Support multiple readers for MIDI source/model

Fixes the multiple reader issue #6541 properly without resorting to a
linear search kludge.

All the read state has been pulled out into a MidiCursor which the
caller is required to pass.  The playlist keeps cursors for all the
regions it is reading, any number of cursors are allowed at a time.

MidiCursor should probably be made a smarter and more fool-proof
object (and/or possibly merged with some of the other tracker/fixer
stuff) but for now I wanted to keep it simple.

1 files changed, 2 insertions, 0 deletions

diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 70744429f9..fcf24795db 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -765,6 +765,7 @@ Playlist::flush_notifications (bool from_undo)
 	 notify_region_added (region);
 
 	 region->PropertyChanged.connect_same_thread (region_state_changed_connections, boost::bind (&Playlist::region_changed_proxy, this, _1, boost::weak_ptr<Region> (region)));
+	 region->DropReferences.connect_same_thread (region_drop_references_connections, boost::bind (&Playlist::region_going_away, this, boost::weak_ptr<Region> (region)));
 
 	 return true;
  }
@@ -1745,6 +1746,7 @@ Playlist::region_bounds_changed (const PropertyChange& what_changed, boost::shar
 		 RegionWriteLock rl (this);
 
 		 region_state_changed_connections.drop_connections ();
+		 region_drop_references_connections.drop_connections ();
 
 		 for (RegionList::iterator i = regions.begin(); i != regions.end(); ++i) {
 			 pending_removes.insert (*i);