Rewrite of the grid stuff. Simpler api and cleaner implementation.

Also follow the micro grids in pentagram design.

tests/test-grid.py

@@ -13,9 +13,8 @@ import goocanvas
 from sugar.canvas.IconColor import IconColor
 from sugar.canvas.IconItem import IconItem
 from sugar.canvas.CanvasView import CanvasView
-from sugar.canvas.GridBox import GridBox
-from sugar.canvas.GridModel import GridModel
-from sugar.canvas.GridLayout import GridConstraints
+from sugar.canvas.CanvasBox import CanvasBox
+from sugar.canvas.Grid import Grid
 
 def _new_icon_clicked_cb(icon):
 	box.remove_child(icon)
@@ -25,21 +24,26 @@ def _icon_clicked_cb(icon):
 	icon.connect('clicked', _new_icon_clicked_cb)
 	box.add_child(icon, 0)
 
-model = GridModel('#4f4f4f')
-layout = model.get_layout()
+model = goocanvas.CanvasModelSimple()
+root = model.get_root_item()
 
-box = GridBox(GridBox.HORIZONTAL, 5, 6)
-layout.set_constraints(box, GridConstraints(0, 0, 5, 1))
-model.add(box)
+grid = Grid()
+
+box = CanvasBox(grid, CanvasBox.HORIZONTAL, 1)
+grid.set_constraints(box, 5, 5)
+root.add_child(box)
 
 rect = goocanvas.Rect(fill_color='red')
+box.set_constraints(rect, 5, 5)
 box.add_child(rect)
 
 icon = IconItem(color=IconColor(), icon_name='activity-web')
 icon.connect('clicked', _icon_clicked_cb)
+box.set_constraints(icon, 5, 5)
 box.add_child(icon)
 
 icon = IconItem(color=IconColor(), icon_name='activity-groupchat')
+box.set_constraints(icon, 5, 5)
 box.add_child(icon)
 
 window = gtk.Window()
@@ -49,6 +53,6 @@ window.show()
 canvas = CanvasView()
 canvas.show()
 window.add(canvas)
-canvas.set_model(model.get())
+canvas.set_model(model)
 
 gtk.main()