From 1faf1a19c6cf686b7dc18fe24aa7101e00aed28b Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Mon, 9 Feb 2015 10:50:54 -0500
Subject: [PATCH] After dragging from multiple tracks to the dropzone, create
 the right number of new tracks.

This does not address the visual flattening that occurs before the drop
is complete. Doing that is complex and there is no immediate solution
visible. The result after the drop is complete is correct, however.
---
 gtk2_ardour/editor_drag.cc | 47 ++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index f736c8b83c..dd2b75f148 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -1036,6 +1036,9 @@ RegionMoveDrag::finished_copy (bool const changed_position, bool const /*changed
 		_editor->begin_reversible_command (Operations::region_copy);
 	}
 
+	typedef map<boost::shared_ptr<Playlist>, RouteTimeAxisView*> PlaylistMapping;
+	PlaylistMapping playlist_mapping;
+
 	/* insert the regions into their new playlists */
 	for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end();) {
 
@@ -1052,13 +1055,23 @@ RegionMoveDrag::finished_copy (bool const changed_position, bool const /*changed
 		} else {
 			where = i->view->region()->position();
 		}
-		
+
 		if (i->time_axis_view < 0) {
-			if (!new_time_axis_view) {
+			/* dragged to drop zone */
+
+			PlaylistMapping::iterator pm;
+			
+			if ((pm = playlist_mapping.find (i->view->region()->playlist())) == playlist_mapping.end()) {
+				/* first region from this original playlist: create a new track */
 				new_time_axis_view = create_destination_time_axis (i->view->region(), i->initial_time_axis_view);
+				playlist_mapping.insert (make_pair (i->view->region()->playlist(), new_time_axis_view));
+				dest_rtv = new_time_axis_view;
+			} else {
+				/* we already created a new track for regions from this playlist, use it */
+				dest_rtv = pm->second;
 			}
-			dest_rtv = new_time_axis_view;
 		} else {
+			/* destination time axis view is the one we dragged to */
 			dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[i->time_axis_view]);
 		}		
 		
@@ -1118,6 +1131,9 @@ RegionMoveDrag::finished_no_copy (
 		_editor->begin_reversible_command (Operations::region_drag);
 	}
 
+	typedef map<boost::shared_ptr<Playlist>, RouteTimeAxisView*> PlaylistMapping;
+	PlaylistMapping playlist_mapping;
+
 	for (list<DraggingView>::const_iterator i = _views.begin(); i != _views.end(); ) {
 
 		RegionView* rv = i->view;
@@ -1129,14 +1145,25 @@ RegionMoveDrag::finished_no_copy (
 		}
 		
 		if (i->time_axis_view < 0) {
-			if (!new_time_axis_view) {
-				new_time_axis_view = create_destination_time_axis (rv->region(), i->initial_time_axis_view);
-			}
-			dest_rtv = new_time_axis_view;
-		} else {
-			dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[i->time_axis_view]);
-		}
+			/* dragged to drop zone */
+
+			PlaylistMapping::iterator pm;
 			
+			if ((pm = playlist_mapping.find (i->view->region()->playlist())) == playlist_mapping.end()) {
+				/* first region from this original playlist: create a new track */
+				new_time_axis_view = create_destination_time_axis (i->view->region(), i->initial_time_axis_view);
+				playlist_mapping.insert (make_pair (i->view->region()->playlist(), new_time_axis_view));
+				dest_rtv = new_time_axis_view;
+			} else {
+				/* we already created a new track for regions from this playlist, use it */
+				dest_rtv = pm->second;
+			}
+			
+		} else {
+			/* destination time axis view is the one we dragged to */
+			dest_rtv = dynamic_cast<RouteTimeAxisView*> (_time_axis_views[i->time_axis_view]);
+		}		
+
 		assert (dest_rtv);
 
 		double const dest_layer = i->layer;