Implement close button for the activity.

Some fixes.

shell/view/frame/RightPanel.py

@@ -70,8 +70,11 @@ class RightPanel(CanvasBox):
 							'buddy-left', self.__buddy_left_cb)
 
 	def __activity_changed_cb(self, group, activity):
-		activity_ps = self._pservice.get_activity(activity.get_id())
-		self._set_activity_ps(activity_ps)				
+		if activity:
+			ps = self._pservice.get_activity(activity.get_id())
+			self._set_activity_ps(ps)
+		else:
+			self._set_activity_ps(None)
 
 	def __buddy_joined_cb(self, activity, buddy):
 		self.add(buddy)

shell/view/frame/TopPanel.py

@@ -9,6 +9,7 @@ import sugar
 
 class ActivityMenu(Menu):
 	ACTION_SHARE = 1
+	ACTION_CLOSE = 2
 
 	def __init__(self, grid, activity_host):
 		title = activity_host.get_title()
@@ -17,6 +18,9 @@ class ActivityMenu(Menu):
 		icon = IconItem(icon_name='stock-share')
 		self.add_action(icon, ActivityMenu.ACTION_SHARE) 
 
+		icon = IconItem(icon_name='stock-close-activity')
+		self.add_action(icon, ActivityMenu.ACTION_CLOSE) 
+
 class ActivityIcon(MenuIcon):
 	def __init__(self, shell, activity_host):
 		self._shell = shell
@@ -36,10 +40,16 @@ class ActivityIcon(MenuIcon):
 		return menu
 
 	def _action_cb(self, menu, action):
+		self.popdown()
+
+		activity = self._shell.get_current_activity()
+		if activity == None:
+			return
+
 		if action == ActivityMenu.ACTION_SHARE:
-			activity = shell.get_current_activity()
-			if activity != None:
-				activity.share()
+			activity.share()
+		if action == ActivityMenu.ACTION_CLOSE:
+			activity.close()
 
 class TopPanel(goocanvas.Group):
 	def __init__(self, shell):