From b0d4f77d928980afdbbefbfd5650712e1b3348ed Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Fri, 7 May 2021 23:15:47 +0200
Subject: [PATCH] Optimize RegionList redisplay for batch changes

---
 gtk2_ardour/editor_regions.cc | 19 ++++++++++++++-----
 gtk2_ardour/editor_regions.h  |  3 +++
 gtk2_ardour/editor_sources.cc | 17 ++++++++++++++---
 gtk2_ardour/editor_sources.h  |  3 +++
 4 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/gtk2_ardour/editor_regions.cc b/gtk2_ardour/editor_regions.cc
index 6bc695bd63..554b071214 100644
--- a/gtk2_ardour/editor_regions.cc
+++ b/gtk2_ardour/editor_regions.cc
@@ -439,6 +439,10 @@ EditorRegions::remove_unused_regions ()
 void
 EditorRegions::regions_changed (boost::shared_ptr<RegionList> rl, const PropertyChange& what_changed)
 {
+	bool freeze = rl->size () > 2;
+	if (freeze) {
+		freeze_tree_model ();
+	}
 	for (RegionList::const_iterator i = rl->begin (); i != rl->end(); ++i) {
 		boost::shared_ptr<Region> r = *i;
 
@@ -474,6 +478,9 @@ EditorRegions::regions_changed (boost::shared_ptr<RegionList> rl, const Property
 			populate_row (r, row, PropertyChange ());
 		}
 	}
+	if (freeze) {
+		thaw_tree_model ();
+	}
 }
 
 void
@@ -534,9 +541,7 @@ EditorRegions::redisplay ()
 	}
 
 	/* store sort column id and type for later */
-	int sort_col_id;
-	Gtk::SortType sort_type;
-	_model->get_sort_column_id (sort_col_id, sort_type);
+	_model->get_sort_column_id (_sort_col_id, _sort_type);
 
 	_display.set_model (Glib::RefPtr<Gtk::TreeStore> (0));
 	_model->clear ();
@@ -547,7 +552,7 @@ EditorRegions::redisplay ()
 
 	RegionFactory::foreach_region (sigc::mem_fun (*this, &EditorRegions::add_region));
 
-	_model->set_sort_column (sort_col_id, sort_type); // re-enabale sorting
+	_model->set_sort_column (_sort_col_id, _sort_type); // re-enabale sorting
 	_display.set_model (_model);
 }
 
@@ -1192,6 +1197,9 @@ EditorRegions::get_single_selection ()
 void
 EditorRegions::freeze_tree_model ()
 {
+	/* store sort column id and type for later */
+	_model->get_sort_column_id (_sort_col_id, _sort_type);
+	_change_connection.block (true);
 	_display.set_model (Glib::RefPtr<Gtk::TreeStore> (0));
 	_model->set_sort_column (-2, SORT_ASCENDING); //Disable sorting to gain performance
 }
@@ -1199,8 +1207,9 @@ EditorRegions::freeze_tree_model ()
 void
 EditorRegions::thaw_tree_model ()
 {
-	_model->set_sort_column (0, SORT_ASCENDING); // renabale sorting
+	_model->set_sort_column (_sort_col_id, _sort_type); // re-enabale sorting
 	_display.set_model (_model);
+	_change_connection.block (false);
 }
 
 void
diff --git a/gtk2_ardour/editor_regions.h b/gtk2_ardour/editor_regions.h
index 4c2f46f49b..b1ef05ec15 100644
--- a/gtk2_ardour/editor_regions.h
+++ b/gtk2_ardour/editor_regions.h
@@ -126,6 +126,9 @@ private:
 
 	sigc::connection _change_connection;
 
+	int           _sort_col_id;
+	Gtk::SortType _sort_type;
+
 	bool selection_filter (const Glib::RefPtr<Gtk::TreeModel>& model, const Gtk::TreeModel::Path& path, bool yn);
 
 	Gtk::Widget* old_focus;
diff --git a/gtk2_ardour/editor_sources.cc b/gtk2_ardour/editor_sources.cc
index b13adc0396..cfe5a303e6 100644
--- a/gtk2_ardour/editor_sources.cc
+++ b/gtk2_ardour/editor_sources.cc
@@ -508,6 +508,10 @@ EditorSources::add_source (boost::shared_ptr<ARDOUR::Region> region)
 void
 EditorSources::regions_changed (boost::shared_ptr<ARDOUR::RegionList> rl, PBD::PropertyChange const &)
 {
+	bool freeze = rl->size () > 2;
+	if (freeze) {
+		freeze_tree_model ();
+	}
 	for (RegionList::const_iterator r = rl->begin (); r != rl->end(); ++r) {
 		boost::shared_ptr<Region> region = *r;
 
@@ -527,6 +531,9 @@ EditorSources::regions_changed (boost::shared_ptr<ARDOUR::RegionList> rl, PBD::P
 			}
 		}
 	}
+	if (freeze) {
+		thaw_tree_model ();
+	}
 }
 
 void
@@ -953,15 +960,19 @@ EditorSources::get_single_selection ()
 void
 EditorSources::freeze_tree_model ()
 {
+	/* store sort column id and type for later */
+	_model->get_sort_column_id (_sort_col_id, _sort_type);
+	_change_connection.block (true);
 	_display.set_model (Glib::RefPtr<Gtk::TreeStore>(0));
 	_model->set_sort_column (-2, SORT_ASCENDING); // Disable sorting to gain performance
 }
 
 void
-EditorSources::thaw_tree_model (){
-
-	_model->set_sort_column (0, SORT_ASCENDING); // renabale sorting
+EditorSources::thaw_tree_model ()
+{
+	_model->set_sort_column (_sort_col_id, _sort_type); // re-enabale sorting
 	_display.set_model (_model);
+	_change_connection.block (false);
 }
 
 XMLNode &
diff --git a/gtk2_ardour/editor_sources.h b/gtk2_ardour/editor_sources.h
index 9923c2f679..2990b88dfd 100644
--- a/gtk2_ardour/editor_sources.h
+++ b/gtk2_ardour/editor_sources.h
@@ -98,6 +98,9 @@ private:
 
 	sigc::connection _change_connection;
 
+	int           _sort_col_id;
+	Gtk::SortType _sort_type;
+
 	Gtk::Widget* old_focus;
 
 	Gtk::CellEditable* tags_editable;