Better applying of transformations

sugar/scene/Actor.py

@@ -1,17 +1,47 @@
-class Actor:
+import gobject
+
+from sugar.scene.Transformation import Transformation
+
+class Actor(gobject.GObject):
+	__gsignals__ = {
+		'changed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE, ())
+	}
+
 	def __init__(self):
+		gobject.GObject.__init__(self)
+
+		self._parent = None
 		self._x = 0
 		self._y = 0
 		self._width = -1
 		self._height = -1
+		self._transf = Transformation()
 
 	def set_position(self, x, y):
 		self._x = x
 		self._y = y
 
+	def _get_parents(self):
+		parents = []
+		parent = self._parent
+		while parent:
+			parents.insert(0, parent)
+			parent = parent._parent
+		return parents
+
+	def _get_abs_position(self, x, y):
+		transf = None
+		parents = self._get_parents()
+		for actor in parents:
+			if transf:
+				transf = transf.compose(actor._transf)
+			else:
+				transf = actor._transf
+		return transf.get_position(x, y)
+
 	def set_size(self, width, height):
 		self._width = width
 		self._height = height
 
-	def render(self, window, transf):
+	def render(self, drawable):
 		pass

sugar/scene/Group.py

@@ -1,17 +1,18 @@
 from sugar.scene.Actor import Actor
-from sugar.scene.Transformation import Transformation
 
 class Group(Actor):
 	def __init__(self):
+		Actor.__init__(self)
+
 		self._actors = []
 		self._layout = None
-		self._transf = Transformation()
 
 	def set_position(self, x, y):
 		Actor.set_position(self, x, y)
 		self._transf.set_translation(x, y)
 
 	def add(self, actor):
+		actor._parent = self
 		self._actors.append(actor)
 		self.do_layout()
 
@@ -33,7 +34,6 @@ class Group(Actor):
 		if self._layout:
 			self._layout.layout_group(self)
 
-	def render(self, drawable, transf):
-		transf = transf.compose(self._transf)
+	def render(self, drawable):
 		for actor in self._actors:
-			actor.render(drawable, transf)
+			actor.render(drawable)

sugar/scene/PixbufActor.py

@@ -8,7 +8,7 @@ class PixbufActor(Actor):
 
 		self._pixbuf = pixbuf
 
-	def render(self, drawable, transf):
-		(x, y) = transf.get_position(self._x, self._y)
+	def render(self, drawable):
+		(x, y) = self._get_abs_position(self._x, self._y)
 		gc = gtk.gdk.GC(drawable)
 		drawable.draw_pixbuf(gc, self._pixbuf, 0, 0, x, y)

sugar/scene/Stage.py

@@ -1,5 +1,4 @@
 from sugar.scene.Group import Group
-from sugar.scene.Transformation import Transformation
 
 class Stage(Group):
 	def __init__(self):
@@ -9,7 +8,5 @@ class Stage(Group):
 	def get_fps(self):
 		return self._fps
 
-	def render(self, drawable, transf = None):
-		if transf == None:
-			transf = Transformation()
-		Group.render(self, drawable, transf)
+	def render(self, drawable):
+		Group.render(self, drawable)