sugar-toolkit-gtk3/shell/view/home/snowflakelayout.py
2007-07-05 13:33:29 +02:00

105 lines
3.3 KiB
Python

# 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 gobject
import hippo
from sugar.graphics import units
_BASE_RADIUS = units.points_to_pixels(20)
_CHILDREN_FACTOR = 1
class SnowflakeLayout(gobject.GObject,hippo.CanvasLayout):
__gtype_name__ = 'SugarSnowflakeLayout'
def __init__(self):
gobject.GObject.__init__(self)
self._nflakes = 0
def add(self, child):
self._box.append(child)
box_child = self._box.find_box_child(child)
box_child.is_center = False
self._nflakes += 1
def add_center(self, child):
self._box.append(child)
box_child = self._box.find_box_child(child)
box_child.is_center = True
def do_set_box(self, box):
self._box = box
def do_get_height_request(self, for_width):
size = self._calculate_size()
return (size, size)
def do_get_width_request(self):
size = self._calculate_size()
return (size, size)
def do_allocate(self, x, y, width, height,
req_width, req_height, origin_changed):
r = self._get_radius()
index = 0
for child in self._box.get_layout_children():
cx = x + width / 2
cy = x + height / 2
min_width, child_width = child.get_width_request()
min_height, child_height = child.get_height_request(child_width)
if child.is_center:
child.allocate(x + (width - child_width) / 2,
y + (height - child_height) / 2,
child_width, child_height, origin_changed)
else:
angle = 2 * math.pi * index / self._nflakes
dx = math.cos(angle) * r
dy = math.sin(angle) * r
child_x = int(x + (width - child_width) / 2 + dx)
child_y = int(y + (height - child_height) / 2 + dy)
child.allocate(child_x, child_y, child_width,
child_height, origin_changed)
index += 1
def _get_radius(self):
return int(_BASE_RADIUS + _CHILDREN_FACTOR * self._nflakes)
def _calculate_size(self):
size = 0
for child in self._box.get_layout_children():
[min_width, child_width] = child.get_width_request()
[min_height, child_height] = child.get_height_request(child_width)
new_size = max(child_width, child_height)
if not child.is_center:
new_size += self._get_radius() * 2
if new_size > size:
size = new_size
return size