change Canvas heirarchy and constructors

Items no longer need a parent group (they require a Canvas pointer instead), so all constructors have been rationalized
and have two variants, one with a parent and one with a canvas.

All Items now inherit from Fill and Outline, to banish diagonal inheritance and virtual base classes and all that.

There were zero changes to the Ardour GUI arising from these changes.

1 files changed, 59 insertions, 28 deletions

diff --git a/libs/canvas/item.cc b/libs/canvas/item.cc
index 2bca2feac2..53dca5d976 100644
--- a/libs/canvas/item.cc
+++ b/libs/canvas/item.cc
@@ -34,41 +34,53 @@ using namespace PBD;
 using namespace ArdourCanvas;
 
 Item::Item (Canvas* canvas)
-	: _canvas (canvas)
+	: Fill (*this)
+	, Outline (*this)
+	,  _canvas (canvas)
 	, _parent (0)
+	, _visible (true)
+	, _bounding_box_dirty (true)
+	, _ignore_events (false)
 {
-	init ();
-}
+	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));
+}	
 
 Item::Item (Group* parent)
-	: _canvas (parent->canvas ())
+	: Fill (*this)
+	, Outline (*this)
+	,  _canvas (parent->canvas())
 	, _parent (parent)
+	, _visible (true)
+	, _bounding_box_dirty (true)
+	, _ignore_events (false)
 {
-	init ();
-}
+	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));
+
+	if (parent) {
+		_parent->add (this);
+	}
+
+	find_scroll_parent ();
+}	
 
-Item::Item (Group* parent, Duple position)
-	: _canvas (parent->canvas())
+Item::Item (Group* parent, Duple const& p)
+	: Fill (*this)
+	, Outline (*this)
+	,  _canvas (parent->canvas())
 	, _parent (parent)
-	, _position (position)
+	, _position (p)
+	, _visible (true)
+	, _bounding_box_dirty (true)
+	, _ignore_events (false)
 {
-	init ();
-}
+	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));
 
-void
-Item::init ()
-{
-	_visible = true;
-	_bounding_box_dirty = true;
-	_ignore_events = false;
-	
-	if (_parent) {
+	if (parent) {
 		_parent->add (this);
 	}
 
 	find_scroll_parent ();
 
-	DEBUG_TRACE (DEBUG::CanvasItems, string_compose ("new canvas item %1\n", this));
 }	
 
 Item::~Item ()
@@ -98,7 +110,7 @@ Item::window_origin () const
 	if (_parent) {
 		return _parent->item_to_window (_position);
 	} else {
-		return _parent->item_to_window (Duple (0,0));
+		return _position;
 	}
 }
 
@@ -254,22 +266,25 @@ Item::set_y_position (Coord y)
 void
 Item::raise_to_top ()
 {
-	assert (_parent);
-	_parent->raise_child_to_top (this);
+	if (_parent) {
+		_parent->raise_child_to_top (this);
+	}
 }
 
 void
 Item::raise (int levels)
 {
-	assert (_parent);
-	_parent->raise_child (this, levels);
+	if (_parent) {
+		_parent->raise_child (this, levels);
+	}
 }
 
 void
 Item::lower_to_bottom ()
 {
-	assert (_parent);
-	_parent->lower_child_to_bottom (this);
+	if (_parent) {
+		_parent->lower_child_to_bottom (this);
+	}
 }
 
 void
@@ -318,7 +333,11 @@ Item::unparent ()
 void
 Item::reparent (Group* new_parent)
 {
-	assert (_canvas == _parent->canvas());
+	if (new_parent == _parent) {
+		return;
+	}
+
+	assert (_canvas == new_parent->canvas());
 
 	if (_parent) {
 		_parent->remove (this);
@@ -370,10 +389,16 @@ Item::common_ancestor_within (uint32_t limit, const Item& other) const
 
 	while (d1 != d2) {
 		if (d1 > d2) {
+			if (!i1) {
+				return false;
+			}
 			i1 = i1->parent();
 			d1--;
 			limit--;
 		} else {
+			if (!i2) {
+				return false;
+			}
 			i2 = i2->parent();
 			d2--;
 			limit--;
@@ -416,9 +441,15 @@ Item::closest_ancestor_with (const Item& other) const
 
 	while (d1 != d2) {
 		if (d1 > d2) {
+			if (!i1) {
+				return 0;
+			}
 			i1 = i1->parent();
 			d1--;
 		} else {
+			if (!i2) {
+				return 0;
+			}
 			i2 = i2->parent();
 			d2--;
 		}