refactor Canvas so that all Items have children; add Container abstract base class; rename Group as "Layout" and retain only drawing semantics

26 files changed, 81 insertions, 135 deletions

diff --git a/libs/canvas/canvas/arc.h b/libs/canvas/canvas/arc.h
index 5eaa4a0ab9..c2b32d9e10 100644
--- a/libs/canvas/canvas/arc.h
+++ b/libs/canvas/canvas/arc.h
@@ -32,7 +32,7 @@ class LIBCANVAS_API Arc : public Item
 {
 public:
 	Arc (Canvas*);
-	Arc (Group*);
+	Arc (Item*);
 
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
 	void compute_bounding_box () const;
diff --git a/libs/canvas/canvas/arrow.h b/libs/canvas/canvas/arrow.h
index 75c21da07c..7db225553e 100644
--- a/libs/canvas/canvas/arrow.h
+++ b/libs/canvas/canvas/arrow.h
@@ -26,8 +26,7 @@
 #define __CANVAS_ARROW_H__
 
 #include "canvas/visibility.h"
-
-#include "canvas/group.h"
+#include "canvas/layout.h"
 
 namespace ArdourCanvas {
 
@@ -46,11 +45,11 @@ class Polygon;
  *  to draw lines at any angle.
  */
 	
-class LIBCANVAS_API Arrow : public Group
+class LIBCANVAS_API Arrow : public Layout
 {
 public:
 	Arrow (Canvas*);
-	Arrow (Group*);
+	Arrow (Item*);
 
 	void set_show_head (int, bool);
 	void set_head_outward (int, bool);
diff --git a/libs/canvas/canvas/canvas.h b/libs/canvas/canvas/canvas.h
index fac9367985..94005f4cc7 100644
--- a/libs/canvas/canvas/canvas.h
+++ b/libs/canvas/canvas/canvas.h
@@ -42,7 +42,7 @@ namespace ArdourCanvas
 {
 
 class Rect;
-class Group;	
+class Item;
 class ScrollGroup;
 
 /** The base class for our different types of canvas.
@@ -78,7 +78,7 @@ public:
 	void render (Rect const &, Cairo::RefPtr<Cairo::Context> const &) const;
 
 	/** @return root group */
-	Group* root () {
+	Item* root () {
 		return &_root;
 	}
 
@@ -122,8 +122,8 @@ public:
 protected:
 	void queue_draw_item_area (Item *, Rect);
 	
-	/** our root group */
-	RootGroup _root;
+	/** our root item */
+	Root _root;
 
         virtual void pick_current_item (int state) = 0;
         virtual void pick_current_item (Duple const &, int state) = 0;
diff --git a/libs/canvas/canvas/circle.h b/libs/canvas/canvas/circle.h
index 1ca376a7a2..c84e3aceec 100644
--- a/libs/canvas/canvas/circle.h
+++ b/libs/canvas/canvas/circle.h
@@ -29,7 +29,7 @@ class LIBCANVAS_API Circle : public Arc
 {
   public:
 	Circle (Canvas*);
-	Circle (Group*);
+	Circle (Item*);
 };
 	
 }
diff --git a/libs/canvas/canvas/curve.h b/libs/canvas/canvas/curve.h
index 1bcab58e32..d27291e353 100644
--- a/libs/canvas/canvas/curve.h
+++ b/libs/canvas/canvas/curve.h
@@ -33,7 +33,7 @@ class LIBCANVAS_API Curve : public PolyItem, public InterpolatedCurve
 {
   public:
     Curve (Canvas*);
-    Curve (Group*);
+    Curve (Item*);
 
     enum CurveFill {
 	    None,
diff --git a/libs/canvas/canvas/flag.h b/libs/canvas/canvas/flag.h
index 2429e1775e..05c0e2777d 100644
--- a/libs/canvas/canvas/flag.h
+++ b/libs/canvas/canvas/flag.h
@@ -18,8 +18,8 @@
 */
 
 #include "canvas/visibility.h"
-#include "canvas/group.h"
 #include "canvas/types.h"
+#include "canvas/layout.h"
 
 namespace ArdourCanvas {
 
@@ -27,11 +27,11 @@ class Text;
 class Line;
 class Rectangle;
 
-class LIBCANVAS_API Flag : public Group
+class LIBCANVAS_API Flag : public Layout
 {
 public:
 	Flag (Canvas *, Distance, Color, Color, Duple);
-	Flag (Group*, Distance, Color, Color, Duple);
+	Flag (Item*, Distance, Color, Color, Duple);
 
 	void set_text (std::string const &);
 	void set_height (Distance);
diff --git a/libs/canvas/canvas/fwd.h b/libs/canvas/canvas/fwd.h
index 728e6988d4..61cab3c9d2 100644
--- a/libs/canvas/canvas/fwd.h
+++ b/libs/canvas/canvas/fwd.h
@@ -33,6 +33,7 @@ namespace ArdourCanvas {
 	class GtkCanvasViewport;
 	class Text;
 	class Curve;
+        class ScrollGroup;
 }
 
 #endif /* __canvas_canvas_fwd_h__ */
diff --git a/libs/canvas/canvas/group.h b/libs/canvas/canvas/group.h
deleted file mode 100644
index 6bfc40ba28..0000000000
--- a/libs/canvas/canvas/group.h
+++ /dev/null
@@ -1,79 +0,0 @@
-/*
-    Copyright (C) 2011-2013 Paul Davis
-    Author: Carl Hetherington <cth@carlh.net>
-
-    This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#ifndef __CANVAS_GROUP_H__
-#define __CANVAS_GROUP_H__
-
-#include <list>
-#include <vector>
-
-#include "canvas/visibility.h"
-#include "canvas/item.h"
-#include "canvas/types.h"
-#include "canvas/lookup_table.h"
-
-namespace ArdourCanvas {
-
-class LIBCANVAS_API Group : public Item
-{
-public:
-	Group (Canvas*);
-	Group (Group*);
-	Group (Group*, Duple const& positon);
-	virtual ~Group ();
-
-	void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
-	virtual void compute_bounding_box () const;
-
-	void add (Item *);
-	void remove (Item *);
-         void clear (bool with_delete = false);
-	std::list<Item*> const & items () const {
-		return _items;
-	}
-
-	void raise_child_to_top (Item *);
-	void raise_child (Item *, int);
-	void lower_child_to_bottom (Item *);
-	void child_changed ();
-	
-	void scroll_to (Duple const& d);
-	
-	void add_items_at_point (Duple, std::vector<Item const *> &) const;
-
-        void dump (std::ostream&) const;
-
-	static int default_items_per_cell;
-
-private:
-	friend class ::OptimizingLookupTableTest;
-	
-	void ensure_lut () const;
-	void invalidate_lut () const;
-	void clear_items (bool with_delete);
-
-	/* our items, from lowest to highest in the stack */
-	std::list<Item*> _items;
-
-	mutable LookupTable* _lut;
-};
-
-}
-
-#endif
diff --git a/libs/canvas/canvas/image.h b/libs/canvas/canvas/image.h
index fd86818c21..64d70a5751 100644
--- a/libs/canvas/canvas/image.h
+++ b/libs/canvas/canvas/image.h
@@ -35,7 +35,7 @@ class LIBCANVAS_API Image : public Item
 {
 public:
     Image (Canvas *, Cairo::Format, int width, int height);
-    Image (Group*, Cairo::Format, int width, int height);
+    Image (Item*, Cairo::Format, int width, int height);
     
     struct Data {
 	Data (uint8_t *d, int w, int h, int s, Cairo::Format fmt)
diff --git a/libs/canvas/canvas/item.h b/libs/canvas/canvas/item.h
index bf752f66db..ced94e1e3b 100644
--- a/libs/canvas/canvas/item.h
+++ b/libs/canvas/canvas/item.h
@@ -32,12 +32,12 @@
 #include "canvas/types.h"
 #include "canvas/fill.h"
 #include "canvas/outline.h"
+#include "canvas/lookup_table.h"
 
 namespace ArdourCanvas
 {
 
 class Canvas;
-class Group;
 class Rect;	
 class ScrollGroup;
 
@@ -56,8 +56,8 @@ class LIBCANVAS_API Item : public Fill, public Outline
 {
 public:
 	Item (Canvas *);
-	Item (Group *);
-	Item (Group *, Duple const& p);
+	Item (Item *);
+	Item (Item *, Duple const& p);
 	virtual ~Item ();
 
         void redraw () const;
@@ -80,13 +80,11 @@ public:
 	 *
 	 * Note that Item::add_items_at_window_point() is only intended to be 
 	 * called on items already looked up in a LookupTable (i.e. by a
-	 * parent group) and thus known to cover @param point already.
+	 * parent) and thus known to cover @param point already.
 	 *
-	 * Derived classes may add more items than themselves (e.g. Group).
+	 * Derived classes may add more items than themselves (e.g. containers).
 	 */
-	virtual void add_items_at_point (Duple /*point*/, std::vector<Item const *>& items) const {
-		items.push_back (this);
-	}
+	virtual void add_items_at_point (Duple /*point*/, std::vector<Item const *>& items) const;
 
         virtual bool covers (Duple const &) const;
 
@@ -97,10 +95,10 @@ public:
 	void ungrab ();
 	
 	void unparent ();
-	void reparent (Group *);
+	void reparent (Item *);
 
 	/** @return Parent group, or 0 if this is the root group */
-	Group* parent () const {
+	Item* parent () const {
 		return _parent;
 	}
     
@@ -124,8 +122,6 @@ public:
 	void set_y_position (Coord);
 	void move (Duple);
 
-	virtual void scroll_to (Duple const&) {}
-
 	/** @return Position of this item in the parent's coordinates */
 	Duple position () const {
 		return _position;
@@ -187,6 +183,21 @@ public:
 
 	void set_data (std::string const &, void *);
 	void* get_data (std::string const &) const;
+
+	/* nested item ("grouping") API */
+	void add (Item *);
+	void remove (Item *);
+        void clear (bool with_delete = false);
+	std::list<Item*> const & items () const {
+		return _items;
+	}
+	void raise_child_to_top (Item *);
+	void raise_child (Item *, int);
+	void lower_child_to_bottom (Item *);
+	void child_changed ();
+
+	static int default_items_per_cell;
+
 	
 	/* This is a sigc++ signal because it is solely
 	   concerned with GUI stuff and is thus single-threaded
@@ -243,7 +254,7 @@ protected:
 
 	Canvas* _canvas;
 	/** parent group; may be 0 if we are the root group or if we have been unparent()ed */
-	Group* _parent;
+	Item* _parent;
 	/** scroll parent group; may be 0 if we are the root group or if we have been unparent()ed */
 	ScrollGroup* _scroll_parent;
 	/** position of this item in parent coordinates */
@@ -261,6 +272,18 @@ protected:
 	/* XXX: this is a bit grubby */
 	std::map<std::string, void *> _data;
 
+	/* nesting ("grouping") API */
+
+	void invalidate_lut () const;
+	void clear_items (bool with_delete);
+
+	void ensure_lut () const;
+	mutable LookupTable* _lut;
+	/* our items, from lowest to highest in the stack */
+	std::list<Item*> _items;
+
+	void add_child_bounding_boxes() const;
+
 private:
 	void init ();
 
diff --git a/libs/canvas/canvas/line.h b/libs/canvas/canvas/line.h
index e8f57a00ba..b178554c84 100644
--- a/libs/canvas/canvas/line.h
+++ b/libs/canvas/canvas/line.h
@@ -31,7 +31,7 @@ class LIBCANVAS_API Line : public Item
 {
   public:
 	Line (Canvas*);
-	Line (Group*);
+	Line (Item*);
 
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
 	void compute_bounding_box () const;
diff --git a/libs/canvas/canvas/line_set.h b/libs/canvas/canvas/line_set.h
index 38f97250ce..fad100fdf9 100644
--- a/libs/canvas/canvas/line_set.h
+++ b/libs/canvas/canvas/line_set.h
@@ -36,7 +36,7 @@ public:
 	};
 
 	LineSet (Canvas*, Orientation o = Vertical);
-	LineSet (Group*, Orientation o = Vertical);
+	LineSet (Item*, Orientation o = Vertical);
 
 	void compute_bounding_box () const;
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
diff --git a/libs/canvas/canvas/lookup_table.h b/libs/canvas/canvas/lookup_table.h
index 5be33c1bca..29452365cd 100644
--- a/libs/canvas/canvas/lookup_table.h
+++ b/libs/canvas/canvas/lookup_table.h
@@ -31,12 +31,11 @@ class OptimizingLookupTableTest;
 namespace ArdourCanvas {
 
 class Item;
-class Group;
 
 class LIBCANVAS_API LookupTable
 {
 public:
-    LookupTable (Group const &);
+    LookupTable (Item const &);
     virtual ~LookupTable ();
     
     virtual std::vector<Item*> get (Rect const &) = 0;
@@ -45,13 +44,13 @@ public:
 
 protected:
 	
-    Group const & _group;
+    Item const & _item;
 };
 
 class LIBCANVAS_API DumbLookupTable : public LookupTable
 {
 public:
-    DumbLookupTable (Group const &);
+	DumbLookupTable (Item const &);
     
     std::vector<Item*> get (Rect const &);
     std::vector<Item*> items_at_point (Duple const &) const;
@@ -61,7 +60,7 @@ public:
 class LIBCANVAS_API OptimizingLookupTable : public LookupTable
 {
 public:
-    OptimizingLookupTable (Group const &, int);
+    OptimizingLookupTable (Item const &, int);
     ~OptimizingLookupTable ();
     std::vector<Item*> get (Rect const &);
     std::vector<Item*> items_at_point (Duple const &) const;
diff --git a/libs/canvas/canvas/pixbuf.h b/libs/canvas/canvas/pixbuf.h
index eba73e57bf..2749b96668 100644
--- a/libs/canvas/canvas/pixbuf.h
+++ b/libs/canvas/canvas/pixbuf.h
@@ -35,7 +35,7 @@ class LIBCANVAS_API Pixbuf : public Item
 {
 public:
 	Pixbuf (Canvas*);
-	Pixbuf (Group*);
+	Pixbuf (Item*);
 
 	void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
 	void compute_bounding_box () const;
diff --git a/libs/canvas/canvas/poly_item.h b/libs/canvas/canvas/poly_item.h
index ab68204ff0..732adb14b3 100644
--- a/libs/canvas/canvas/poly_item.h
+++ b/libs/canvas/canvas/poly_item.h
@@ -30,7 +30,7 @@ class LIBCANVAS_API PolyItem : public Item
 {
 public:
 	PolyItem (Canvas*);
-	PolyItem (Group*);
+	PolyItem (Item*);
 
 	void compute_bounding_box () const;
 
diff --git a/libs/canvas/canvas/poly_line.h b/libs/canvas/canvas/poly_line.h
index 5476711e97..16db9a69e2 100644
--- a/libs/canvas/canvas/poly_line.h
+++ b/libs/canvas/canvas/poly_line.h
@@ -30,7 +30,7 @@ class LIBCANVAS_API PolyLine : public PolyItem
 {
   public:
 	PolyLine (Canvas*);
-	PolyLine (Group*);
+	PolyLine (Item*);
 	
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
 	
diff --git a/libs/canvas/canvas/polygon.h b/libs/canvas/canvas/polygon.h
index a3eed37cdc..9703eb46e9 100644
--- a/libs/canvas/canvas/polygon.h
+++ b/libs/canvas/canvas/polygon.h
@@ -31,7 +31,7 @@ class LIBCANVAS_API Polygon : public PolyItem
 {
 public:
 	Polygon (Canvas*);
-	Polygon (Group*);
+	Polygon (Item*);
         virtual ~Polygon();
 
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
diff --git a/libs/canvas/canvas/rectangle.h b/libs/canvas/canvas/rectangle.h
index ff6eca3cd9..2983d33ed2 100644
--- a/libs/canvas/canvas/rectangle.h
+++ b/libs/canvas/canvas/rectangle.h
@@ -34,8 +34,8 @@ class LIBCANVAS_API Rectangle : public Item
 public:
 	Rectangle (Canvas*);
 	Rectangle (Canvas*, Rect const &);
-	Rectangle (Group*);
-	Rectangle (Group*, Rect const &);
+	Rectangle (Item*);
+	Rectangle (Item*, Rect const &);
 	
 	void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
 	void compute_bounding_box () const;
diff --git a/libs/canvas/canvas/root_group.h b/libs/canvas/canvas/root_group.h
index 70c3e5b90b..5db8024f51 100644
--- a/libs/canvas/canvas/root_group.h
+++ b/libs/canvas/canvas/root_group.h
@@ -21,19 +21,18 @@
 #define __CANVAS_ROOT_GROUP_H__
 
 #include "canvas/visibility.h"
-#include "canvas/group.h"
+#include "canvas/layout.h"
 
 namespace ArdourCanvas {
 
-class LIBCANVAS_API RootGroup : public Group
+class LIBCANVAS_API Root : public Layout
 {
 private:
 	friend class Canvas;
 	
-	RootGroup (Canvas *);
+	Root (Canvas *);
 
 	void compute_bounding_box () const;
-	void child_changed ();
 };
 
 }
diff --git a/libs/canvas/canvas/ruler.h b/libs/canvas/canvas/ruler.h
index 633a1d569e..25040247c9 100644
--- a/libs/canvas/canvas/ruler.h
+++ b/libs/canvas/canvas/ruler.h
@@ -57,8 +57,8 @@ public:
 	
 	Ruler (Canvas*, const Metric& m);
 	Ruler (Canvas*, const Metric& m, Rect const&);
-	Ruler (Group*, const Metric& m);
-	Ruler (Group*, const Metric& m, Rect const&);
+	Ruler (Item*, const Metric& m);
+	Ruler (Item*, const Metric& m, Rect const&);
 	
 	void set_range (double lower, double upper);
 	void set_font_description (Pango::FontDescription);
diff --git a/libs/canvas/canvas/scroll_group.h b/libs/canvas/canvas/scroll_group.h
index 552538eb21..013d769c2f 100644
--- a/libs/canvas/canvas/scroll_group.h
+++ b/libs/canvas/canvas/scroll_group.h
@@ -19,11 +19,15 @@
 #ifndef __CANVAS_SCROLL_GROUP_H__
 #define __CANVAS_SCROLL_GROUP_H__
 
-#include "canvas/group.h"
+#include "canvas/layout.h"
 
 namespace ArdourCanvas {
 
-class LIBCANVAS_API ScrollGroup : public Group
+/** A ScrollGroup has no contents of its own, but renders
+ *  its children in a way that reflects the most recent
+ *  call to its scroll_to() method.
+ */
+class LIBCANVAS_API ScrollGroup : public Layout
 {
   public:
 	enum ScrollSensitivity {
@@ -32,7 +36,7 @@ class LIBCANVAS_API ScrollGroup : public Group
 	};
 	
 	ScrollGroup (Canvas*, ScrollSensitivity);
-	ScrollGroup (Group*, ScrollSensitivity);
+	ScrollGroup (Item*, ScrollSensitivity);
 
 	void scroll_to (Duple const& d);
 	Duple scroll_offset() const { return _scroll_offset; }
diff --git a/libs/canvas/canvas/stateful_image.h b/libs/canvas/canvas/stateful_image.h
index 5952752e71..7c00b0c5a4 100644
--- a/libs/canvas/canvas/stateful_image.h
+++ b/libs/canvas/canvas/stateful_image.h
@@ -50,7 +50,7 @@ class StatefulImage : public Item
   public:
 
     StatefulImage (Canvas*, const XMLNode&);
-    StatefulImage (Group*, const XMLNode&);
+    StatefulImage (Item*, const XMLNode&);
     ~StatefulImage ();
 
     bool set_state (States::size_type);
diff --git a/libs/canvas/canvas/text.h b/libs/canvas/canvas/text.h
index cc6d5c815d..85262ee984 100644
--- a/libs/canvas/canvas/text.h
+++ b/libs/canvas/canvas/text.h
@@ -32,7 +32,7 @@ class LIBCANVAS_API Text : public Item
 {
 public:
 	Text (Canvas*);
-	Text (Group*);
+	Text (Item*);
        ~Text();
 
 	void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
diff --git a/libs/canvas/canvas/wave_view.h b/libs/canvas/canvas/wave_view.h
index c98c62c7a3..042414e1e2 100644
--- a/libs/canvas/canvas/wave_view.h
+++ b/libs/canvas/canvas/wave_view.h
@@ -92,7 +92,7 @@ public:
 
 
 	WaveView (Canvas *, boost::shared_ptr<ARDOUR::AudioRegion>);
-	WaveView (Group*, boost::shared_ptr<ARDOUR::AudioRegion>);
+	WaveView (Item*, boost::shared_ptr<ARDOUR::AudioRegion>);
        ~WaveView ();
 
 	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
diff --git a/libs/canvas/canvas/widget.h b/libs/canvas/canvas/widget.h
index 842f336a51..590bb3af7d 100644
--- a/libs/canvas/canvas/widget.h
+++ b/libs/canvas/canvas/widget.h
@@ -32,7 +32,7 @@ class LIBCANVAS_API Widget : public Item
 {
 public:
 	Widget (Canvas*, CairoWidget&);
-	Widget (Group*, CairoWidget&);
+	Widget (Item*, CairoWidget&);
 	
 	void render (Rect const &, Cairo::RefPtr<Cairo::Context>) const;
 	void compute_bounding_box () const;
diff --git a/libs/canvas/canvas/xfade_curve.h b/libs/canvas/canvas/xfade_curve.h
index d6a10d1f86..c63e47c583 100644
--- a/libs/canvas/canvas/xfade_curve.h
+++ b/libs/canvas/canvas/xfade_curve.h
@@ -36,8 +36,8 @@ public:
 
 	XFadeCurve (Canvas *);
 	XFadeCurve (Canvas *, XFadePosition);
-	XFadeCurve (Group*);
-	XFadeCurve (Group*, XFadePosition);
+	XFadeCurve (Item*);
+	XFadeCurve (Item*, XFadePosition);
 
 	void set_fade_position (XFadePosition xfp) { _xfadeposition = xfp; }