dramatic change in logic and naming for operations related to adding a MIDI region on demand and cloning/unlinking

Existing code would cause data loss due to creation of two Source objects referring the same path, one with removable flags and one without. Careful code review suggested a variety of thinkos, function naming problems and other confusion that caused this. I have tried ot extensively comment what is going on with these operations, because it is one key area in which MIDI differs from audio: with audio, capture is the only way to add a new audio region, but for MIDI there are GUI input events that can add a new region.

1 files changed, 15 insertions, 3 deletions

diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index ba50102ec9..07a32c5bfc 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -49,9 +49,21 @@ class LIBARDOUR_API MidiSource : virtual public Source, public boost::enable_sha
 	MidiSource (Session& session, const XMLNode&);
 	virtual ~MidiSource ();
 
-	boost::shared_ptr<MidiSource> clone (const std::string& path,
-					     Evoral::MusicalTime begin = Evoral::MinMusicalTime,
-	                                     Evoral::MusicalTime end = Evoral::MaxMusicalTime);
+	/** Write the data in the given time range to another MidiSource
+	 * \param newsrc MidiSource to which data will be written. Should be a
+	 *        new, empty source. If it already has contents, the results are
+	 *        undefined. Source must be writable.
+	 *
+	 * \param begin time of earliest event that can be written.
+	 * \param end time of latest event that can be written.
+	 *
+	 * Returns zero on success, non-zero if the write failed for any
+	 * reason.
+	 *
+	 */
+	int write_to (boost::shared_ptr<MidiSource> newsrc,
+		      Evoral::MusicalTime begin = Evoral::MinMusicalTime,
+		      Evoral::MusicalTime end = Evoral::MaxMusicalTime);
 
 	/** Read the data in a given time range from the MIDI source.
 	 * All time stamps in parameters are in audio frames (even if the source has tempo time).