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# Copyright (C) 2006-2007 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.
import math
import cairo
import hippo
from sugar.graphics import units
_BASE_RADIUS = units.points_to_pixels(20)
_CHILDREN_FACTOR = 1
_FLAKE_DISTANCE = units.points_to_pixels(4)
class SnowflakeBox(hippo.CanvasBox, hippo.CanvasItem):
__gtype_name__ = 'SugarSnowflakeBox'
def __init__(self, **kwargs):
hippo.CanvasBox.__init__(self, **kwargs)
self._root = None
def set_root(self, icon):
self._root = icon
def _get_center(self):
[width, height] = self.get_allocation()
return [width / 2, height / 2]
def _get_radius(self):
return _BASE_RADIUS + _CHILDREN_FACTOR * self._get_n_children()
def _layout_root(self):
[width, height] = self._root.get_allocation()
[cx, cy] = self._get_center()
x = cx - (width / 2)
y = cy - (height / 2)
self.set_position(self._root, int(x), int(y))
def _get_n_children(self):
return len(self.get_children()) - 1
def _layout_child(self, child, index):
r = self._get_radius()
if (self._get_n_children() > 10):
r += _FLAKE_DISTANCE * (index % 3)
angle = 2 * math.pi * index / self._get_n_children()
[width, height] = child.get_allocation()
[cx, cy] = self._get_center()
x = cx + math.cos(angle) * r - (width / 2)
y = cy + math.sin(angle) * r - (height / 2)
self.set_position(child, int(x), int(y))
def _calculate_size(self):
max_child_size = 0
for child in self.get_children():
[min_w, natural_w] = child.get_width_request()
[min_h, natural_h] = child.get_height_request(min_w)
max_child_size = max (max_child_size, min_w)
max_child_size = max (max_child_size, min_h)
return self._get_radius() * 2 + max_child_size + _FLAKE_DISTANCE * 2
def do_get_height_request(self, for_width):
hippo.CanvasBox.do_get_height_request(self, for_width)
size = self._calculate_size()
return (size, size)
def do_get_width_request(self):
hippo.CanvasBox.do_get_width_request(self)
size = self._calculate_size()
return (size, size)
def do_allocate(self, width, height, origin_changed):
hippo.CanvasBox.do_allocate(self, width, height, origin_changed)
self._layout_root()
index = 0
for child in self.get_children():
if child != self._root:
self._layout_child(child, index)
index += 1
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