remove editor/mixer selection change signals; make editor and mixer use PresentationInfo::Change more correctly; make Selection a bit smarter when setting track selection

14 files changed, 181 insertions, 186 deletions

diff --git a/gtk2_ardour/ardour_ui_dependents.cc b/gtk2_ardour/ardour_ui_dependents.cc
index a1c264cf01..4ca4648499 100644
--- a/gtk2_ardour/ardour_ui_dependents.cc
+++ b/gtk2_ardour/ardour_ui_dependents.cc
@@ -101,9 +101,6 @@ ARDOUR_UI::we_have_dependents ()
 
 	ActionManager::load_menus (ARDOUR_COMMAND_LINE::menus_file);
 
-	editor->track_mixer_selection ();
-	mixer->track_editor_selection ();
-
 	/* catch up on parameters */
 
 	boost::function<void (std::string)> pc (boost::bind (&ARDOUR_UI::parameter_changed, this, _1));
diff --git a/gtk2_ardour/editor.cc b/gtk2_ardour/editor.cc
index e64e079808..c9dab0a0e5 100644
--- a/gtk2_ardour/editor.cc
+++ b/gtk2_ardour/editor.cc
@@ -578,7 +578,6 @@ Editor::Editor ()
 	_summary = new EditorSummary (this);
 
 	selection->TimeChanged.connect (sigc::mem_fun(*this, &Editor::time_selection_changed));
-	selection->TracksChanged.connect (sigc::mem_fun(*this, &Editor::track_selection_changed));
 
 	editor_regions_selection_changed_connection = selection->RegionsChanged.connect (sigc::mem_fun(*this, &Editor::region_selection_changed));
 
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index c2a2566873..2cf7f569fb 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -256,7 +256,6 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	Selection& get_selection() const { return *selection; }
 	bool get_selection_extents (framepos_t &start, framepos_t &end) const;  // the time extents of the current selection, whether Range, Region(s), Control Points, or Notes
 	Selection& get_cut_buffer() const { return *cut_buffer; }
-	void track_mixer_selection ();
 
 	bool extend_selection_to_track (TimeAxisView&);
 
diff --git a/gtk2_ardour/editor_mixer.cc b/gtk2_ardour/editor_mixer.cc
index 0c0348383f..51691136ae 100644
--- a/gtk2_ardour/editor_mixer.cc
+++ b/gtk2_ardour/editor_mixer.cc
@@ -285,34 +285,3 @@ Editor::mixer_strip_width_changed ()
 	editor_mixer_strip_width = current_mixer_strip->get_width_enum ();
 }
 
-void
-Editor::track_mixer_selection ()
-{
-	Mixer_UI::instance()->selection().RoutesChanged.connect (sigc::mem_fun (*this, &Editor::follow_mixer_selection));
-}
-
-void
-Editor::follow_mixer_selection ()
-{
-	if (_following_mixer_selection) {
-		return;
-	}
-
-	_following_mixer_selection = true;
-	selection->block_tracks_changed (true);
-
-	AxisViewSelection& s (Mixer_UI::instance()->selection().axes);
-
-	selection->clear_tracks ();
-
-	for (AxisViewSelection::iterator i = s.begin(); i != s.end(); ++i) {
-		TimeAxisView* tav = axis_view_from_stripable ((*i)->stripable());
-		if (tav) {
-			selection->add (tav);
-		}
-	}
-
-	_following_mixer_selection = false;
-	selection->block_tracks_changed (false);
-	selection->TracksChanged (); /* EMIT SIGNAL */
-}
diff --git a/gtk2_ardour/editor_ops.cc b/gtk2_ardour/editor_ops.cc
index ed83da2d80..4df88b9025 100644
--- a/gtk2_ardour/editor_ops.cc
+++ b/gtk2_ardour/editor_ops.cc
@@ -7379,10 +7379,10 @@ edit your ardour.rc file to set the\n\
 		}
 	}
 
-	Mixer_UI::instance()->selection().block_routes_changed (true);
-	selection->block_tracks_changed (true);
 	{
+		PresentationInfo::ChangeSuspender cs;
 		DisplaySuspender ds;
+
 		boost::shared_ptr<RouteList> rl (new RouteList);
 		for (vector<boost::shared_ptr<Route> >::iterator x = routes.begin(); x != routes.end(); ++x) {
 			rl->push_back (*x);
@@ -7393,9 +7393,6 @@ edit your ardour.rc file to set the\n\
 	 * destructors are called,
 	 * diskstream drops references, save_state is called (again for every track)
 	 */
-	selection->block_tracks_changed (false);
-	Mixer_UI::instance()->selection().block_routes_changed (false);
-	selection->TracksChanged (); /* EMIT SIGNAL */
 }
 
 void
diff --git a/gtk2_ardour/editor_routes.cc b/gtk2_ardour/editor_routes.cc
index 27189f29af..016d5432f3 100644
--- a/gtk2_ardour/editor_routes.cc
+++ b/gtk2_ardour/editor_routes.cc
@@ -77,6 +77,7 @@ struct ColumnInfo {
 EditorRoutes::EditorRoutes (Editor* e)
 	: EditorComponent (e)
 	, _ignore_reorder (false)
+	, _ignore_selection_change (false)
 	, _no_redisplay (false)
 	, _adding_routes (false)
 	, _route_deletion_in_progress (false)
@@ -252,7 +253,7 @@ EditorRoutes::EditorRoutes (Editor* e)
 	}
 
 	_display.set_headers_visible (true);
-	_display.get_selection()->set_mode (SELECTION_SINGLE);
+	_display.get_selection()->set_mode (SELECTION_MULTIPLE);
 	_display.get_selection()->set_select_function (sigc::mem_fun (*this, &EditorRoutes::selection_filter));
 	_display.get_selection()->signal_changed().connect (sigc::mem_fun (*this, &EditorRoutes::selection_changed));
 	_display.set_reorderable (true);
@@ -318,7 +319,7 @@ EditorRoutes::EditorRoutes (Editor* e)
 	_display.set_enable_search (false);
 
 	Route::PluginSetup.connect_same_thread (*this, boost::bind (&EditorRoutes::plugin_setup, this, _1, _2, _3));
-	PresentationInfo::Change.connect (*this, MISSING_INVALIDATOR, boost::bind (&EditorRoutes::sync_treeview_from_presentation_info, this), gui_context());
+	PresentationInfo::Change.connect (*this, MISSING_INVALIDATOR, boost::bind (&EditorRoutes::presentation_info_changed, this, _1), gui_context());
 }
 
 bool
@@ -925,7 +926,6 @@ EditorRoutes::route_property_changed (const PropertyChange& what_changed, boost:
 
 			if (what_changed.contains (ARDOUR::Properties::hidden)) {
 				(*i)[_columns.visible] = !stripable->presentation_info().hidden();
-				cerr << stripable->name() << " visibility changed, redisplay\n";
 				redisplay ();
 
 			}
@@ -1093,7 +1093,20 @@ EditorRoutes::sync_presentation_info_from_treeview ()
 }
 
 void
-EditorRoutes::sync_treeview_from_presentation_info ()
+EditorRoutes::presentation_info_changed (PropertyChange const & what_changed)
+{
+	PropertyChange soh;
+	soh.add (Properties::selected);
+	soh.add (Properties::order);
+	soh.add (Properties::hidden);
+
+	if (what_changed.contains (soh)) {
+		sync_treeview_from_presentation_info (what_changed);
+	}
+}
+
+void
+EditorRoutes::sync_treeview_from_presentation_info (PropertyChange const & what_changed)
 {
 	/* Some route order key(s) have been changed, make sure that
 	   we update out tree/list model and GUI to reflect the change.
@@ -1105,53 +1118,85 @@ EditorRoutes::sync_treeview_from_presentation_info ()
 
 	DEBUG_TRACE (DEBUG::OrderKeys, "editor sync model from presentation info.\n");
 
-	vector<int> neworder;
+	PropertyChange hidden_or_order;
+	hidden_or_order.add (Properties::hidden);
+	hidden_or_order.add (Properties::order);
+
 	TreeModel::Children rows = _model->children();
-	uint32_t old_order = 0;
-	bool changed = false;
 
-	if (rows.empty()) {
-		return;
-	}
+	if (what_changed.contains (hidden_or_order)) {
 
-	OrderingKeys sorted;
-	const size_t cmp_max = rows.size ();
+		vector<int> neworder;
+		uint32_t old_order = 0;
+		bool changed = false;
 
-	for (TreeModel::Children::iterator ri = rows.begin(); ri != rows.end(); ++ri, ++old_order) {
-		boost::shared_ptr<Stripable> stripable = (*ri)[_columns.stripable];
-		/* use global order */
-		sorted.push_back (OrderKeys (old_order, stripable, cmp_max));
-	}
+		if (rows.empty()) {
+			return;
+		}
+
+		OrderingKeys sorted;
+		const size_t cmp_max = rows.size ();
+
+		for (TreeModel::Children::iterator ri = rows.begin(); ri != rows.end(); ++ri, ++old_order) {
+			boost::shared_ptr<Stripable> stripable = (*ri)[_columns.stripable];
+			/* use global order */
+			sorted.push_back (OrderKeys (old_order, stripable, cmp_max));
+		}
+
+		SortByNewDisplayOrder cmp;
 
-	SortByNewDisplayOrder cmp;
+		sort (sorted.begin(), sorted.end(), cmp);
+		neworder.assign (sorted.size(), 0);
 
-	sort (sorted.begin(), sorted.end(), cmp);
-	neworder.assign (sorted.size(), 0);
+		uint32_t n = 0;
 
-	uint32_t n = 0;
+		for (OrderingKeys::iterator sr = sorted.begin(); sr != sorted.end(); ++sr, ++n) {
 
-	for (OrderingKeys::iterator sr = sorted.begin(); sr != sorted.end(); ++sr, ++n) {
+			neworder[n] = sr->old_display_order;
 
-		neworder[n] = sr->old_display_order;
+			if (sr->old_display_order != n) {
+				changed = true;
+			}
+		}
 
-		if (sr->old_display_order != n) {
-			changed = true;
+		if (changed) {
+			Unwinder<bool> uw (_ignore_reorder, true);
+			/* prevent traverse_cells: assertion 'row_path != NULL'
+			 * in case of DnD re-order: row-removed + row-inserted.
+			 *
+			 * The rows (stripables) are not actually removed from the model,
+			 * but only from the display in the DnDTreeView.
+			 * ->reorder() will fail to find the row_path.
+			 * (re-order drag -> remove row -> rync PI from TV -> notify -> sync TV from PI -> crash)
+			 */
+			_display.unset_model();
+			_model->reorder (neworder);
+			_display.set_model (_model);
 		}
 	}
 
-	if (changed) {
-		Unwinder<bool> uw (_ignore_reorder, true);
-		/* prevent traverse_cells: assertion 'row_path != NULL'
-		 * in case of DnD re-order: row-removed + row-inserted.
-		 *
-		 * The rows (stripables) are not actually removed from the model,
-		 * but only from the display in the DnDTreeView.
-		 * ->reorder() will fail to find the row_path.
-		 * (re-order drag -> remove row -> rync PI from TV -> notify -> sync TV from PI -> crash)
-		 */
-		_display.unset_model();
-		_model->reorder (neworder);
-		_display.set_model (_model);
+	if (what_changed.contains (Properties::selected)) {
+
+		TrackViewList tvl;
+		PBD::Unwinder<bool> uw (_ignore_selection_change, true);
+
+		/* step one: set the treeview model selection state */
+		for (TreeModel::Children::iterator ri = rows.begin(); ri != rows.end(); ++ri) {
+			boost::shared_ptr<Stripable> stripable = (*ri)[_columns.stripable];
+			if (stripable && stripable->presentation_info().selected()) {
+				TimeAxisView* tav = (*ri)[_columns.tv];
+				if (tav) {
+					tvl.push_back (tav);
+				}
+				_display.get_selection()->select (*ri);
+			} else {
+				_display.get_selection()->unselect (*ri);
+			}
+		}
+
+		/* step two: set the Selection (for stripables/routes) */
+
+		_editor->get_selection().set (tvl);
 	}
 
 	redisplay ();
@@ -1457,6 +1502,10 @@ EditorRoutes::button_press (GdkEventButton* ev)
 void
 EditorRoutes::selection_changed ()
 {
+	if (_ignore_selection_change) {
+		return;
+	}
+
 	_editor->begin_reversible_selection_op (X_("Select Track from Route List"));
 
 	if (_display.get_selection()->count_selected_rows() > 0) {
@@ -1465,8 +1514,6 @@ EditorRoutes::selection_changed ()
 		TreeView::Selection::ListHandle_Path rows = _display.get_selection()->get_selected_rows ();
 		TrackViewList selected;
 
-		_editor->get_selection().clear_regions ();
-
 		for (TreeView::Selection::ListHandle_Path::iterator i = rows.begin(); i != rows.end(); ++i) {
 
 			if ((iter = _model->get_iter (*i))) {
@@ -1545,7 +1592,8 @@ EditorRoutes::initial_display ()
 	}
 
 	_editor->add_stripables (s);
-	sync_treeview_from_presentation_info ();
+
+	sync_treeview_from_presentation_info (Properties::order);
 }
 
 void
diff --git a/gtk2_ardour/editor_routes.h b/gtk2_ardour/editor_routes.h
index 29e8b45dba..e1bf61e82e 100644
--- a/gtk2_ardour/editor_routes.h
+++ b/gtk2_ardour/editor_routes.h
@@ -78,7 +78,8 @@ private:
 	void on_tv_solo_safe_toggled (std::string const &);
 	void build_menu ();
 	void show_menu ();
-	void sync_treeview_from_presentation_info ();
+	void presentation_info_changed (PBD::PropertyChange const &);
+	void sync_treeview_from_presentation_info (PBD::PropertyChange const &);
 	void row_deleted (Gtk::TreeModel::Path const &);
 	void visible_changed (std::string const &);
 	void active_changed (std::string const &);
@@ -165,6 +166,7 @@ private:
 	int _active_column;
 
 	bool _ignore_reorder;
+	bool _ignore_selection_change;
 	bool _no_redisplay;
 	bool _adding_routes;
 	bool _route_deletion_in_progress;
diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index 4ffa753e0c..5192a90abc 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -107,7 +107,6 @@ Mixer_UI::Mixer_UI ()
 	, ignore_reorder (false)
         , _in_group_rebuild_or_clear (false)
         , _route_deletion_in_progress (false)
-	, _following_editor_selection (false)
 	, _maximised (false)
 	, _show_mixer_list (true)
 	, myactions (X_("mixer"))
@@ -116,7 +115,7 @@ Mixer_UI::Mixer_UI ()
 	load_bindings ();
 	_content.set_data ("ardour-bindings", bindings);
 
-	PresentationInfo::Change.connect (*this, invalidator (*this), boost::bind (&Mixer_UI::sync_treeview_from_presentation_info, this), gui_context());
+	PresentationInfo::Change.connect (*this, invalidator (*this), boost::bind (&Mixer_UI::presentation_info_changed, this, _1), gui_context());
 
 	scroller.set_can_default (true);
 	// set_default (scroller);
@@ -384,12 +383,6 @@ Mixer_UI::escape ()
 	select_none ();
 }
 
-void
-Mixer_UI::track_editor_selection ()
-{
-	PublicEditor::instance().get_selection().TracksChanged.connect (sigc::mem_fun (*this, &Mixer_UI::follow_editor_selection));
-}
-
 Gtk::Window*
 Mixer_UI::use_own_window (bool and_fill_it)
 {
@@ -688,6 +681,19 @@ Mixer_UI::remove_strip (MixerStrip* strip)
 }
 
 void
+Mixer_UI::presentation_info_changed (PropertyChange const & what_changed)
+{
+	PropertyChange soh;
+	soh.add (Properties::selected);
+	soh.add (Properties::order);
+	soh.add (Properties::hidden);
+
+	if (what_changed.contains (soh)) {
+		sync_treeview_from_presentation_info (what_changed);
+	}
+}
+
+void
 Mixer_UI::sync_presentation_info_from_treeview ()
 {
 	if (ignore_reorder || !_session || _session->deletion_in_progress()) {
@@ -780,7 +786,7 @@ Mixer_UI::sync_presentation_info_from_treeview ()
 }
 
 void
-Mixer_UI::sync_treeview_from_presentation_info ()
+Mixer_UI::sync_treeview_from_presentation_info (PropertyChange const & what_changed)
 {
 	if (!_session || _session->deletion_in_progress()) {
 		return;
@@ -831,35 +837,21 @@ Mixer_UI::sync_treeview_from_presentation_info ()
 		track_model->reorder (neworder);
 	}
 
-	redisplay_track_list ();
-}
-
-void
-Mixer_UI::follow_editor_selection ()
-{
-	if (_following_editor_selection) {
-		return;
-	}
-
-	_following_editor_selection = true;
-	_selection.block_routes_changed (true);
-
-	TrackSelection& s (PublicEditor::instance().get_selection().tracks);
+	if (what_changed.contains (Properties::selected)) {
 
-	_selection.clear_routes ();
+		PresentationInfo::ChangeSuspender cs;
 
-	for (TrackViewList::iterator i = s.begin(); i != s.end(); ++i) {
-		TimeAxisView* tav = dynamic_cast<TimeAxisView*> (*i);
-		if (tav) {
-			AxisView* axis = axis_by_stripable (tav->stripable());
-			if (axis) {
-				_selection.add (axis);
+		for (list<MixerStrip *>::const_iterator i = strips.begin(); i != strips.end(); ++i) {
+			boost::shared_ptr<Stripable> stripable = (*i)->stripable();
+			if (stripable && stripable->presentation_info().selected()) {
+				_selection.add (*i);
+			} else {
+				_selection.remove (*i);
 			}
 		}
 	}
 
-	_following_editor_selection = false;
-	_selection.block_routes_changed (false);
+	redisplay_track_list ();
 }
 
 
@@ -1537,8 +1529,7 @@ Mixer_UI::initial_track_display ()
 		add_stripables (sl);
 	}
 
-	redisplay_track_list ();
-	sync_treeview_from_presentation_info ();
+	sync_treeview_from_presentation_info (Properties::order);
 }
 
 void
diff --git a/gtk2_ardour/mixer_ui.h b/gtk2_ardour/mixer_ui.h
index 8e5bbddfd0..a96ce69734 100644
--- a/gtk2_ardour/mixer_ui.h
+++ b/gtk2_ardour/mixer_ui.h
@@ -86,7 +86,6 @@ class Mixer_UI : public Gtkmm2ext::Tabbable, public PBD::ScopedConnectionList, p
 	void show_window ();
 
 	void set_session (ARDOUR::Session *);
-	void track_editor_selection ();
 
 	PluginSelector* plugin_selector();
 
@@ -337,8 +336,9 @@ class Mixer_UI : public Gtkmm2ext::Tabbable, public PBD::ScopedConnectionList, p
 
 	Width _strip_width;
 
+	void presentation_info_changed (PBD::PropertyChange const &);
+	void sync_treeview_from_presentation_info (PBD::PropertyChange const &);
 	void sync_presentation_info_from_treeview ();
-	void sync_treeview_from_presentation_info ();
 
 	bool ignore_reorder;
 
@@ -362,9 +362,6 @@ class Mixer_UI : public Gtkmm2ext::Tabbable, public PBD::ScopedConnectionList, p
 
 	friend class MixerGroupTabs;
 
-	void follow_editor_selection ();
-	bool _following_editor_selection;
-
 	void monitor_section_going_away ();
 
 	void monitor_section_attached ();
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index cdae2480ec..64c35e2ecd 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -207,7 +207,6 @@ class PublicEditor : public Gtkmm2ext::Tabbable {
 	virtual Selection& get_selection () const = 0;
 	virtual bool get_selection_extents (framepos_t &start, framepos_t &end) const = 0;
 	virtual Selection& get_cut_buffer () const = 0;
-	virtual void track_mixer_selection () = 0;
 	virtual bool extend_selection_to_track (TimeAxisView&) = 0;
 	virtual void play_selection () = 0;
 	virtual void play_with_preroll () = 0;
diff --git a/gtk2_ardour/route_processor_selection.cc b/gtk2_ardour/route_processor_selection.cc
index 7428267b50..6b7592efd4 100644
--- a/gtk2_ardour/route_processor_selection.cc
+++ b/gtk2_ardour/route_processor_selection.cc
@@ -32,7 +32,7 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-unsigned int RouteProcessorSelection::_no_route_change_signal = 0;
+
 RouteProcessorSelection::RouteProcessorSelection()
 {
 }
@@ -71,14 +71,13 @@ RouteProcessorSelection::clear_processors ()
 void
 RouteProcessorSelection::clear_routes ()
 {
+	PresentationInfo::ChangeSuspender cs;
+
 	for (AxisViewSelection::iterator i = axes.begin(); i != axes.end(); ++i) {
 		(*i)->set_selected (false);
 	}
 	axes.clear ();
 	drop_connections ();
-	if (0 == _no_route_change_signal) {
-		RoutesChanged ();
-	}
 }
 
 void
@@ -109,10 +108,6 @@ RouteProcessorSelection::add (AxisView* r)
 		if (ms) {
 			ms->CatchDeletion.connect (*this, invalidator (*this), boost::bind (&RouteProcessorSelection::remove, this, _1), gui_context());
 		}
-
-		if (0 == _no_route_change_signal) {
-			RoutesChanged();
-		}
 	}
 }
 
@@ -125,9 +120,6 @@ RouteProcessorSelection::remove (AxisView* r)
 	if ((i = find (axes.begin(), axes.end(), r)) != axes.end()) {
 		(*i)->set_selected (false);
 		axes.erase (i);
-		if (0 == _no_route_change_signal) {
-			RoutesChanged ();
-		}
 	}
 }
 
@@ -149,14 +141,3 @@ RouteProcessorSelection::empty ()
 {
 	return processors.empty () && axes.empty ();
 }
-
-void
-RouteProcessorSelection::block_routes_changed (bool yn)
-{
-	if (yn) {
-		++_no_route_change_signal;
-	} else {
-		assert (_no_route_change_signal > 0);
-		--_no_route_change_signal;
-	}
-}
diff --git a/gtk2_ardour/route_processor_selection.h b/gtk2_ardour/route_processor_selection.h
index a4d6f0f1a4..c708723e4d 100644
--- a/gtk2_ardour/route_processor_selection.h
+++ b/gtk2_ardour/route_processor_selection.h
@@ -37,9 +37,6 @@ class RouteProcessorSelection : public PBD::ScopedConnectionList, public sigc::t
 	RouteProcessorSelection& operator= (const RouteProcessorSelection& other);
 
 	sigc::signal<void> ProcessorsChanged;
-	sigc::signal<void> RoutesChanged;
-
-	void block_routes_changed (bool);
 
 	void clear ();
 	bool empty();
@@ -58,8 +55,6 @@ class RouteProcessorSelection : public PBD::ScopedConnectionList, public sigc::t
 
   private:
 	void removed (AxisView*);
-	static unsigned int _no_route_change_signal;
-
 };
 
 bool operator==(const RouteProcessorSelection& a, const RouteProcessorSelection& b);
diff --git a/gtk2_ardour/selection.cc b/gtk2_ardour/selection.cc
index 98b5d62c10..36a4a087a9 100644
--- a/gtk2_ardour/selection.cc
+++ b/gtk2_ardour/selection.cc
@@ -57,7 +57,6 @@ Selection::Selection (const PublicEditor* e)
 	: tracks (e)
 	, editor (e)
 	, next_time_id (0)
-	, _no_tracks_changed (false)
 {
 	clear ();
 
@@ -132,13 +131,13 @@ void
 Selection::clear_tracks (bool with_signal)
 {
 	if (!tracks.empty()) {
+		PresentationInfo::ChangeSuspender cs;
+
 		for (TrackViewList::iterator x = tracks.begin(); x != tracks.end(); ++x) {
 			(*x)->set_selected (false);
 		}
+
 		tracks.clear ();
-		if (!_no_tracks_changed && with_signal) {
-			TracksChanged();
-		}
 	}
 }
 
@@ -290,9 +289,6 @@ Selection::toggle (TimeAxisView* track)
 		tracks.erase (i);
 	}
 
-	if (!_no_tracks_changed) {
-		TracksChanged();
-	}
 }
 
 void
@@ -429,19 +425,18 @@ Selection::add (const list<boost::shared_ptr<Playlist> >& pllist)
 }
 
 void
-Selection::add (const TrackViewList& track_list)
+Selection::add (TrackViewList const & track_list)
 {
 	clear_objects();  //enforce object/range exclusivity
 
+	PresentationInfo::ChangeSuspender cs;
+
 	TrackViewList added = tracks.add (track_list);
 
 	if (!added.empty()) {
 		for (TrackViewList::iterator x = added.begin(); x != added.end(); ++x) {
 			(*x)->set_selected (true);
 		}
-		if (!_no_tracks_changed) {
-			TracksChanged ();
-		}
 	}
 }
 
@@ -639,31 +634,18 @@ Selection::remove (TimeAxisView* track)
 	if ((i = find (tracks.begin(), tracks.end(), track)) != tracks.end()) {
 		track->set_selected (false);
 		tracks.erase (i);
-
-		if (!_no_tracks_changed) {
-			TracksChanged();
-		}
 	}
 }
 
 void
 Selection::remove (const TrackViewList& track_list)
 {
-	bool changed = false;
-
 	for (TrackViewList::const_iterator i = track_list.begin(); i != track_list.end(); ++i) {
 
 		TrackViewList::iterator x = find (tracks.begin(), tracks.end(), *i);
 		if (x != tracks.end()) {
 			(*i)->set_selected (false);
 			tracks.erase (x);
-			changed = true;
-		}
-	}
-
-	if (changed) {
-		if (!_no_tracks_changed) {
-			TracksChanged();
 		}
 	}
 }
@@ -797,7 +779,23 @@ void
 Selection::set (TimeAxisView* track)
 {
 	clear_objects ();  //enforce object/range exclusivity
-	clear_tracks (false);
+
+	PresentationInfo::ChangeSuspender cs;
+
+	if (!tracks.empty()) {
+
+		if (tracks.size() == 1 && tracks.front() == track) {
+			/* already single selection: nothing to do */
+			return;
+		}
+
+		for (TrackViewList::iterator x = tracks.begin(); x != tracks.end(); ++x) {
+			(*x)->set_selected (false);
+		}
+
+		tracks.clear ();
+	}
+
 	add (track);
 }
 
@@ -805,7 +803,40 @@ void
 Selection::set (const TrackViewList& track_list)
 {
 	clear_objects();  //enforce object/range exclusivity
-	clear_tracks (false);
+
+	PresentationInfo::ChangeSuspender cs;
+
+	if (!tracks.empty()) {
+
+		/* cannot use set<T>::operator== (set<T> const &) here, because
+		 * apparently the ordering used within 2 sets is not
+		 * necessarily the same.
+		 */
+
+		if (tracks.size() == track_list.size()) {
+			bool missing = false;
+
+			for (TrackViewList::const_iterator x = track_list.begin(); x != track_list.end(); ++x) {
+				if (find (tracks.begin(), tracks.end(), *x) == tracks.end()) {
+					missing = true;
+				}
+			}
+
+			if (!missing) {
+				/* already same selection: nothing to do */
+				return;
+			}
+		}
+
+		/* argument is different from existing selection */
+
+		for (TrackViewList::iterator x = tracks.begin(); x != tracks.end(); ++x) {
+			(*x)->set_selected (false);
+		}
+
+		tracks.clear ();
+	}
+
 	add (track_list);
 }
 
@@ -1551,9 +1582,3 @@ Selection::remove_regions (TimeAxisView* t)
 		i = tmp;
 	}
 }
-
-void
-Selection::block_tracks_changed (bool yn)
-{
-	_no_tracks_changed = yn;
-}
diff --git a/gtk2_ardour/selection.h b/gtk2_ardour/selection.h
index 8599da70d8..daa81ab1d6 100644
--- a/gtk2_ardour/selection.h
+++ b/gtk2_ardour/selection.h
@@ -95,7 +95,6 @@ class Selection : public sigc::trackable, public PBD::ScopedConnectionList
 	// Selection& operator= (const Selection& other);
 
 	sigc::signal<void> RegionsChanged;
-	sigc::signal<void> TracksChanged;
 	sigc::signal<void> TimeChanged;
 	sigc::signal<void> LinesChanged;
 	sigc::signal<void> PlaylistsChanged;
@@ -104,8 +103,6 @@ class Selection : public sigc::trackable, public PBD::ScopedConnectionList
 	sigc::signal<void> MidiNotesChanged;
 	sigc::signal<void> MidiRegionsChanged;
 
-	void block_tracks_changed (bool);
-
 	void clear ();
 
 	/** check if all selections are empty
@@ -231,7 +228,6 @@ class Selection : public sigc::trackable, public PBD::ScopedConnectionList
   private:
 	PublicEditor const * editor;
 	uint32_t next_time_id;
-	bool _no_tracks_changed;
 };
 
 bool operator==(const Selection& a, const Selection& b);