sugar-toolkit-gtk3/sugar/graphics/spreadbox.py
Marco Pesenti Gritti ebb896cb5b Another iteration on the spread out box. Make it work
well also for the mesh.
2006-10-25 14:31:44 +02:00

133 lines
3.3 KiB
Python

# Copyright (C) 2006, 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 random
import math
import cairo
import hippo
_DISTANCE_THRESHOLD = 10.0
_FORCE_CONSTANT = 0.1
class SpreadBox(hippo.CanvasBox, hippo.CanvasItem):
__gtype_name__ = 'SugarSpreadBox'
def __init__(self, **kwargs):
hippo.CanvasBox.__init__(self, **kwargs)
self._items_to_position = []
self._stable = False
def add_item(self, item):
self._items_to_position.append(item)
self.append(item, hippo.PACK_FIXED)
def remove_item(self, item):
if self._items_to_position.count(item) > 0:
self._items_to_position.remove(item)
self.remove(item)
def _get_item_radius(self, item):
[width, height] = item.get_request()
return math.sqrt(width ** 2 + height ** 2) / 2
def _get_item_center(self, item):
[width, height] = item.get_request()
[x, y] = self.get_position(item)
c_x = int(x + float(width) / 2.0)
c_y = int(y + float(height) / 2.0)
return [c_x, c_y]
def _get_repulsion(self, icon1, icon2):
[c1_x, c1_y] = self._get_item_center(icon1)
[c2_x, c2_y] = self._get_item_center(icon2)
a = c2_x - c1_x
b = c2_y - c1_y
r1 = self._get_item_radius(icon1)
r2 = self._get_item_radius(icon2)
distance = math.sqrt(a ** 2 + b ** 2) - r1 - r2
if distance < _DISTANCE_THRESHOLD:
f_x = int(math.ceil(-_FORCE_CONSTANT * float(a)))
f_y = int(math.ceil(-_FORCE_CONSTANT * float(b)))
else:
f_x = 0
f_y = 0
return [f_x, f_y]
def _clamp_position(self, icon, x, y):
x = max(0, x)
y = max(0, y)
[item_w, item_h] = icon.get_request()
[box_w, box_h] = self.get_allocation()
x = min(box_w - item_w, x)
y = min(box_h - item_h, y)
return [x, y]
def _spread_icons(self):
self._stable = True
for icon1 in self.get_children():
vx = 0
vy = 0
for icon2 in self.get_children():
if icon1 != icon2:
[f_x, f_y] = self._get_repulsion(icon1, icon2)
if f_x != 0 or f_y != 0:
self._stable = False
vx += f_x
vy += f_y
if vx != 0 or vy != 0:
[x, y] = self.get_position(icon1)
new_x = x + vx
new_y = y + vy
[new_x, new_y] = self._clamp_position(icon1, new_x, new_y)
self.move(icon1, new_x, new_y)
def do_allocate(self, width, height):
hippo.CanvasBox.do_allocate(self, width, height)
for item in self._items_to_position:
[item_w, item_h] = item.get_request()
x = int(random.random() * width - item_w)
y = int(random.random() * height - item_h)
[x, y] = self._clamp_position(item, x, y)
self.move(item, x, y)
self._items_to_position = []
tries = 20
self._spread_icons()
while not self._stable and tries > 0:
self._spread_icons()
tries -= 1