sugar-toolkit-gtk3/sugar/graphics/spreadlayout.py

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Python
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import random
import math
import cairo
class SpreadLayout:
DISTANCE_THRESHOLD = 120.0
def __init__(self):
pass
def _get_distance(self, icon1, icon2):
[icon1_x, icon1_y] = self._constraints[icon1]
[icon2_x, icon2_y] = self._constraints[icon2]
a = icon1_x - icon2_x
b = icon1_y - icon2_y
return math.sqrt(a * a + b * b)
def _get_repulsion(self, icon1, icon2):
[icon1_x, icon1_y] = self._constraints[icon1]
[icon2_x, icon2_y] = self._constraints[icon2]
f_x = icon1_x - icon2_x
f_y = icon1_y - icon2_y
return [f_x, f_y]
def _spread_icons(self):
self._stable = True
for icon1 in self._icons:
vx = 0
vy = 0
[x, y] = self._constraints[icon1]
for icon2 in self._icons:
if icon1 != icon2:
distance = self._get_distance(icon1, icon2)
if distance <= IconLayout.DISTANCE_THRESHOLD:
self._stable = False
[f_x, f_y] = self._get_repulsion(icon1, icon2)
vx += f_x
vy += f_y
new_x = x + vx
new_y = y + vy
new_x = max(self._x1, new_x)
new_y = max(self._y1, new_y)
[width, height] = icon1.get_size_request()
new_x = min(self._x2 - width, new_x)
new_y = min(self._y2 - height, new_y)
self._constraints[icon1] = [new_x, new_y]
matrix = cairo.Matrix(1, 0, 0, 1, 0, 0)
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matrix.translate(new_x - (width / 2), new_y - (height / 2))
icon1.set_transform(matrix)
def update(self):
tries = 10
self._spread_icons()
while not self._stable and tries > 0:
self._spread_icons()
tries -= 1
def layout(self, box):
[width, height] = box.get_allocation()
for item in box.get_children():
x = int(random.random() * width)
y = int(random.random() * height)
box.move(item, x, y)