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, 56 insertions, 0 deletions

diff --git a/libs/ardour/ardour/midi_cursor.h b/libs/ardour/ardour/midi_cursor.h
new file mode 100644
index 0000000000..5cb89c87f5
--- /dev/null
+++ b/libs/ardour/ardour/midi_cursor.h
@@ -0,0 +1,56 @@
+/*
+    Copyright (C) 2016 Paul Davis
+    Author: David Robillard
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __ardour_midi_cursor_h__
+#define __ardour_midi_cursor_h__
+
+#include <set>
+
+#include <boost/utility.hpp>
+
+#include "ardour/types.h"
+#include "evoral/Beats.hpp"
+#include "evoral/Sequence.hpp"
+#include "pbd/signals.h"
+
+namespace ARDOUR {
+
+struct MidiCursor : public boost::noncopyable {
+	MidiCursor() : last_read_end(0) {}
+
+	void connect(PBD::Signal1<void, bool>& invalidated) {
+		connections.drop_connections();
+		invalidated.connect_same_thread(
+			connections, boost::bind(&MidiCursor::invalidate, this, _1));
+	}
+
+	void invalidate(bool preserve_notes) {
+		iter.invalidate(preserve_notes ? &active_notes : NULL);
+		last_read_end = 0;
+	}
+
+	Evoral::Sequence<Evoral::Beats>::const_iterator        iter;
+	std::set<Evoral::Sequence<Evoral::Beats>::WeakNotePtr> active_notes;
+	framepos_t                                             last_read_end;
+	PBD::ScopedConnectionList                              connections;
+};
+
+}
+
+#endif /* __ardour_midi_cursor_h__ */