Cleanup center item offset API

shell/view/home/MeshBox.py

@@ -382,8 +382,7 @@ class MeshBox(hippo.CanvasBox):
         self._layout_box = hippo.CanvasBox(background_color=0xe2e2e2ff)
         self.append(self._layout_box, hippo.PACK_EXPAND)
 
-        center_vertical_offset = - style.GRID_CELL_SIZE
-        self._layout = SpreadLayout(center_vertical_offset)
+        self._layout = SpreadLayout()
         self._layout_box.set_layout(self._layout)
 
         for buddy_model in self._model.get_buddies():
@@ -466,7 +465,8 @@ class MeshBox(hippo.CanvasBox):
     def _add_alone_buddy(self, buddy_model):
         icon = BuddyIcon(self._shell, buddy_model)
         if buddy_model.is_owner():
-            self._layout.add_center(icon)
+            vertical_offset = - style.GRID_CELL_SIZE
+            self._layout.add_center(icon, vertical_offset)
         else:
             self._layout.add(icon)
 

shell/view/home/spreadlayout.py

@@ -169,18 +169,16 @@ class _Grid(gobject.GObject):
 
 class SpreadLayout(gobject.GObject, hippo.CanvasLayout):
     __gtype_name__ = 'SugarSpreadLayout'
-    def __init__(self, center_vertical_offset=0):
+    def __init__(self):
         gobject.GObject.__init__(self)
 
-        self._center_vertical_offset = center_vertical_offset
-
         min_width, width = self.do_get_width_request()
         min_height, height = self.do_get_height_request(width)
 
         self._grid = _Grid(width / _CELL_SIZE, height / _CELL_SIZE)
         self._grid.connect('child-changed', self._grid_child_changed_cb)
 
-    def add_center(self, child):
+    def add_center(self, child, vertical_offset=0):
         self._box.append(child)
 
         width, height = self._get_child_grid_size(child)
@@ -191,6 +189,7 @@ class SpreadLayout(gobject.GObject, hippo.CanvasLayout):
 
         box_child = self._box.find_box_child(child)
         box_child.grid_rect = None
+        box_child.vertical_offset = vertical_offset
 
     def add(self, child):
         self._box.append(child)
@@ -225,10 +224,11 @@ class SpreadLayout(gobject.GObject, hippo.CanvasLayout):
                                rect.height * _CELL_SIZE,
                                origin_changed)
             else:
+                vertical_offset = child.vertical_offset
                 min_w, child_width = child.get_width_request()
                 min_h, child_height = child.get_height_request(child_width)
                 child_x = x + (width - child_width) / 2
-                child_y = y + (height - child_height + self._center_vertical_offset) / 2
+                child_y = y + (height - child_height + vertical_offset) / 2
                 child.allocate(child_x, child_y, child_width, child_height,
                                origin_changed)