Allow removing multiple control points

It was surprising that removing on multiple selected control points only
removed one of them.

This allows selecting multiple points by dragging a box or
Ctrl-clicking, then removing all from the context menu of one of the
points.

Some more trivial implementations of this suffered from problems when
deletion of control points in the model also invalidated the iterator
over selected control points.

Author: kiilerix

Diff for: gtk2_ardour/automation_line.cc

@@ -926,13 +926,21 @@ AutomationLine::is_first_point (ControlPoint& cp)
 
 // This is copied into AudioRegionGainLine
 void
-AutomationLine::remove_point (ControlPoint& cp)
+AutomationLine::remove_points (std::vector<ControlPoint*> const& cps)
 {
 	trackview.editor().begin_reversible_command (_("remove control point"));
 	XMLNode &before = alist->get_state();
 
 	trackview.editor ().get_selection ().clear_points ();
-	alist->erase (cp.model());
+
+	// Extract models before the ControlPoints iterator mutates on ControlPoint deletion
+	std::list<Evoral::ControlList::iterator> models;
+	for (auto const & cp : cps) {
+		models.push_back(cp->model());
+	}
+	for (auto const & model : models) {
+		alist->erase (model);
+	}
 
 	trackview.editor().session()->add_command(
 		new MementoCommand<AutomationList> (memento_command_binder (), &before, &alist->get_state()));

Diff for: gtk2_ardour/automation_line.h

@@ -85,7 +85,6 @@ class AutomationLine : public sigc::trackable, public PBD::StatefulDestructible
 	void get_selectables (Temporal::timepos_t const &, Temporal::timepos_t const &, double, double, std::list<Selectable*>&);
 	void get_inverted_selectables (Selection&, std::list<Selectable*>& results);
 
-	virtual void remove_point (ControlPoint&);
 	bool control_points_adjacent (double xval, uint32_t& before, uint32_t& after);
 
 	/* dragging API */
@@ -150,6 +149,7 @@ class AutomationLine : public sigc::trackable, public PBD::StatefulDestructible
 	void set_colors();
 
 	void modify_points_y (std::vector<ControlPoint*> const&, double);
+	virtual void remove_points (std::vector<ControlPoint*> const& cps);
 
 	virtual MementoCommandBinder<ARDOUR::AutomationList>* memento_command_binder ();
 

Diff for: gtk2_ardour/editor_mouse.cc

@@ -2476,11 +2476,15 @@ Editor::remove_control_point (ArdourCanvas::Item* item)
 		abort(); /*NOTREACHED*/
 	}
 
-	if (!can_remove_control_point (*control_point)) {
-		return;
+	std::vector<ControlPoint*> cps;
+
+	for (auto const& cp : selection->points) {
+		if ((&cp->line() == &control_point->line ()) && can_remove_control_point (*cp)) {
+			cps.push_back (cp);
+		}
 	}
 
-	control_point->line().remove_point (*control_point);
+	control_point->line().remove_points (cps);
 }
 
 void

Diff for: gtk2_ardour/region_gain_line.cc

@@ -79,7 +79,7 @@ AudioRegionGainLine::start_drag_single (ControlPoint* cp, double x, float fracti
 
 // This is an extended copy from AutomationList
 void
-AudioRegionGainLine::remove_point (ControlPoint& cp)
+AudioRegionGainLine::remove_points (std::vector<ControlPoint*> const& cps)
 {
 	trackview.editor().begin_reversible_command (_("remove control point"));
 	XMLNode &before = alist->get_state();
@@ -91,7 +91,15 @@ AudioRegionGainLine::remove_point (ControlPoint& cp)
 	}
 
 	trackview.editor ().get_selection ().clear_points ();
-	alist->erase (cp.model());
+
+	// Extract models before the ControlPoints iterator mutates on ControlPoint deletion
+	std::list<Evoral::ControlList::iterator> models;
+	for (auto const & cp : cps) {
+		models.push_back(cp->model());
+	}
+	for (auto const & model : models) {
+		alist->erase (model);
+	}
 
 	trackview.editor().session()->add_command (new MementoCommand<AutomationList>(*alist.get(), &before, &alist->get_state()));
 	trackview.editor().commit_reversible_command ();

Diff for: gtk2_ardour/region_gain_line.h

@@ -47,7 +47,7 @@ class AudioRegionGainLine : public AutomationLine
 	void start_drag_single (ControlPoint*, double, float);
 	void end_drag (bool with_push, uint32_t final_index);
 
-	void remove_point (ControlPoint&);
+	void remove_points (std::vector<ControlPoint*> const& cps);
 	AudioRegionView& region_view () { return rv; }
 
 private: