add late/lazy binding between generic MIDI bindings and controllable elements in the session. this allows you to load a binding map that refers to elements that have not yet been created in the session, and when they are created, the binding will work

git-svn-id: svn://localhost/ardour2/branches/3.0@12921 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 10 insertions, 5 deletions

diff --git a/libs/surfaces/generic_midi/generic_midi_control_protocol.cc b/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
index fab6431c08..6b8e321112 100644
--- a/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
+++ b/libs/surfaces/generic_midi/generic_midi_control_protocol.cc
@@ -773,22 +773,27 @@ GenericMidiControlProtocol::reset_controllables ()
 
 			/* its entirely possible that the session doesn't have
 			 * the specified controllable (e.g. it has too few
-			 * tracks). if we find this to be the case, drop any
-			 * bindings that would be left without controllables.
+			 * tracks). if we find this to be the case, we just leave
+			 * the binding around, unbound, and it will do "late
+			 * binding" (or "lazy binding") if/when any data arrives.
 			 */
 
 			boost::shared_ptr<Controllable> c = session->controllable_by_descriptor (desc);
 			if (c) {
 				existingBinding->set_controllable (c.get());
-			} else {
-				controllables.erase (iter);
-			}
+			} 
 		}
 
 		iter = next;
 	}
 }
 
+boost::shared_ptr<Controllable>
+GenericMidiControlProtocol::lookup_controllable (const ControllableDescriptor& desc) const
+{
+	return session->controllable_by_descriptor (desc);
+}
+
 MIDIFunction*
 GenericMidiControlProtocol::create_function (const XMLNode& node)
 {