From 3defa8b521fe350a09bd5a56b96517b62a737476 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <carl@carlh.net>
Date: Sat, 18 Sep 2010 23:31:39 +0000
Subject: [PATCH] Preserve region list selection state even if a region is
 selected which is not shown in the editor.

git-svn-id: svn://localhost/ardour2/branches/3.0@7802 d708f5d6-7413-0410-9779-e7cbd77b26cf
---
 gtk2_ardour/editor.cc           | 2 ++
 gtk2_ardour/editor.h            | 5 +++++
 gtk2_ardour/editor_regions.cc   | 9 +++++++++
 gtk2_ardour/editor_selection.cc | 4 +++-
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index a044f2ad91..9c431fdd2c 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -304,6 +304,8 @@ Editor::Editor ()
 	, _pending_locate_request (false)
 	, _pending_initial_locate (false)
 	, _last_cut_copy_source_track (0)
+
+	, _block_region_list_update_if_empty (false)
 {
 	constructed = false;
 
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 390b94664b..e47946499d 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -2047,6 +2047,11 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	*/
 	TimeAxisView* _last_cut_copy_source_track;
 
+	/** true if the update of the region list's selection from the current Selection
+	    should be blocked if the Selection is empty.  See EditorRegions::selection_changed.
+	*/
+	bool _block_region_list_update_if_empty;
+
 	friend class Drag;
 	friend class RegionDrag;
 	friend class RegionMoveDrag;
diff --git a/gtk2_ardour/editor_regions.cc b/gtk2_ardour/editor_regions.cc
index 9fc2a70663..7034a76af1 100644
--- a/gtk2_ardour/editor_regions.cc
+++ b/gtk2_ardour/editor_regions.cc
@@ -377,6 +377,13 @@ EditorRegions::selection_changed ()
 		return;
 	}
 
+	/* We may have selected a region which is not displayed in the Editor.  If this happens, the
+	   result will be no selected regions in the editor's Selection.  Without the following line,
+	   this `no-selection' will be mapped back to our list, meaning that the selection will
+	   appear not to take.
+	*/
+	_editor->_block_region_list_update_if_empty = true;
+
 	if (_display.get_selection()->count_selected_rows() > 0) {
 
 		TreeIter iter;
@@ -409,6 +416,8 @@ EditorRegions::selection_changed ()
 	} else {
 		_editor->get_selection().clear_regions ();
 	}
+
+	_editor->_block_region_list_update_if_empty = false;
 }
 
 void
diff --git a/gtk2_ardour/editor_selection.cc b/gtk2_ardour/editor_selection.cc
index d17d230cf8..5c0a300322 100644
--- a/gtk2_ardour/editor_selection.cc
+++ b/gtk2_ardour/editor_selection.cc
@@ -957,7 +957,9 @@ Editor::region_selection_changed ()
 	_regions->block_change_connection (true);
 	editor_regions_selection_changed_connection.block(true);
 
-	_regions->unselect_all ();
+	if (!_block_region_list_update_if_empty || !selection->regions.empty()) {
+		_regions->unselect_all ();
+	}
 
 	for (TrackViewList::iterator i = track_views.begin(); i != track_views.end(); ++i) {
 		(*i)->set_selected_regionviews (selection->regions);