use newly factored canvas in gtk2_ardour

51 files changed, 163 insertions, 159 deletions

diff --git a/gtk2_ardour/audio_region_view.cc b/gtk2_ardour/audio_region_view.cc
index 928902bf42..63f081608d 100644
--- a/gtk2_ardour/audio_region_view.cc
+++ b/gtk2_ardour/audio_region_view.cc
@@ -75,7 +75,7 @@ using namespace ArdourCanvas;
 static const int32_t sync_mark_width = 9;
 static double const handle_size = 10; /* height of fade handles */
 
-AudioRegionView::AudioRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &tv, boost::shared_ptr<AudioRegion> r, double spu,
+AudioRegionView::AudioRegionView (ArdourCanvas::Layout *parent, RouteTimeAxisView &tv, boost::shared_ptr<AudioRegion> r, double spu,
 				  uint32_t basic_color)
 	: RegionView (parent, tv, r, spu, basic_color)
 	, sync_mark(0)
@@ -96,7 +96,7 @@ AudioRegionView::AudioRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView
 	Config->ParameterChanged.connect (*this, invalidator (*this), boost::bind (&AudioRegionView::parameter_changed, this, _1), gui_context());
 }
 
-AudioRegionView::AudioRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &tv, boost::shared_ptr<AudioRegion> r, double spu,
+AudioRegionView::AudioRegionView (ArdourCanvas::Layout *parent, RouteTimeAxisView &tv, boost::shared_ptr<AudioRegion> r, double spu,
 				  uint32_t basic_color, bool recording, TimeAxisViewItem::Visibility visibility)
 	: RegionView (parent, tv, r, spu, basic_color, recording, visibility)
 	, sync_mark(0)
diff --git a/gtk2_ardour/audio_region_view.h b/gtk2_ardour/audio_region_view.h
index ffadce0c59..11be83dc44 100644
--- a/gtk2_ardour/audio_region_view.h
+++ b/gtk2_ardour/audio_region_view.h
@@ -51,13 +51,13 @@ class RouteTimeAxisView;
 class AudioRegionView : public RegionView
 {
   public:
-	AudioRegionView (ArdourCanvas::Group *,
+	AudioRegionView (ArdourCanvas::Layout *,
 			 RouteTimeAxisView&,
 			 boost::shared_ptr<ARDOUR::AudioRegion>,
 			 double initial_samples_per_pixel,
 			 uint32_t base_color);
 
-	AudioRegionView (ArdourCanvas::Group *,
+	AudioRegionView (ArdourCanvas::Layout *,
 			 RouteTimeAxisView&,
 			 boost::shared_ptr<ARDOUR::AudioRegion>,
 			 double samples_per_pixel,
diff --git a/gtk2_ardour/automation_line.cc b/gtk2_ardour/automation_line.cc
index 670083e0d4..4040f8d3bd 100644
--- a/gtk2_ardour/automation_line.cc
+++ b/gtk2_ardour/automation_line.cc
@@ -70,7 +70,7 @@ using namespace Editing;
 /** @param converter A TimeConverter whose origin_b is the start time of the AutomationList in session frames.
  *  This will not be deleted by AutomationLine.
  */
-AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanvas::Group& parent,
+AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanvas::Item& parent,
                                 boost::shared_ptr<AutomationList> al,
                                 Evoral::TimeConverter<double, framepos_t>* converter)
 	: trackview (tv)
@@ -99,7 +99,7 @@ AutomationLine::AutomationLine (const string& name, TimeAxisView& tv, ArdourCanv
 	terminal_points_can_slide = true;
 	_height = 0;
 
-	group = new ArdourCanvas::Group (&parent);
+	group = new ArdourCanvas::Layout (&parent);
 	CANVAS_DEBUG_NAME (group, "region gain envelope group");
 
 	line = new ArdourCanvas::PolyLine (group);
diff --git a/gtk2_ardour/automation_line.h b/gtk2_ardour/automation_line.h
index 67e8fbc52b..5695527002 100644
--- a/gtk2_ardour/automation_line.h
+++ b/gtk2_ardour/automation_line.h
@@ -37,7 +37,7 @@
 #include "ardour/types.h"
 
 #include "canvas/types.h"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/poly_line.h"
 
 class AutomationLine;
@@ -60,7 +60,7 @@ public:
 		SelectedControlPoints = 0x4
 	};
 	
-	AutomationLine (const std::string& name, TimeAxisView&, ArdourCanvas::Group&,
+	AutomationLine (const std::string& name, TimeAxisView&, ArdourCanvas::Item&,
 	                boost::shared_ptr<ARDOUR::AutomationList>,
 	                Evoral::TimeConverter<double, ARDOUR::framepos_t>* converter = 0);
 	virtual ~AutomationLine ();
@@ -105,7 +105,7 @@ public:
 
 	TimeAxisView& trackview;
 
-	ArdourCanvas::Group& canvas_group() const { return *group; }
+	ArdourCanvas::Layout& canvas_group() const { return *group; }
 	ArdourCanvas::Item&  parent_group() const { return _parent_group; }
 	ArdourCanvas::Item&  grab_item() const { return *line; }
 
@@ -173,8 +173,8 @@ protected:
 	/** true if we did a push at any point during the current drag */
 	bool    did_push;
 
-	ArdourCanvas::Group&        _parent_group;
-	ArdourCanvas::Group*        group;
+	ArdourCanvas::Item&        _parent_group;
+	ArdourCanvas::Layout*       group;
 	ArdourCanvas::PolyLine*     line; /* line */
 	ArdourCanvas::Points        line_points; /* coordinates for canvas line */
 	std::vector<ControlPoint*>  control_points; /* visible control points */
diff --git a/gtk2_ardour/automation_region_view.cc b/gtk2_ardour/automation_region_view.cc
index 82c9278b01..44744fa39b 100644
--- a/gtk2_ardour/automation_region_view.cc
+++ b/gtk2_ardour/automation_region_view.cc
@@ -39,7 +39,7 @@
 
 #include "i18n.h"
 
-AutomationRegionView::AutomationRegionView (ArdourCanvas::Group*                      parent,
+AutomationRegionView::AutomationRegionView (ArdourCanvas::Layout*                      parent,
 					    AutomationTimeAxisView&                   time_axis,
 					    boost::shared_ptr<ARDOUR::Region>         region,
 					    const Evoral::Parameter&                  param,
diff --git a/gtk2_ardour/automation_region_view.h b/gtk2_ardour/automation_region_view.h
index 3b372bce7d..dd9d6a7f82 100644
--- a/gtk2_ardour/automation_region_view.h
+++ b/gtk2_ardour/automation_region_view.h
@@ -37,7 +37,7 @@ class TimeAxisView;
 class AutomationRegionView : public RegionView
 {
 public:
-	AutomationRegionView(ArdourCanvas::Group*,
+	AutomationRegionView(ArdourCanvas::Layout*,
 	                     AutomationTimeAxisView&,
 	                     boost::shared_ptr<ARDOUR::Region>,
 	                     const Evoral::Parameter& parameter,
diff --git a/gtk2_ardour/crossfade_view.h b/gtk2_ardour/crossfade_view.h
index 960bcc2d26..9e6e943904 100644
--- a/gtk2_ardour/crossfade_view.h
+++ b/gtk2_ardour/crossfade_view.h
@@ -36,7 +36,7 @@ namespace ArdourCanvas {
 class CrossfadeView : public TimeAxisViewItem
 {
 public:
-	CrossfadeView (ArdourCanvas::Group*,
+	CrossfadeView (ArdourCanvas::Layout*,
 		       RouteTimeAxisView&,
 		       boost::shared_ptr<ARDOUR::Crossfade>,
 		       double initial_samples_per_pixel,
diff --git a/gtk2_ardour/editor.h b/gtk2_ardour/editor.h
index 3aee8e87c6..6eb4be81f8 100644
--- a/gtk2_ardour/editor.h
+++ b/gtk2_ardour/editor.h
@@ -451,10 +451,10 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 		_stepping_axis_view = v;
 	}
 
- 	ArdourCanvas::Group* get_trackview_group () const { return _trackview_group; }
-        ArdourCanvas::Group* get_hscroll_group () const { return h_scroll_group; }
-        ArdourCanvas::Group* get_vscroll_group () const { return v_scroll_group; }
-        ArdourCanvas::Group* get_hvscroll_group () const { return hv_scroll_group; }
+ 	ArdourCanvas::Layout* get_trackview_group () const { return _trackview_group; }
+        ArdourCanvas::ScrollGroup* get_hscroll_group () const { return h_scroll_group; }
+        ArdourCanvas::ScrollGroup* get_vscroll_group () const { return v_scroll_group; }
+        ArdourCanvas::ScrollGroup* get_hvscroll_group () const { return hv_scroll_group; }
 
         ArdourCanvas::GtkCanvasViewport* get_track_canvas () const;
 
@@ -560,7 +560,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	void refresh_location_display ();
 	void refresh_location_display_internal (ARDOUR::Locations::LocationList&);
 	void add_new_location (ARDOUR::Location *);
-	ArdourCanvas::Group* add_new_location_internal (ARDOUR::Location *);
+	ArdourCanvas::Layout* add_new_location_internal (ARDOUR::Location *);
 	void location_gone (ARDOUR::Location *);
 	void remove_marker (ArdourCanvas::Item&, GdkEvent*);
 	gint really_remove_marker (ARDOUR::Location* loc);
@@ -606,7 +606,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	LocationMarkerMap location_markers;
 
 	void update_marker_labels ();
-	void update_marker_labels (ArdourCanvas::Group *);
+	void update_marker_labels (ArdourCanvas::Layout *);
 	void check_marker_label (Marker *);
 
 	/** A set of lists of Markers that are in each of the canvas groups
@@ -615,7 +615,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	 *  a marker has moved we can decide whether we need to update the labels
 	 *  for all markers or for just a few.
 	 */
-	std::map<ArdourCanvas::Group *, std::list<Marker *> > _sorted_marker_lists;
+	std::map<ArdourCanvas::Layout *, std::list<Marker *> > _sorted_marker_lists;
 	void remove_sorted_marker (Marker *);
 
 	void hide_marker (ArdourCanvas::Item*, GdkEvent*);
@@ -729,42 +729,42 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 	ArdourCanvas::Pixbuf     *logo_item;
 #if 0    
     /* these will be needed when we have canvas rulers */
-	ArdourCanvas::Group      *minsec_group;
-	ArdourCanvas::Group      *bbt_group;
-	ArdourCanvas::Group      *timecode_group;
-	ArdourCanvas::Group      *frame_group;
+	ArdourCanvas::Layout      *minsec_group;
+	ArdourCanvas::Layout      *bbt_group;
+	ArdourCanvas::Layout      *timecode_group;
+	ArdourCanvas::Layout      *frame_group;
 #endif
 
-	ArdourCanvas::Group      *tempo_group;
-	ArdourCanvas::Group      *meter_group;
-	ArdourCanvas::Group      *marker_group;
-	ArdourCanvas::Group      *range_marker_group;
-	ArdourCanvas::Group      *transport_marker_group;
-	ArdourCanvas::Group*      cd_marker_group;
+	ArdourCanvas::Layout      *tempo_group;
+	ArdourCanvas::Layout      *meter_group;
+	ArdourCanvas::Layout      *marker_group;
+	ArdourCanvas::Layout      *range_marker_group;
+	ArdourCanvas::Layout      *transport_marker_group;
+	ArdourCanvas::Layout*      cd_marker_group;
 
 	/* parent for groups which themselves contain time markers */
-	ArdourCanvas::Group*     _time_markers_group;
+	ArdourCanvas::Layout*     _time_markers_group;
 
 	/* The group containing all other groups that are scrolled vertically
 	   and horizontally.
 	*/
-        ArdourCanvas::Group* hv_scroll_group;
+        ArdourCanvas::ScrollGroup* hv_scroll_group;
 
 	/* The group containing all other groups that are scrolled vertically ONLY
 	*/
-        ArdourCanvas::Group* v_scroll_group;
+        ArdourCanvas::ScrollGroup* v_scroll_group;
 
 	/* The group containing all other groups that are scrolled horizontally ONLY
 	*/
-        ArdourCanvas::Group* h_scroll_group;
+        ArdourCanvas::ScrollGroup* h_scroll_group;
 
 	/* The group containing all trackviews. */
-	ArdourCanvas::Group* _trackview_group;
+	ArdourCanvas::Layout* _trackview_group;
 
 	/* The group holding things (mostly regions) while dragging so they
 	 * are on top of everything else
 	 */
-	ArdourCanvas::Group* _drag_motion_group;
+	ArdourCanvas::Layout* _drag_motion_group;
 
         /* a rect that sits at the bottom of all tracks to act as a drag-no-drop/clickable
 	 * target area.
@@ -898,7 +898,7 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	/* videtimline related actions */
 	Gtk::Label                videotl_label;
-	ArdourCanvas::Group*      videotl_group;
+	ArdourCanvas::Layout*      videotl_group;
 	Glib::RefPtr<Gtk::ToggleAction> ruler_video_action;
 	Glib::RefPtr<Gtk::ToggleAction> xjadeo_proc_action;
 	Glib::RefPtr<Gtk::ToggleAction> xjadeo_ontop_action;
@@ -1478,8 +1478,8 @@ class Editor : public PublicEditor, public PBD::ScopedConnectionList, public ARD
 
 	TempoLines* tempo_lines;
 
-	ArdourCanvas::Group* global_rect_group;
-	ArdourCanvas::Group* time_line_group;
+	ArdourCanvas::Layout* global_rect_group;
+	ArdourCanvas::Layout* time_line_group;
 
 	void hide_measures ();
         void draw_measures (ARDOUR::TempoMap::BBTPointList::const_iterator& begin,
diff --git a/gtk2_ardour/editor_canvas.cc b/gtk2_ardour/editor_canvas.cc
index ed30d4b364..ce20b841ad 100644
--- a/gtk2_ardour/editor_canvas.cc
+++ b/gtk2_ardour/editor_canvas.cc
@@ -101,7 +101,7 @@ Editor::initialize_canvas ()
 	}
 
 	/*a group to hold global rects like punch/loop indicators */
-	global_rect_group = new ArdourCanvas::Group (hv_scroll_group);
+	global_rect_group = new ArdourCanvas::Layout (hv_scroll_group);
 	CANVAS_DEBUG_NAME (global_rect_group, "global rect group");
 
         transport_loop_range_rect = new ArdourCanvas::Rectangle (global_rect_group, ArdourCanvas::Rect (0.0, 0.0, 0.0, ArdourCanvas::COORD_MAX));
@@ -113,10 +113,10 @@ Editor::initialize_canvas ()
 	transport_punch_range_rect->hide();
 
 	/*a group to hold time (measure) lines */
-	time_line_group = new ArdourCanvas::Group (hv_scroll_group);
+	time_line_group = new ArdourCanvas::Layout (hv_scroll_group);
 	CANVAS_DEBUG_NAME (time_line_group, "time line group");
 
-	_trackview_group = new ArdourCanvas::Group (hv_scroll_group);
+	_trackview_group = new ArdourCanvas::Layout (hv_scroll_group);
 	CANVAS_DEBUG_NAME (_trackview_group, "Canvas TrackViews");
 	
 	// used to show zoom mode active zooming
@@ -131,30 +131,30 @@ Editor::initialize_canvas ()
 	/* a group to hold stuff while it gets dragged around. Must be the
 	 * uppermost (last) group with hv_scroll_group as a parent
 	 */
-	_drag_motion_group = new ArdourCanvas::Group (hv_scroll_group);                                                                                                                                     
+	_drag_motion_group = new ArdourCanvas::Layout (hv_scroll_group);                                                                                                                                     
         CANVAS_DEBUG_NAME (_drag_motion_group, "Canvas Drag Motion");
 
 	/* TIME BAR CANVAS */
 	
-	_time_markers_group = new ArdourCanvas::Group (h_scroll_group);
+	_time_markers_group = new ArdourCanvas::Layout (h_scroll_group);
 	CANVAS_DEBUG_NAME (_time_markers_group, "time bars");
 
-	cd_marker_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, 0.0));
+	cd_marker_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, 0.0));
 	CANVAS_DEBUG_NAME (cd_marker_group, "cd marker group");
 	/* the vide is temporarily placed a the same location as the
 	   cd_marker_group, but is moved later.
 	*/
-	videotl_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple(0.0, 0.0));
+	videotl_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple(0.0, 0.0));
 	CANVAS_DEBUG_NAME (videotl_group, "videotl group");
-	marker_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, timebar_height + 1.0));
+	marker_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, timebar_height + 1.0));
 	CANVAS_DEBUG_NAME (marker_group, "marker group");
-	transport_marker_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 2.0) + 1.0));
+	transport_marker_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 2.0) + 1.0));
 	CANVAS_DEBUG_NAME (transport_marker_group, "transport marker group");
-	range_marker_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 3.0) + 1.0));
+	range_marker_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 3.0) + 1.0));
 	CANVAS_DEBUG_NAME (range_marker_group, "range marker group");
-	tempo_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 4.0) + 1.0));
+	tempo_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 4.0) + 1.0));
 	CANVAS_DEBUG_NAME (tempo_group, "tempo group");
-	meter_group = new ArdourCanvas::Group (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 5.0) + 1.0));
+	meter_group = new ArdourCanvas::Layout (_time_markers_group, ArdourCanvas::Duple (0.0, (timebar_height * 5.0) + 1.0));
 	CANVAS_DEBUG_NAME (meter_group, "meter group");
 
 	meter_bar = new ArdourCanvas::Rectangle (meter_group, ArdourCanvas::Rect (0.0, 0.0, ArdourCanvas::COORD_MAX, timebar_height));
diff --git a/gtk2_ardour/editor_cursors.cc b/gtk2_ardour/editor_cursors.cc
index a820b5fc1f..dd9970c730 100644
--- a/gtk2_ardour/editor_cursors.cc
+++ b/gtk2_ardour/editor_cursors.cc
@@ -22,6 +22,7 @@
 
 #include "canvas/canvas.h"
 #include "canvas/debug.h"
+#include "canvas/scroll_group.h"
 
 #include "utils.h"
 #include "editor_cursors.h"
diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index fb983f33f6..4019eb24c2 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -736,8 +736,8 @@ RegionMotionDrag::motion (GdkEvent* event, bool first_move)
 			/* reparent the regionview into a group above all
 			 * others
 			 */
-
-			ArdourCanvas::Group* rvg = rv->get_canvas_group();                                                                                                                                     
+			
+			ArdourCanvas::Item* rvg = rv->get_canvas_group();
                         Duple rv_canvas_offset = rvg->parent()->canvas_origin ();
                         Duple dmg_canvas_offset = _editor->_drag_motion_group->canvas_origin ();
                         rv->get_canvas_group()->reparent (_editor->_drag_motion_group);
diff --git a/gtk2_ardour/editor_markers.cc b/gtk2_ardour/editor_markers.cc
index 371feaff58..66edefc211 100644
--- a/gtk2_ardour/editor_markers.cc
+++ b/gtk2_ardour/editor_markers.cc
@@ -64,7 +64,7 @@ Editor::add_new_location (Location *location)
 {
 	ENSURE_GUI_THREAD (*this, &Editor::add_new_location, location);
 
-	ArdourCanvas::Group* group = add_new_location_internal (location);
+	ArdourCanvas::Layout* group = add_new_location_internal (location);
 
 	/* Do a full update of the markers in this group */
 	update_marker_labels (group);
@@ -82,14 +82,14 @@ Editor::add_new_location (Location *location)
  *  the caller must call update_marker_labels () after calling this.
  *  @return canvas group that the location's marker was added to.
  */
-ArdourCanvas::Group*
+ArdourCanvas::Layout*
 Editor::add_new_location_internal (Location* location)
 {
 	LocationMarkers *lam = new LocationMarkers;
 	uint32_t color;
 
 	/* make a note here of which group this marker ends up in */
-	ArdourCanvas::Group* group = 0;
+	ArdourCanvas::Layout* group = 0;
 
 	if (location->is_cd_marker()) {
 		color = location_cd_marker_color;
@@ -311,14 +311,14 @@ struct MarkerComparator {
 void
 Editor::update_marker_labels ()
 {
-	for (std::map<ArdourCanvas::Group *, std::list<Marker *> >::iterator i = _sorted_marker_lists.begin(); i != _sorted_marker_lists.end(); ++i) {
+	for (std::map<ArdourCanvas::Layout *, std::list<Marker *> >::iterator i = _sorted_marker_lists.begin(); i != _sorted_marker_lists.end(); ++i) {
 		update_marker_labels (i->first);
 	}
 }
 
 /** Look at all markers in a group and update label widths */
 void
-Editor::update_marker_labels (ArdourCanvas::Group* group)
+Editor::update_marker_labels (ArdourCanvas::Layout* group)
 {
 	list<Marker*>& sorted = _sorted_marker_lists[group];
 
@@ -1576,7 +1576,7 @@ Editor::toggle_marker_lines ()
 void
 Editor::remove_sorted_marker (Marker* m)
 {
-	for (std::map<ArdourCanvas::Group *, std::list<Marker *> >::iterator i = _sorted_marker_lists.begin(); i != _sorted_marker_lists.end(); ++i) {
+	for (std::map<ArdourCanvas::Layout *, std::list<Marker *> >::iterator i = _sorted_marker_lists.begin(); i != _sorted_marker_lists.end(); ++i) {
 		i->second.remove (m);
 	}
 }
diff --git a/gtk2_ardour/editor_rulers.cc b/gtk2_ardour/editor_rulers.cc
index 01a6940cea..7b9a2a495b 100644
--- a/gtk2_ardour/editor_rulers.cc
+++ b/gtk2_ardour/editor_rulers.cc
@@ -29,10 +29,11 @@
 
 #include <gtk/gtkaction.h>
 
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/canvas.h"
 #include "canvas/ruler.h"
 #include "canvas/debug.h"
+#include "canvas/scroll_group.h"
 
 #include "ardour/session.h"
 #include "ardour/tempo.h"
diff --git a/gtk2_ardour/ghostregion.cc b/gtk2_ardour/ghostregion.cc
index da2beeeca7..4c3e904c72 100644
--- a/gtk2_ardour/ghostregion.cc
+++ b/gtk2_ardour/ghostregion.cc
@@ -18,7 +18,7 @@
 */
 
 #include "evoral/Note.hpp"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/rectangle.h"
 #include "canvas/wave_view.h"
 #include "canvas/debug.h"
@@ -38,11 +38,11 @@ using namespace ARDOUR;
 
 PBD::Signal1<void,GhostRegion*> GhostRegion::CatchDeletion;
 
-GhostRegion::GhostRegion (ArdourCanvas::Group* parent, TimeAxisView& tv, TimeAxisView& source_tv, double initial_pos)
+GhostRegion::GhostRegion (ArdourCanvas::Layout* parent, TimeAxisView& tv, TimeAxisView& source_tv, double initial_pos)
 	: trackview (tv)
 	, source_trackview (source_tv)
 {
-	group = new ArdourCanvas::Group (parent);
+	group = new ArdourCanvas::Layout (parent);
 	CANVAS_DEBUG_NAME (group, "ghost region");
 	group->set_position (ArdourCanvas::Duple (initial_pos, 0));
 
@@ -191,7 +191,7 @@ MidiGhostRegion::~MidiGhostRegion()
 	clear_events ();
 }
 
-MidiGhostRegion::GhostEvent::GhostEvent (NoteBase* e, ArdourCanvas::Group* g)
+MidiGhostRegion::GhostEvent::GhostEvent (NoteBase* e, ArdourCanvas::Layout* g)
 	: event (e)
 {
 	rect = new ArdourCanvas::Rectangle (g, ArdourCanvas::Rect (e->x0(), e->y0(), e->x1(), e->y1()));
diff --git a/gtk2_ardour/ghostregion.h b/gtk2_ardour/ghostregion.h
index e8271a8ad8..851c5502f8 100644
--- a/gtk2_ardour/ghostregion.h
+++ b/gtk2_ardour/ghostregion.h
@@ -36,7 +36,7 @@ class TimeAxisView;
 class GhostRegion : public sigc::trackable
 {
 public:
-	GhostRegion(ArdourCanvas::Group* parent, TimeAxisView& tv, TimeAxisView& source_tv, double initial_unit_pos);
+	GhostRegion(ArdourCanvas::Layout* parent, TimeAxisView& tv, TimeAxisView& source_tv, double initial_unit_pos);
 	virtual ~GhostRegion();
 
 	virtual void set_samples_per_pixel (double) = 0;
@@ -52,7 +52,7 @@ public:
 	TimeAxisView& trackview;
 	/** TimeAxisView that we are a ghost for */
 	TimeAxisView& source_trackview;
-	ArdourCanvas::Group* group;
+	ArdourCanvas::Layout* group;
 	ArdourCanvas::Rectangle* base_rect;
 
 	static PBD::Signal1<void,GhostRegion*> CatchDeletion;
@@ -73,7 +73,7 @@ class MidiGhostRegion : public GhostRegion {
 public:
 	class GhostEvent : public sigc::trackable {
 	  public:
-	    GhostEvent(::NoteBase *, ArdourCanvas::Group *);
+	    GhostEvent(::NoteBase *, ArdourCanvas::Layout *);
 	    virtual ~GhostEvent ();
 	    
 	    NoteBase* event;
diff --git a/gtk2_ardour/hit.cc b/gtk2_ardour/hit.cc
index 69dd8d5bc8..c06160f3b2 100644
--- a/gtk2_ardour/hit.cc
+++ b/gtk2_ardour/hit.cc
@@ -30,10 +30,10 @@
 using namespace ARDOUR;
 using namespace ArdourCanvas;
 
-Hit::Hit (MidiRegionView& region, Group* group, double size, const boost::shared_ptr<NoteType> note, bool with_events) 
+Hit::Hit (MidiRegionView& region, Item* parent, double size, const boost::shared_ptr<NoteType> note, bool with_events) 
 	: NoteBase (region, with_events, note)
 {
-	_polygon = new ArdourCanvas::Polygon (group);
+	_polygon = new ArdourCanvas::Polygon (parent);
 	CANVAS_DEBUG_NAME (_polygon, "note");
 	set_item (_polygon);
 	set_height (size);
diff --git a/gtk2_ardour/hit.h b/gtk2_ardour/hit.h
index 0a02501606..5a6cef9943 100644
--- a/gtk2_ardour/hit.h
+++ b/gtk2_ardour/hit.h
@@ -33,7 +33,7 @@ public:
 	typedef Evoral::Note<double> NoteType;
 
 	Hit (MidiRegionView&                   region,
-	     ArdourCanvas::Group*              group,
+	     ArdourCanvas::Item*               parent,
 	     double                            size,
 	     const boost::shared_ptr<NoteType> note = boost::shared_ptr<NoteType>(),
 	     bool with_events = true);
diff --git a/gtk2_ardour/marker.cc b/gtk2_ardour/marker.cc
index ed24f20e84..ea47929db7 100644
--- a/gtk2_ardour/marker.cc
+++ b/gtk2_ardour/marker.cc
@@ -21,11 +21,12 @@
 #include "ardour/tempo.h"
 
 #include "canvas/rectangle.h"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/line.h"
 #include "canvas/polygon.h"
 #include "canvas/text.h"
 #include "canvas/canvas.h"
+#include "canvas/scroll_group.h"
 #include "canvas/debug.h"
 
 #include "ardour_ui.h"
@@ -52,7 +53,7 @@ PBD::Signal1<void,Marker*> Marker::CatchDeletion;
 
 static const double marker_height = 13.0;
 
-Marker::Marker (PublicEditor& ed, ArdourCanvas::Group& parent, guint32 rgba, const string& annotation,
+Marker::Marker (PublicEditor& ed, ArdourCanvas::Layout& parent, guint32 rgba, const string& annotation,
 		Type type, framepos_t frame, bool handle_events)
 
 	: editor (ed)
@@ -241,7 +242,7 @@ Marker::Marker (PublicEditor& ed, ArdourCanvas::Group& parent, guint32 rgba, con
 	unit_position = editor.sample_to_pixel (frame);
 	unit_position -= _shift;
 
-	group = new ArdourCanvas::Group (&parent, ArdourCanvas::Duple (unit_position, 0));
+	group = new ArdourCanvas::Layout (&parent, ArdourCanvas::Duple (unit_position, 0));
 #ifdef CANVAS_DEBUG
 	group->name = string_compose ("Marker::group for %1", annotation);
 #endif	
@@ -301,7 +302,7 @@ Marker::~Marker ()
 	delete _track_canvas_line;
 }
 
-void Marker::reparent(ArdourCanvas::Group & parent)
+void Marker::reparent(ArdourCanvas::Layout & parent)
 {
 	group->reparent (&parent);
 	_parent = &parent;
@@ -500,7 +501,7 @@ Marker::set_right_label_limit (double p)
 
 /***********************************************************************/
 
-TempoMarker::TempoMarker (PublicEditor& editor, ArdourCanvas::Group& parent, guint32 rgba, const string& text,
+TempoMarker::TempoMarker (PublicEditor& editor, ArdourCanvas::Layout& parent, guint32 rgba, const string& text,
 			  ARDOUR::TempoSection& temp)
 	: Marker (editor, parent, rgba, text, Tempo, 0, false),
 	  _tempo (temp)
@@ -515,7 +516,7 @@ TempoMarker::~TempoMarker ()
 
 /***********************************************************************/
 
-MeterMarker::MeterMarker (PublicEditor& editor, ArdourCanvas::Group& parent, guint32 rgba, const string& text,
+MeterMarker::MeterMarker (PublicEditor& editor, ArdourCanvas::Layout& parent, guint32 rgba, const string& text,
 			  ARDOUR::MeterSection& m)
 	: Marker (editor, parent, rgba, text, Meter, 0, false),
 	  _meter (m)
diff --git a/gtk2_ardour/marker.h b/gtk2_ardour/marker.h
index 727f4bee18..facaaffb09 100644
--- a/gtk2_ardour/marker.h
+++ b/gtk2_ardour/marker.h
@@ -56,7 +56,7 @@ class Marker : public sigc::trackable
 	};
 
 
-	Marker (PublicEditor& editor, ArdourCanvas::Group &, guint32 rgba, const std::string& text, Type,
+	Marker (PublicEditor& editor, ArdourCanvas::Layout &, guint32 rgba, const std::string& text, Type,
 		framepos_t frame = 0, bool handle_events = true);
 
 	virtual ~Marker ();
@@ -76,8 +76,8 @@ class Marker : public sigc::trackable
 
 	framepos_t position() const { return frame_position; }
 
-	ArdourCanvas::Group * get_parent() { return _parent; }
-	void reparent (ArdourCanvas::Group & parent);
+	ArdourCanvas::Layout * get_parent() { return _parent; }
+	void reparent (ArdourCanvas::Layout & parent);
 
 	void hide ();
 	void show ();
@@ -98,8 +98,8 @@ class Marker : public sigc::trackable
 
 	Pango::FontDescription name_font;
 
-	ArdourCanvas::Group* _parent;
-	ArdourCanvas::Group *group;
+	ArdourCanvas::Layout* _parent;
+	ArdourCanvas::Layout *group;
 	ArdourCanvas::Polygon *mark;
         ArdourCanvas::Text *_name_item;
 	ArdourCanvas::Points *points;
@@ -134,7 +134,7 @@ private:
 class TempoMarker : public Marker
 {
   public:
-        TempoMarker (PublicEditor& editor, ArdourCanvas::Group &, guint32 rgba, const std::string& text, ARDOUR::TempoSection&);
+        TempoMarker (PublicEditor& editor, ArdourCanvas::Layout &, guint32 rgba, const std::string& text, ARDOUR::TempoSection&);
 	~TempoMarker ();
 
 	ARDOUR::TempoSection& tempo() const { return _tempo; }
@@ -146,7 +146,7 @@ class TempoMarker : public Marker
 class MeterMarker : public Marker
 {
   public:
-        MeterMarker (PublicEditor& editor, ArdourCanvas::Group &, guint32 rgba, const std::string& text, ARDOUR::MeterSection&);
+        MeterMarker (PublicEditor& editor, ArdourCanvas::Layout &, guint32 rgba, const std::string& text, ARDOUR::MeterSection&);
 	~MeterMarker ();
 
 	ARDOUR::MeterSection& meter() const { return _meter; }
diff --git a/gtk2_ardour/midi_automation_line.cc b/gtk2_ardour/midi_automation_line.cc
index 971944266f..e5f30493d7 100644
--- a/gtk2_ardour/midi_automation_line.cc
+++ b/gtk2_ardour/midi_automation_line.cc
@@ -29,12 +29,12 @@ using namespace std;
 MidiAutomationLine::MidiAutomationLine (
 	const std::string&                                      name,
 	TimeAxisView&                                           tav,
-	ArdourCanvas::Group&                                    group,
+	ArdourCanvas::Item&                                     parent,
 	boost::shared_ptr<ARDOUR::AutomationList>               list,
 	boost::shared_ptr<ARDOUR::MidiRegion>                   region,
 	Evoral::Parameter                                       parameter,
 	Evoral::TimeConverter<double, ARDOUR::framepos_t>*      converter)
-	: AutomationLine (name, tav, group, list, converter)
+	: AutomationLine (name, tav, parent, list, converter)
 	, _region (region)
 	, _parameter (parameter)
 {
diff --git a/gtk2_ardour/midi_automation_line.h b/gtk2_ardour/midi_automation_line.h
index df4db06c2c..3748c35bd4 100644
--- a/gtk2_ardour/midi_automation_line.h
+++ b/gtk2_ardour/midi_automation_line.h
@@ -26,7 +26,7 @@
 class MidiAutomationLine : public AutomationLine
 {
 public:
-	MidiAutomationLine (const std::string&, TimeAxisView&, ArdourCanvas::Group&,
+	MidiAutomationLine (const std::string&, TimeAxisView&, ArdourCanvas::Item&,
 	                    boost::shared_ptr<ARDOUR::AutomationList>,
 	                    boost::shared_ptr<ARDOUR::MidiRegion>,
 	                    Evoral::Parameter,
diff --git a/gtk2_ardour/midi_region_view.cc b/gtk2_ardour/midi_region_view.cc
index db3f4760bc..b20727889a 100644
--- a/gtk2_ardour/midi_region_view.cc
+++ b/gtk2_ardour/midi_region_view.cc
@@ -88,13 +88,13 @@ PBD::Signal1<void, MidiRegionView *> MidiRegionView::SelectionCleared;
 
 #define MIDI_BP_ZERO ((Config->get_first_midi_bank_is_zero())?0:1)
 
-MidiRegionView::MidiRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &tv,
+MidiRegionView::MidiRegionView (ArdourCanvas::Layout *parent, RouteTimeAxisView &tv,
                                 boost::shared_ptr<MidiRegion> r, double spu, uint32_t basic_color)
 	: RegionView (parent, tv, r, spu, basic_color)
 	, _current_range_min(0)
 	, _current_range_max(0)
 	, _active_notes(0)
-	, _note_group (new ArdourCanvas::Group (group))
+	, _note_group (new ArdourCanvas::Layout (group))
 	, _note_diff_command (0)
 	, _ghost_note(0)
 	, _step_edit_cursor (0)
@@ -124,14 +124,14 @@ MidiRegionView::MidiRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &
 	SelectionCleared.connect (_selection_cleared_connection, invalidator (*this), boost::bind (&MidiRegionView::selection_cleared, this, _1), gui_context ());
 }
 
-MidiRegionView::MidiRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &tv,
+MidiRegionView::MidiRegionView (ArdourCanvas::Layout *parent, RouteTimeAxisView &tv,
                                 boost::shared_ptr<MidiRegion> r, double spu, uint32_t basic_color,
                                 TimeAxisViewItem::Visibility visibility)
 	: RegionView (parent, tv, r, spu, basic_color, false, visibility)
 	, _current_range_min(0)
 	, _current_range_max(0)
 	, _active_notes(0)
-	, _note_group (new ArdourCanvas::Group (parent))
+	, _note_group (new ArdourCanvas::Layout (parent))
 	, _note_diff_command (0)
 	, _ghost_note(0)
 	, _step_edit_cursor (0)
@@ -177,7 +177,7 @@ MidiRegionView::MidiRegionView (const MidiRegionView& other)
 	, _current_range_min(0)
 	, _current_range_max(0)
 	, _active_notes(0)
-	, _note_group (new ArdourCanvas::Group (get_canvas_group()))
+	, _note_group (new ArdourCanvas::Layout (get_canvas_group()))
 	, _note_diff_command (0)
 	, _ghost_note(0)
 	, _step_edit_cursor (0)
@@ -205,7 +205,7 @@ MidiRegionView::MidiRegionView (const MidiRegionView& other, boost::shared_ptr<M
 	, _current_range_min(0)
 	, _current_range_max(0)
 	, _active_notes(0)
-	, _note_group (new ArdourCanvas::Group (get_canvas_group()))
+	, _note_group (new ArdourCanvas::Layout (get_canvas_group()))
 	, _note_diff_command (0)
 	, _ghost_note(0)
 	, _step_edit_cursor (0)
@@ -3610,7 +3610,7 @@ void
 MidiRegionView::show_step_edit_cursor (Evoral::MusicalTime pos)
 {
 	if (_step_edit_cursor == 0) {
-		ArdourCanvas::Group* const group = (ArdourCanvas::Group*)get_canvas_group();
+		ArdourCanvas::Layout* const group = (ArdourCanvas::Layout*)get_canvas_group();
 
 		_step_edit_cursor = new ArdourCanvas::Rectangle (group);
 		_step_edit_cursor->set_y0 (0);
@@ -3725,7 +3725,7 @@ MidiRegionView::trim_front_starting ()
 	/* Reparent the note group to the region view's parent, so that it doesn't change
 	   when the region view is trimmed.
 	*/
-	_temporary_note_group = new ArdourCanvas::Group (group->parent ());
+	_temporary_note_group = new ArdourCanvas::Layout (group->parent ());
 	_temporary_note_group->move (group->position ());
 	_note_group->reparent (_temporary_note_group);
 }
diff --git a/gtk2_ardour/midi_region_view.h b/gtk2_ardour/midi_region_view.h
index 0f4dd52ff4..213d97795e 100644
--- a/gtk2_ardour/midi_region_view.h
+++ b/gtk2_ardour/midi_region_view.h
@@ -67,7 +67,7 @@ public:
 	typedef Evoral::Note<Evoral::MusicalTime> NoteType;
 	typedef Evoral::Sequence<Evoral::MusicalTime>::Notes Notes;
 
-	MidiRegionView (ArdourCanvas::Group *,
+	MidiRegionView (ArdourCanvas::Layout *,
 	                RouteTimeAxisView&,
 	                boost::shared_ptr<ARDOUR::MidiRegion>,
 	                double initial_samples_per_pixel,
@@ -309,7 +309,7 @@ protected:
 	/** Allows derived types to specify their visibility requirements
 	 * to the TimeAxisViewItem parent class.
 	 */
-	MidiRegionView (ArdourCanvas::Group *,
+	MidiRegionView (ArdourCanvas::Layout *,
 	                RouteTimeAxisView&,
 	                boost::shared_ptr<ARDOUR::MidiRegion>,
 	                double samples_per_pixel,
@@ -387,7 +387,7 @@ private:
 	PatchChanges                         _patch_changes;
 	SysExes                              _sys_exes;
 	Note**                               _active_notes;
-	ArdourCanvas::Group*                 _note_group;
+	ArdourCanvas::Layout*                 _note_group;
 	ARDOUR::MidiModel::NoteDiffCommand*  _note_diff_command;
 	Note*                                _ghost_note;
 	double                               _last_ghost_x;
@@ -401,7 +401,7 @@ private:
 	/** A group used to temporarily reparent _note_group to during start trims, so
 	 *  that the notes don't move with the parent region view.
 	 */
-	ArdourCanvas::Group*                 _temporary_note_group;
+	ArdourCanvas::Layout*                 _temporary_note_group;
 
 	MouseState _mouse_state;
 	int _pressed_button;
diff --git a/gtk2_ardour/midi_streamview.cc b/gtk2_ardour/midi_streamview.cc
index b8bd0c257b..b687020e3d 100644
--- a/gtk2_ardour/midi_streamview.cc
+++ b/gtk2_ardour/midi_streamview.cc
@@ -68,7 +68,7 @@ MidiStreamView::MidiStreamView (MidiTimeAxisView& tv)
 	, _updates_suspended (false)
 {
 	/* use a group dedicated to MIDI underlays. Audio underlays are not in this group. */
-	midi_underlay_group = new ArdourCanvas::Group (_canvas_group);
+	midi_underlay_group = new ArdourCanvas::Layout (_canvas_group);
 	midi_underlay_group->lower_to_bottom();
 
 	/* put the note lines in the timeaxisview's group, so it
diff --git a/gtk2_ardour/midi_streamview.h b/gtk2_ardour/midi_streamview.h
index b3506d4224..6cd9d10e21 100644
--- a/gtk2_ardour/midi_streamview.h
+++ b/gtk2_ardour/midi_streamview.h
@@ -68,7 +68,7 @@ class MidiStreamView : public StreamView
 	};
 
 	Gtk::Adjustment note_range_adjustment;
-	ArdourCanvas::Group* midi_underlay_group;
+	ArdourCanvas::Layout* midi_underlay_group;
 
 	void set_note_range(VisibleNoteRange r);
 
diff --git a/gtk2_ardour/note.cc b/gtk2_ardour/note.cc
index 3adcd751f8..dc8decf837 100644
--- a/gtk2_ardour/note.cc
+++ b/gtk2_ardour/note.cc
@@ -31,9 +31,9 @@ using namespace ARDOUR;
 using namespace ArdourCanvas;
 
 Note::Note (
-	MidiRegionView& region, Group* group, const boost::shared_ptr<NoteType> note, bool with_events)
+	MidiRegionView& region, Item* parent, const boost::shared_ptr<NoteType> note, bool with_events)
 	: NoteBase (region, with_events, note)
-	, _rectangle (new ArdourCanvas::Rectangle (group))
+	, _rectangle (new ArdourCanvas::Rectangle (parent))
 {
 	CANVAS_DEBUG_NAME (_rectangle, "note");
 	set_item (_rectangle);
diff --git a/gtk2_ardour/note.h b/gtk2_ardour/note.h
index c6bcd957e3..944dbf1b2e 100644
--- a/gtk2_ardour/note.h
+++ b/gtk2_ardour/note.h
@@ -26,7 +26,7 @@
 #include "midi_util.h"
 
 namespace ArdourCanvas {
-	class Group;
+	class Layout;
 }
 
 class Note : public NoteBase
@@ -35,7 +35,7 @@ public:
 	typedef Evoral::Note<Evoral::MusicalTime> NoteType;
 
 	Note (MidiRegionView&                   region,
-	      ArdourCanvas::Group*              group,
+	      ArdourCanvas::Item*               parent,
 	      const boost::shared_ptr<NoteType> note = boost::shared_ptr<NoteType>(),
 	      bool with_events = true);
 
diff --git a/gtk2_ardour/patch_change.cc b/gtk2_ardour/patch_change.cc
index 6be40811bf..a029563f0f 100644
--- a/gtk2_ardour/patch_change.cc
+++ b/gtk2_ardour/patch_change.cc
@@ -43,7 +43,7 @@ using namespace std;
  */
 PatchChange::PatchChange(
 		MidiRegionView& region,
-		ArdourCanvas::Group* parent,
+		ArdourCanvas::Layout* parent,
 		const string&   text,
 		double          height,
 		double          x,
diff --git a/gtk2_ardour/patch_change.h b/gtk2_ardour/patch_change.h
index 652f9d66c1..ed1f4aadf4 100644
--- a/gtk2_ardour/patch_change.h
+++ b/gtk2_ardour/patch_change.h
@@ -35,7 +35,7 @@ class PatchChange
 public:
 	PatchChange(
 		MidiRegionView& region,
-		ArdourCanvas::Group* parent,
+		ArdourCanvas::Layout* parent,
 		const string&   text,
 		double          height,
 		double          x,
diff --git a/gtk2_ardour/public_editor.h b/gtk2_ardour/public_editor.h
index a0f5e74ef9..86e9e16cdd 100644
--- a/gtk2_ardour/public_editor.h
+++ b/gtk2_ardour/public_editor.h
@@ -365,10 +365,10 @@ class PublicEditor : public Gtk::Window, public PBD::StatefulDestructible, publi
 	virtual Gtk::HBox& get_status_bar_packer() = 0;
 #endif
 
-	virtual ArdourCanvas::Group* get_trackview_group () const = 0;
-	virtual ArdourCanvas::Group* get_hscroll_group () const = 0;
-	virtual ArdourCanvas::Group* get_vscroll_group () const = 0;
-	virtual ArdourCanvas::Group* get_hvscroll_group () const = 0;
+	virtual ArdourCanvas::Layout* get_trackview_group () const = 0;
+	virtual ArdourCanvas::ScrollGroup* get_hscroll_group () const = 0;
+	virtual ArdourCanvas::ScrollGroup* get_vscroll_group () const = 0;
+	virtual ArdourCanvas::ScrollGroup* get_hvscroll_group () const = 0;
 
         virtual ArdourCanvas::GtkCanvasViewport* get_track_canvas() const = 0;
 
diff --git a/gtk2_ardour/region_gain_line.cc b/gtk2_ardour/region_gain_line.cc
index 827ebde12d..d0fd762e24 100644
--- a/gtk2_ardour/region_gain_line.cc
+++ b/gtk2_ardour/region_gain_line.cc
@@ -38,7 +38,7 @@ using namespace std;
 using namespace ARDOUR;
 using namespace PBD;
 
-AudioRegionGainLine::AudioRegionGainLine (const string & name, AudioRegionView& r, ArdourCanvas::Group& parent, boost::shared_ptr<AutomationList> l)
+AudioRegionGainLine::AudioRegionGainLine (const string & name, AudioRegionView& r, ArdourCanvas::Layout& parent, boost::shared_ptr<AutomationList> l)
 	: AutomationLine (name, r.get_time_axis_view(), parent, l)
 	, rv (r)
 {
diff --git a/gtk2_ardour/region_gain_line.h b/gtk2_ardour/region_gain_line.h
index 1eae91bc27..998f3b3cf2 100644
--- a/gtk2_ardour/region_gain_line.h
+++ b/gtk2_ardour/region_gain_line.h
@@ -35,7 +35,7 @@ class AudioRegionView;
 class AudioRegionGainLine : public AutomationLine
 {
   public:
-	AudioRegionGainLine (const std::string & name, AudioRegionView&, ArdourCanvas::Group& parent, boost::shared_ptr<ARDOUR::AutomationList>);
+	AudioRegionGainLine (const std::string & name, AudioRegionView&, ArdourCanvas::Layout& parent, boost::shared_ptr<ARDOUR::AutomationList>);
 
         void start_drag_single (ControlPoint*, double, float);
         void end_drag (bool with_push, uint32_t final_index);
diff --git a/gtk2_ardour/region_view.cc b/gtk2_ardour/region_view.cc
index aee25b2e01..4a732b6360 100644
--- a/gtk2_ardour/region_view.cc
+++ b/gtk2_ardour/region_view.cc
@@ -63,7 +63,7 @@ static const int32_t sync_mark_width = 9;
 
 PBD::Signal1<void,RegionView*> RegionView::RegionViewGoingAway;
 
-RegionView::RegionView (ArdourCanvas::Group*              parent,
+RegionView::RegionView (ArdourCanvas::Layout*              parent,
                         TimeAxisView&                     tv,
                         boost::shared_ptr<ARDOUR::Region> r,
                         double                            spu,
@@ -128,7 +128,7 @@ RegionView::RegionView (const RegionView& other, boost::shared_ptr<Region> other
 	GhostRegion::CatchDeletion.connect (*this, invalidator (*this), boost::bind (&RegionView::remove_ghost, this, _1), gui_context());
 }
 
-RegionView::RegionView (ArdourCanvas::Group*         parent,
+RegionView::RegionView (ArdourCanvas::Layout*         parent,
                         TimeAxisView&                tv,
                         boost::shared_ptr<ARDOUR::Region> r,
                         double                       spu,
diff --git a/gtk2_ardour/region_view.h b/gtk2_ardour/region_view.h
index e3bc1e6cbf..1c34d29360 100644
--- a/gtk2_ardour/region_view.h
+++ b/gtk2_ardour/region_view.h
@@ -49,7 +49,7 @@ namespace ArdourCanvas {
 class RegionView : public TimeAxisViewItem
 {
   public:
-	RegionView (ArdourCanvas::Group* parent,
+	RegionView (ArdourCanvas::Layout* parent,
 	            TimeAxisView&        time_view,
 	            boost::shared_ptr<ARDOUR::Region> region,
 	            double               samples_per_pixel,
@@ -128,7 +128,7 @@ class RegionView : public TimeAxisViewItem
 	/** Allows derived types to specify their visibility requirements
 	 * to the TimeAxisViewItem parent class
 	 */
-	RegionView (ArdourCanvas::Group *,
+	RegionView (ArdourCanvas::Layout *,
 		    TimeAxisView&,
 		    boost::shared_ptr<ARDOUR::Region>,
 		    double samples_per_pixel,
diff --git a/gtk2_ardour/streamview.cc b/gtk2_ardour/streamview.cc
index 97e3d3aa79..15facc3adf 100644
--- a/gtk2_ardour/streamview.cc
+++ b/gtk2_ardour/streamview.cc
@@ -52,9 +52,9 @@ using namespace ARDOUR;
 using namespace PBD;
 using namespace Editing;
 
-StreamView::StreamView (RouteTimeAxisView& tv, ArdourCanvas::Group* canvas_group)
+StreamView::StreamView (RouteTimeAxisView& tv, ArdourCanvas::Layout* canvas_group)
 	: _trackview (tv)
-	, _canvas_group (canvas_group ? canvas_group : new ArdourCanvas::Group (_trackview.canvas_display()))
+	, _canvas_group (canvas_group ? canvas_group : new ArdourCanvas::Layout (_trackview.canvas_display()))
 	, _samples_per_pixel (_trackview.editor().get_current_zoom ())
 	, rec_updating(false)
 	, rec_active(false)
diff --git a/gtk2_ardour/streamview.h b/gtk2_ardour/streamview.h
index e0d60baf34..7c7bbad924 100644
--- a/gtk2_ardour/streamview.h
+++ b/gtk2_ardour/streamview.h
@@ -42,7 +42,7 @@ namespace ARDOUR {
 
 namespace ArdourCanvas {
 	class Rectangle;
-	class Group;
+	class Layout;
 }
 
 struct RecBoxInfo {
@@ -82,7 +82,7 @@ public:
  	void set_layer_display (LayerDisplay);
 	LayerDisplay layer_display () const { return _layer_display; }
 
-	ArdourCanvas::Group* canvas_item() { return _canvas_group; }
+	ArdourCanvas::Layout* canvas_item() { return _canvas_group; }
 
 	enum ColorTarget {
 		RegionColor,
@@ -128,7 +128,7 @@ public:
 	sigc::signal<void> ContentsHeightChanged;
 
 protected:
-       StreamView (RouteTimeAxisView&, ArdourCanvas::Group* canvas_group = 0);
+       StreamView (RouteTimeAxisView&, ArdourCanvas::Layout* canvas_group = 0);
 
 	void         transport_changed();
 	void         transport_looped();
@@ -151,7 +151,7 @@ protected:
 	virtual void color_handler () = 0;
 
 	RouteTimeAxisView&        _trackview;
-	ArdourCanvas::Group*      _canvas_group;
+	ArdourCanvas::Layout*      _canvas_group;
 	ArdourCanvas::Rectangle*   canvas_rect; /* frame around the whole thing */
 
 	typedef std::list<RegionView* > RegionViewList;
diff --git a/gtk2_ardour/sys_ex.cc b/gtk2_ardour/sys_ex.cc
index 2097de4fa9..103df599ec 100644
--- a/gtk2_ardour/sys_ex.cc
+++ b/gtk2_ardour/sys_ex.cc
@@ -26,7 +26,7 @@ using namespace std;
 
 SysEx::SysEx (
 	MidiRegionView& region,
-	ArdourCanvas::Group* parent,
+	ArdourCanvas::Layout* parent,
 	string&         text,
 	double          height,
 	double          x,
diff --git a/gtk2_ardour/sys_ex.h b/gtk2_ardour/sys_ex.h
index 1d6787a75e..281731e863 100644
--- a/gtk2_ardour/sys_ex.h
+++ b/gtk2_ardour/sys_ex.h
@@ -31,7 +31,7 @@ class SysEx
 public:
 	SysEx (
 			MidiRegionView& region,
-			ArdourCanvas::Group* parent,
+			ArdourCanvas::Layout* parent,
 			std::string&    text,
 			double          height,
 			double          x,
diff --git a/gtk2_ardour/tape_region_view.cc b/gtk2_ardour/tape_region_view.cc
index 62d37a9f7e..6de7b65327 100644
--- a/gtk2_ardour/tape_region_view.cc
+++ b/gtk2_ardour/tape_region_view.cc
@@ -46,7 +46,7 @@ const TimeAxisViewItem::Visibility TapeAudioRegionView::default_tape_visibility
 		TimeAxisViewItem::HideFrameRight |
 		TimeAxisViewItem::FullWidthNameHighlight);
 
-TapeAudioRegionView::TapeAudioRegionView (ArdourCanvas::Group *parent, RouteTimeAxisView &tv,
+TapeAudioRegionView::TapeAudioRegionView (ArdourCanvas::Layout *parent, RouteTimeAxisView &tv,
 					  boost::shared_ptr<AudioRegion> r,
 					  double spu,
 					  uint32_t basic_color)
diff --git a/gtk2_ardour/tape_region_view.h b/gtk2_ardour/tape_region_view.h
index bda41ca8ad..4729328625 100644
--- a/gtk2_ardour/tape_region_view.h
+++ b/gtk2_ardour/tape_region_view.h
@@ -27,7 +27,7 @@
 class TapeAudioRegionView : public AudioRegionView
 {
   public:
-	TapeAudioRegionView (ArdourCanvas::Group *,
+	TapeAudioRegionView (ArdourCanvas::Layout *,
 			     RouteTimeAxisView&,
 			     boost::shared_ptr<ARDOUR::AudioRegion>,
 			     double initial_samples_per_pixel,
diff --git a/gtk2_ardour/tempo_lines.cc b/gtk2_ardour/tempo_lines.cc
index c2f7df1c42..b9686821f8 100644
--- a/gtk2_ardour/tempo_lines.cc
+++ b/gtk2_ardour/tempo_lines.cc
@@ -28,7 +28,7 @@
 
 using namespace std;
 
-TempoLines::TempoLines (ArdourCanvas::Group* group, double)
+TempoLines::TempoLines (ArdourCanvas::Layout* group, double)
 	: lines (group, ArdourCanvas::LineSet::Vertical)
 {
 	lines.set_extent (ArdourCanvas::COORD_MAX);
diff --git a/gtk2_ardour/tempo_lines.h b/gtk2_ardour/tempo_lines.h
index e096df54af..8b64885667 100644
--- a/gtk2_ardour/tempo_lines.h
+++ b/gtk2_ardour/tempo_lines.h
@@ -25,7 +25,7 @@
 
 class TempoLines {
 public:
-	TempoLines (ArdourCanvas::Group* group, double screen_height);
+	TempoLines (ArdourCanvas::Layout* group, double screen_height);
 
 	void tempo_map_changed();
 
diff --git a/gtk2_ardour/time_axis_view.cc b/gtk2_ardour/time_axis_view.cc
index cbd4e32cc6..3478297e58 100644
--- a/gtk2_ardour/time_axis_view.cc
+++ b/gtk2_ardour/time_axis_view.cc
@@ -97,16 +97,16 @@ TimeAxisView::TimeAxisView (ARDOUR::Session* sess, PublicEditor& ed, TimeAxisVie
 		compute_heights ();
 	}
 
-	_canvas_display = new Group (ed.get_trackview_group (), ArdourCanvas::Duple (0.0, 0.0));
+	_canvas_display = new ArdourCanvas::Layout (ed.get_trackview_group (), ArdourCanvas::Duple (0.0, 0.0));
 	CANVAS_DEBUG_NAME (_canvas_display, "main for TAV");
 	_canvas_display->hide(); // reveal as needed
 
-	selection_group = new Group (_canvas_display);
+	selection_group = new ArdourCanvas::Layout (_canvas_display);
 	CANVAS_DEBUG_NAME (selection_group, "selection for TAV");
 	selection_group->set_data (X_("timeselection"), (void *) 1);
 	selection_group->hide();
 	
-	_ghost_group = new Group (_canvas_display);
+	_ghost_group = new ArdourCanvas::Layout (_canvas_display);
 	CANVAS_DEBUG_NAME (_ghost_group, "ghost for TAV");
 	_ghost_group->lower_to_bottom();
 	_ghost_group->show();
diff --git a/gtk2_ardour/time_axis_view.h b/gtk2_ardour/time_axis_view.h
index 38626a080d..cddf9f9e29 100644
--- a/gtk2_ardour/time_axis_view.h
+++ b/gtk2_ardour/time_axis_view.h
@@ -59,7 +59,7 @@ namespace Gtk {
 
 namespace ArdourCanvas {
 	class Canvas;
-	class Group;
+	class Layout;
 	class Item;
 }
 
@@ -104,8 +104,8 @@ class TimeAxisView : public virtual AxisView
         virtual void enter_internal_edit_mode () {}
         virtual void leave_internal_edit_mode () {}
 
-	ArdourCanvas::Group* canvas_display () { return _canvas_display; }
-	ArdourCanvas::Group* ghost_group () { return _ghost_group; }
+	ArdourCanvas::Layout* canvas_display () { return _canvas_display; }
+	ArdourCanvas::Layout* ghost_group () { return _ghost_group; }
 
 	/** @return effective height (taking children into account) in canvas units, or
 	    0 if this TimeAxisView has not yet been shown */
@@ -212,15 +212,15 @@ class TimeAxisView : public virtual AxisView
 	std::string            controls_base_selected_name;
 	Gtk::Menu*             display_menu; /* The standard LHS Track control popup-menus */
 	TimeAxisView*          parent;
-	ArdourCanvas::Group*   selection_group;
-	ArdourCanvas::Group*  _ghost_group;
+	ArdourCanvas::Layout*   selection_group;
+	ArdourCanvas::Layout*  _ghost_group;
 	std::list<GhostRegion*> ghosts;
 	std::list<SelectionRect*> free_selection_rects;
 	std::list<SelectionRect*> used_selection_rects;
 	bool                  _hidden;
 	bool                   in_destructor;
 	Gtk::Menu*            _size_menu;
-	ArdourCanvas::Group*  _canvas_display;
+	ArdourCanvas::Layout*  _canvas_display;
 	double                _y_position;
 	PublicEditor&         _editor;
 
diff --git a/gtk2_ardour/time_axis_view_item.cc b/gtk2_ardour/time_axis_view_item.cc
index 1e1e66889f..4494b9b265 100644
--- a/gtk2_ardour/time_axis_view_item.cc
+++ b/gtk2_ardour/time_axis_view_item.cc
@@ -28,7 +28,7 @@
 #include "gtkmm2ext/utils.h"
 #include "gtkmm2ext/gui_thread.h"
 
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/rectangle.h"
 #include "canvas/debug.h"
 #include "canvas/text.h"
@@ -119,7 +119,7 @@ TimeAxisViewItem::set_constant_heights ()
  * @param automation true if this is an automation region view
  */
 TimeAxisViewItem::TimeAxisViewItem(
-	const string & it_name, ArdourCanvas::Group& parent, TimeAxisView& tv, double spu, uint32_t base_color,
+	const string & it_name, ArdourCanvas::Item& parent, TimeAxisView& tv, double spu, uint32_t base_color,
 	framepos_t start, framecnt_t duration, bool recording, bool automation, Visibility vis
 	)
 	: trackview (tv)
@@ -149,7 +149,7 @@ TimeAxisViewItem::TimeAxisViewItem (const TimeAxisViewItem& other)
 {
 	/* share the other's parent, but still create a new group */
 
-	ArdourCanvas::Group* parent = other.group->parent();
+	ArdourCanvas::Item* parent = other.group->parent();
 	
 	_selected = other._selected;
 	
@@ -158,11 +158,11 @@ TimeAxisViewItem::TimeAxisViewItem (const TimeAxisViewItem& other)
 }
 
 void
-TimeAxisViewItem::init (ArdourCanvas::Group* parent, double fpp, uint32_t base_color, 
+TimeAxisViewItem::init (ArdourCanvas::Item* parent, double fpp, uint32_t base_color, 
 			framepos_t start, framepos_t duration, Visibility vis, 
 			bool wide, bool high)
 {
-	group = new ArdourCanvas::Group (parent);
+	group = new ArdourCanvas::Layout (parent);
 	CANVAS_DEBUG_NAME (group, string_compose ("TAVI group for %1", get_item_name()));
 	group->Event.connect (sigc::mem_fun (*this, &TimeAxisViewItem::canvas_group_event));
 
@@ -646,7 +646,7 @@ TimeAxisViewItem::get_canvas_frame()
 	return frame;
 }
 
-ArdourCanvas::Group*
+ArdourCanvas::Item*
 TimeAxisViewItem::get_canvas_group()
 {
 	return group;
diff --git a/gtk2_ardour/time_axis_view_item.h b/gtk2_ardour/time_axis_view_item.h
index 04072d1a8e..388aa43b7a 100644
--- a/gtk2_ardour/time_axis_view_item.h
+++ b/gtk2_ardour/time_axis_view_item.h
@@ -33,8 +33,8 @@ namespace ArdourCanvas {
 	class Pixbuf;
 	class Rectangle;
 	class Item;
-	class Group;
-	class Text;
+        class Layout;
+ 	class Text;
 }
 
 using ARDOUR::framepos_t;
@@ -79,7 +79,7 @@ class TimeAxisViewItem : public Selectable, public PBD::ScopedConnectionList
         uint32_t get_fill_color () const;
 
 	ArdourCanvas::Item* get_canvas_frame();
-	ArdourCanvas::Group* get_canvas_group();
+	ArdourCanvas::Item* get_canvas_group();
 	ArdourCanvas::Item* get_name_highlight();
 
 	virtual void set_samples_per_pixel (double);
@@ -170,12 +170,12 @@ class TimeAxisViewItem : public Selectable, public PBD::ScopedConnectionList
 	};
 
   protected:
-	TimeAxisViewItem (const std::string &, ArdourCanvas::Group&, TimeAxisView&, double, uint32_t fill_color,
+	TimeAxisViewItem (const std::string &, ArdourCanvas::Item&, TimeAxisView&, double, uint32_t fill_color,
 			  framepos_t, framecnt_t, bool recording = false, bool automation = false, Visibility v = Visibility (0));
 
 	TimeAxisViewItem (const TimeAxisViewItem&);
 
-        void init (ArdourCanvas::Group*, double, uint32_t, framepos_t, framepos_t, Visibility, bool, bool);
+        void init (ArdourCanvas::Item*, double, uint32_t, framepos_t, framepos_t, Visibility, bool, bool);
 
         virtual bool canvas_group_event (GdkEvent*);
 
@@ -240,7 +240,7 @@ class TimeAxisViewItem : public Selectable, public PBD::ScopedConnectionList
 	bool high_enough_for_name;
         bool rect_visible;
 
-	ArdourCanvas::Group*      group;
+	ArdourCanvas::Layout*      group;
 	ArdourCanvas::Rectangle* vestigial_frame;
 	ArdourCanvas::Rectangle* frame;
 	ArdourCanvas::Text*      name_text;
diff --git a/gtk2_ardour/verbose_cursor.cc b/gtk2_ardour/verbose_cursor.cc
index d6f89bde2b..abe145d4bf 100644
--- a/gtk2_ardour/verbose_cursor.cc
+++ b/gtk2_ardour/verbose_cursor.cc
@@ -23,6 +23,7 @@
 #include "ardour/profile.h"
 
 #include "canvas/debug.h"
+#include "canvas/scroll_group.h"
 
 #include "ardour_ui.h"
 #include "audio_clock.h"
diff --git a/gtk2_ardour/video_image_frame.cc b/gtk2_ardour/video_image_frame.cc
index 1ae69f02e1..861c763665 100644
--- a/gtk2_ardour/video_image_frame.cc
+++ b/gtk2_ardour/video_image_frame.cc
@@ -24,7 +24,7 @@
 #include "video_image_frame.h"
 #include "public_editor.h"
 #include "utils.h"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "utils_videotl.h"
 
 #include <gtkmm2ext/utils.h>
@@ -43,7 +43,7 @@ static void freedata_cb (uint8_t *d, void* /*arg*/) {
 	free (d);
 }
 
-VideoImageFrame::VideoImageFrame (PublicEditor& ed, ArdourCanvas::Group& parent, int w, int h, std::string vsurl, std::string vfn)
+VideoImageFrame::VideoImageFrame (PublicEditor& ed, ArdourCanvas::Layout& parent, int w, int h, std::string vsurl, std::string vfn)
 	: editor (ed)
 	, _parent(&parent)
 	, clip_width(w)
diff --git a/gtk2_ardour/video_image_frame.h b/gtk2_ardour/video_image_frame.h
index b611ff0d9e..cbe3a8da91 100644
--- a/gtk2_ardour/video_image_frame.h
+++ b/gtk2_ardour/video_image_frame.h
@@ -32,7 +32,7 @@
 #include "ardour/ardour.h"
 #include "pbd/signals.h"
 
-#include "canvas/group.h"
+#include "canvas/layout.h"
 #include "canvas/pixbuf.h"
 #include "canvas/image.h"
 
@@ -49,7 +49,7 @@ class PublicEditor;
 class VideoImageFrame : public sigc::trackable
 {
 	public:
-	VideoImageFrame (PublicEditor&, ArdourCanvas::Group&, int, int, std::string, std::string);
+	VideoImageFrame (PublicEditor&, ArdourCanvas::Layout&, int, int, std::string, std::string);
 	virtual ~VideoImageFrame ();
 
 	void set_position (framepos_t);
@@ -69,7 +69,7 @@ class VideoImageFrame : public sigc::trackable
 	protected:
 
 	PublicEditor& editor;
-	ArdourCanvas::Group *_parent;
+	ArdourCanvas::Layout *_parent;
 	ArdourCanvas::Image *image;
 	boost::shared_ptr<ArdourCanvas::Image::Data> img;
 
diff --git a/gtk2_ardour/video_timeline.cc b/gtk2_ardour/video_timeline.cc
index 72b0dff654..180876b0ed 100644
--- a/gtk2_ardour/video_timeline.cc
+++ b/gtk2_ardour/video_timeline.cc
@@ -51,7 +51,7 @@ using namespace PBD;
 using namespace Timecode;
 using namespace VideoUtils;
 
-VideoTimeLine::VideoTimeLine (PublicEditor *ed, ArdourCanvas::Group *vbg, int initial_height)
+VideoTimeLine::VideoTimeLine (PublicEditor *ed, ArdourCanvas::Layout *vbg, int initial_height)
 	: editor (ed)
 		, videotl_group(vbg)
 		, bar_height(initial_height)
diff --git a/gtk2_ardour/video_timeline.h b/gtk2_ardour/video_timeline.h
index f84e613cc8..55384f4836 100644
--- a/gtk2_ardour/video_timeline.h
+++ b/gtk2_ardour/video_timeline.h
@@ -29,7 +29,7 @@
 #include "video_image_frame.h"
 #include "video_monitor.h"
 #include "pbd/signals.h"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 
 namespace ARDOUR {
 	class Session;
@@ -55,7 +55,7 @@ class PublicEditor;
 class VideoTimeLine : public sigc::trackable, public ARDOUR::SessionHandlePtr, public PBD::ScopedConnectionList, public PBD::StatefulDestructible
 {
 	public:
-	VideoTimeLine (PublicEditor*, ArdourCanvas::Group*, int);
+	VideoTimeLine (PublicEditor*, ArdourCanvas::Layout*, int);
 	virtual ~VideoTimeLine ();
 
 	void set_session (ARDOUR::Session *s);
@@ -102,7 +102,7 @@ class VideoTimeLine : public sigc::trackable, public ARDOUR::SessionHandlePtr, p
 	protected:
 
 	PublicEditor *editor;
-	ArdourCanvas::Group *videotl_group;
+	ArdourCanvas::Layout *videotl_group;
 	int bar_height;
 
 	std::string _xjadeo_bin;