diff --git a/gtk2_ardour/grid_lines.cc b/gtk2_ardour/grid_lines.cc
index a83b7d074b..d4591b9e72 100644
--- a/gtk2_ardour/grid_lines.cc
+++ b/gtk2_ardour/grid_lines.cc
@@ -66,11 +66,11 @@ GridLines::draw (std::vector<Ruler::Mark>     marks)
 		samplepos_t s = m->position;
 
 		if ((*m).style == ArdourCanvas::Ruler::Mark::Major) {
-			lines.add_line (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, major_color);
+			lines.add_coord (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, major_color);
 		} else if ((*m).style == ArdourCanvas::Ruler::Mark::Minor) {
-			lines.add_line (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, minor_color);
+			lines.add_coord (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, minor_color);
 		} else {
-			lines.add_line (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, micro_color);
+			lines.add_coord (PublicEditor::instance().sample_to_pixel_unrounded (s), 1.0, micro_color);
 		}
 	}
 }
diff --git a/gtk2_ardour/midi_streamview.cc b/gtk2_ardour/midi_streamview.cc
index 8fe201a255..f00a268c05 100644
--- a/gtk2_ardour/midi_streamview.cc
+++ b/gtk2_ardour/midi_streamview.cc
@@ -342,7 +342,7 @@ MidiStreamView::draw_note_lines()
 		 */
 
 		if (i <= highest_note()) {
-			_note_lines->add_line (y, 1.0, UIConfiguration::instance().color ("piano roll black outline"));
+			_note_lines->add_coord (y, 1.0, UIConfiguration::instance().color ("piano roll black outline"));
 		}
 
 		/* now add a thicker line/bar which covers the entire vertical
@@ -366,7 +366,7 @@ MidiStreamView::draw_note_lines()
 		double mid = y + (h/2.0);
 
 		if (mid >= 0 && h > 1.0) {
-			_note_lines->add_line (mid, h, color);
+			_note_lines->add_coord (mid, h, color);
 		}
 
 		prev_y = y;
diff --git a/libs/canvas/canvas/box.h b/libs/canvas/canvas/box.h
index 2e1ca25002..b97e8c6f7b 100644
--- a/libs/canvas/canvas/box.h
+++ b/libs/canvas/canvas/box.h
@@ -21,7 +21,7 @@
 #ifndef __CANVAS_BOX_H__
 #define __CANVAS_BOX_H__
 
-#include "canvas/item.h"
+#include "canvas/rectangle.h"
 
 namespace ArdourCanvas
 {
@@ -39,7 +39,7 @@ class Rectangle;
  *
  *   Other?
  */
-class LIBCANVAS_API Box : public Item
+class LIBCANVAS_API Box : public Rectangle
 {
 public:
 	enum Orientation {
@@ -77,11 +77,10 @@ public:
 
 	void child_changed (bool bbox_changed);
   private:
-	Rectangle *self;
 	bool collapse_on_hide;
 	bool homogenous;
+	bool ignore_child_changes;
 
-	void reset_self ();
 	void reposition_children ();
 };
 
diff --git a/libs/canvas/canvas/line_set.h b/libs/canvas/canvas/line_set.h
index b7edac801c..6752f5ac3f 100644
--- a/libs/canvas/canvas/line_set.h
+++ b/libs/canvas/canvas/line_set.h
@@ -47,7 +47,7 @@ public:
 	void set_extent (Distance);
 	Distance extent() const { return _extent; }
 
-	void add_line (Coord, Distance, Gtkmm2ext::Color);
+	void add_coord (Coord, Distance, Gtkmm2ext::Color);
 	void clear ();
 
 	struct Line {
diff --git a/libs/canvas/line_set.cc b/libs/canvas/line_set.cc
index 24f41f4132..0cb60d9e7c 100644
--- a/libs/canvas/line_set.cc
+++ b/libs/canvas/line_set.cc
@@ -131,7 +131,7 @@ LineSet::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
 }
 
 void
-LineSet::add_line (Coord y, Distance width, Gtkmm2ext::Color color)
+LineSet::add_coord (Coord y, Distance width, Gtkmm2ext::Color color)
 {
 	begin_change ();