Add a spread layout manager. Work in progress.

shell/view/home/snowflakelayout.py

@@ -28,7 +28,7 @@ _CHILDREN_FACTOR = 1
 class SnowflakeLayout(gobject.GObject,hippo.CanvasLayout):
     __gtype_name__ = 'SugarSnowflakeLayout'
     def __init__(self):
-        hippo.CanvasBox.__init__(self)
+        gobject.GObject.__init__(self)
         self._nflakes = 0
 
     def add(self, child):

sugar/graphics/spreadlayout.py

@@ -0,0 +1,131 @@
+# Copyright (C) 2007 Red Hat, Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+from array import array
+from random import random
+
+import hippo
+import gobject
+import gtk
+
+_PLACE_TRIALS = 20
+_MAX_WEIGHT = 255
+_CELL_SIZE = 4
+
+class _Grid(object):
+    def __init__(self, width, height):
+        self.width = width
+        self.height = height
+
+        self._array = array('B')
+        for i in range(width * height):
+            self._array.append(0)
+
+    def add(self, child, width, height):
+        trials = _PLACE_TRIALS
+        weight = _MAX_WEIGHT
+        while trials > 0 and weight:
+            x = int(random() * (self.width - width))
+            y = int(random() * (self.height - height))
+
+            rect = gtk.gdk.Rectangle(x, y, width, height)
+            new_weight = self._compute_weight(rect)
+            if weight > new_weight:
+                weight = new_weight
+
+            trials -= 1
+
+        child.grid_rect = rect
+        self._add_weight(rect)
+
+    def remove(self, child):
+        self._remove_weight(box_child.grid_rect)
+        child.grid_rect = None
+
+    def _add_weight(self, rect):
+        for i in range(rect.x, rect.x + rect.width):
+            for j in range(rect.y, rect.y + rect.height):
+                self[j, i] += 1
+
+    def _remove_weight(self, rect):
+        for i in range(rect.x, rect.x + rect.width):
+            for j in range(rect.y, rect.y + rect.height):
+                self[j, i] -= 1
+
+    def _compute_weight(self, rect):
+        weight = 0
+
+        for i in range(rect.x, rect.x + rect.width):
+            for j in range(rect.y, rect.y + rect.height):
+                weight += self[j, i]
+                
+        return weight
+    
+    def __getitem__(self, (row, col)):
+        return self._array[col + row * self.width]
+
+    def __setitem__(self, (row, col), value):
+        self._array[col + row * self.width] = value
+
+
+class SpreadLayout(gobject.GObject,hippo.CanvasLayout):
+    __gtype_name__ = 'SugarSpreadLayout'
+    def __init__(self):
+        gobject.GObject.__init__(self)
+
+        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)
+
+    def add(self, child):
+        self._box.append(child)
+
+        width, height = self._get_child_grid_size(child)
+        box_child = self._box.find_box_child(child)
+        self._grid.add(box_child, width, height)
+
+    def remove(self, child):
+        box_child = self._box.find_box_child(child)
+        self._grid.remove(box_child)
+
+        self._box.remove(child)
+
+    def do_set_box(self, box):
+        self._box = box
+
+    def do_get_height_request(self, for_width):
+        return 0, gtk.gdk.screen_height()
+
+    def do_get_width_request(self):
+        return 0, gtk.gdk.screen_width()
+
+    def do_allocate(self, x, y, width, height,
+                    req_width, req_height, origin_changed):
+        for child in self._box.get_layout_children():
+            rect = child.grid_rect
+            child.allocate(rect.x * _CELL_SIZE,
+                           rect.y * _CELL_SIZE,
+                           rect.width * _CELL_SIZE,
+                           rect.height * _CELL_SIZE,
+                           origin_changed)
+
+    def _get_child_grid_size(self, child):
+        min_width, width = child.get_width_request()
+        min_height, height = child.get_height_request(width)
+
+        return int(width / _CELL_SIZE), int(height / _CELL_SIZE)

tests/test-spread-box.py

@@ -26,7 +26,7 @@ import gobject
 import gtk
 import hippo
 
-from sugar.graphics.spreadbox import SpreadBox
+from sugar.graphics.spreadlayout import SpreadLayout
 from sugar.graphics.xocolor import XoColor
 from sugar.graphics.canvasicon import CanvasIcon
 
@@ -35,7 +35,7 @@ def _create_icon():
 
     icon = CanvasIcon(scale=1.0, xo_color=color,
                       icon_name='theme:stock-buddy')
-    box.add_item(icon)
+    layout.add(icon)
 
     return (len(box.get_children()) < 20)
 
@@ -45,7 +45,11 @@ window.show()
 
 canvas = hippo.Canvas()
 
-box = SpreadBox(background_color=0xe2e2e2ff)
+box = hippo.CanvasBox(background_color=0xe2e2e2ff)
+
+layout = SpreadLayout()
+box.set_layout(layout)
+
 canvas.set_root(box)
 
 window.add(canvas)