteList> r = routes.reader ();
+
+	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+		/* NOT IMPLEMENTED */
+	}
+
+	return boost::shared_ptr<Route> ((Route*) 0);
+}
+
+
 void
 Session::reassign_track_numbers ()
 {

libs/ardour/session_state.cc

@@ -3339,6 +3339,10 @@ Session::controllable_by_descriptor (const ControllableDescriptor& desc)
 	case ControllableDescriptor::RemoteControlID:
 		r = route_by_remote_id (desc.rid());
 		break;
+
+	case ControllableDescriptor::SelectionCount:
+		r = route_by_selected_count (desc.selection_id());
+		break;
 	}
 
 	if (!r) {

libs/pbd/controllable_descriptor.cc

@@ -56,6 +56,10 @@ ControllableDescriptor::set (const std::string& str)
 		if (rest[0][0] == 'B') {
 			_banked = true;
 			_rid = atoi (rest[0].substr (1));
+		} else if (rest[0][0] == 'S') {
+			_top_level_type = SelectionCount;
+			_banked = true;
+			_selection_id = atoi (rest[0].substr (1));
 		} else if (isdigit (rest[0][0])) {
 			_banked = false;
 			_rid = atoi (rest[0]);
@@ -123,7 +127,7 @@ ControllableDescriptor::set (const std::string& str)
 }
 
 uint32_t
-ControllableDescriptor::rid() const
+ControllableDescriptor::rid () const
 {
 	if (banked()) {
 		return _rid + _bank_offset;
@@ -132,6 +136,16 @@ ControllableDescriptor::rid() const
 	return _rid;
 }
 
+uint32_t
+ControllableDescriptor::selection_id () const
+{
+	if (banked()) {
+		return _selection_id + _bank_offset;
+	}
+
+	return _selection_id;
+}
+
 uint32_t
 ControllableDescriptor::target (uint32_t n) const
 {

libs/pbd/pbd/controllable_descriptor.h

@@ -31,7 +31,8 @@ class LIBPBD_API ControllableDescriptor {
 public:
     enum TopLevelType {
 	    RemoteControlID,
-	    NamedRoute
+	    NamedRoute,
+	    SelectionCount,
     };
 
     enum SubType {
@@ -68,6 +69,7 @@ public:
     SubType subtype() const { return _subtype; }
 
     uint32_t rid() const;
+    uint32_t selection_id() const;
     uint32_t target (uint32_t n) const;
     bool banked() const { return _banked; }
 
@@ -77,7 +79,10 @@ private:
     TopLevelType          _top_level_type;
     SubType               _subtype;
     std::string           _top_level_name;
-    uint32_t              _rid;
+    union {
+	    uint32_t  _rid;
+	    uint32_t  _selection_id;
+    };
     std::vector<uint32_t> _target;
     uint32_t              _banked;
     uint32_t              _bank_offset;