Remove buddies when they disappear. The canvas model / data model

separation makes this more complicated than I'd like. Maybe
it's worth to merge the two levels, I dunno.

shell/home/FriendsModel.py

@@ -17,7 +17,8 @@ class Friend:
 			icolor = IconColor(color)
 		except RuntimeError:
 			icolor = IconColor()
-			logging.info("Buddy %s doesn't have an allowed color; using a random color instead." % self.get_name())
+			logging.info("Buddy %s doesn't have an allowed color; \
+						  using a random color instead." % self.get_name())
 		return icolor
 
 class FriendsModel(gobject.GObject):
@@ -31,21 +32,29 @@ class FriendsModel(gobject.GObject):
 	def __init__(self):
 		gobject.GObject.__init__(self)
 		
-		self._friends = []
+		self._friends = {}
 		
 		self._pservice = PresenceService.get_instance()
 		self._pservice.connect("buddy-appeared", self.__buddy_appeared_cb)
+		self._pservice.connect("buddy-disappeared", self.__buddy_disappeared_cb)
 
 		for buddy in self._pservice.get_buddies():
 			self.add_friend(buddy)
 
 	def add_friend(self, buddy):
 		friend = Friend(buddy)
-		self._friends.append(friend)
+		self._friends[buddy.get_name()] = friend
 		self.emit('friend-added', friend)
 
+	def remove_friend(self, buddy):
+		self.emit('friend-removed', self._friends[buddy.get_name()])
+		del self._friends[buddy.get_name()]
+
 	def __iter__(self):
-		return self._friends.__iter__()
+		return self._friends.values().__iter__()
 
 	def __buddy_appeared_cb(self, pservice, buddy):
 		self.add_friend(buddy)
+
+	def __buddy_disappeared_cb(self, pservice, buddy):
+		self.remove_friend(buddy)

shell/home/FriendsView.py

@@ -3,38 +3,52 @@ import random
 import goocanvas
 
 from sugar.canvas.IconItem import IconItem
-
 import Theme
 
+class FriendIcon(IconItem):
+	def __init__(self, friend):
+		IconItem.__init__(self, 'stock-buddy', friend.get_color(), 48)
+
+		self._friend = friend
+
+		self.set_property('x', random.random() * 1100)
+		self.set_property('y', random.random() * 800)
+
+	def get_friend(self):
+		return self._friend
+
 class Model(goocanvas.CanvasModelSimple):
 	def __init__(self, data_model):
 		goocanvas.CanvasModelSimple.__init__(self)
+		self._friend_to_child = {}
+
 		self._theme = Theme.get_instance()
 		self._theme.connect("theme-changed", self.__theme_changed_cb)
 
-		root = self.get_root_item()
+		self._root = self.get_root_item()
 
 		color = self._theme.get_home_mesh_color()
 		self._mesh_rect = goocanvas.Rect(width=1200, height=900,
 										 fill_color=color)
-		root.add_child(self._mesh_rect)
+		self._root.add_child(self._mesh_rect)
 
 		color = self._theme.get_home_friends_color()
 		self._friends_rect = goocanvas.Rect(x=100, y=100, width=1000, height=700,
 											line_width=0, fill_color=color,
 											radius_x=30, radius_y=30)
-		root.add_child(self._friends_rect)
+		self._root.add_child(self._friends_rect)
 
 		color = self._theme.get_home_activities_color()
 		self._home_rect = goocanvas.Rect(x=400, y=300, width=400, height=300,
 										 line_width=0, fill_color=color,
 										 radius_x=30, radius_y=30)
-		root.add_child(self._home_rect)
+		self._root.add_child(self._home_rect)
 
 		for friend in data_model:
 			self.add_friend(friend)
 
 		data_model.connect('friend-added', self.__friend_added_cb)
+		data_model.connect('friend-removed', self.__friend_removed_cb)
 
 	def __theme_changed_cb(self, theme):
 		color = self._theme.get_home_activities_color()
@@ -45,16 +59,20 @@ class Model(goocanvas.CanvasModelSimple):
 		self._mesh_rect.set_property("fill-color", color)
 
 	def add_friend(self, friend):
-		root = self.get_root_item()
+		icon = FriendIcon(friend)
+		self._root.add_child(icon)
+		self._friend_to_child[friend] = icon
 
-		icon = IconItem('stock-buddy', friend.get_color(), 48)
+	def remove_friend(self, friend):
-		icon.set_property('x', random.random() * 1100)
+		icon = self._friend_to_child[friend]
-		icon.set_property('y', random.random() * 800)
+		self._root.remove_child(self._root.find_child(icon))
-
+		del self._friend_to_child[friend]
-		root.add_child(icon)
 
 	def __friend_added_cb(self, data_model, friend):
-		self.add_friend(friend)	
+		self.add_friend(friend)
+
+	def __friend_removed_cb(self, data_model, friend):
+		self.remove_friend(friend)
 
 class FriendsView(goocanvas.CanvasView):
 	def __init__(self, shell, data_model):