# A CSplit is a Clock-shaped split: the children are grouped in a circle.
# The numbering is a little different from a real clock: the 12 o'clock
# position is called 0, not 12. This is a little easier since Python
# usually counts from zero. (BTW, there needn't be exactly 12 children.)
from math import pi,sin,cos
from Split import Split
class CSplit(Split):
#
def getminsize(self, m, (width, height)):
# Since things look best if the children are spaced evenly
# along the circle (and often all children have the same
# size anyway) we compute the max child size and assume
# this is each child's size.
for child in self.children:
wi, he = child.getminsize(m, (0, 0))
width = max(width, wi)
height = max(height, he)
# In approximation, the diameter of the circle we need is
# (diameter of box) * (#children) / pi.
# We approximate pi by 3 (so we slightly overestimate
# our minimal size requirements -- not so bad).
# Because the boxes stick out of the circle we add the
# box size to each dimension.
# Because we really deal with ellipses, do everything
# separate in each dimension.
n = len(self.children)
return width + (width*n + 2)/3, height + (height*n + 2)/3
#
def getbounds(self):
return self.bounds
#
def setbounds(self, bounds):
self.bounds = bounds
# Place the children. This involves some math.
# Compute center positions for children as if they were
# ellipses with a diameter about 1/N times the
# circumference of the big ellipse.
# (There is some rounding involved to make it look
# reasonable for small and large N alike.)
# XXX One day Python will have automatic conversions...
n = len(self.children)
fn = float(n)
if n == 0: return
(left, top), (right, bottom) = bounds
width, height = right-left, bottom-top
child_width, child_height = width*3/(n+4), height*3/(n+4)
half_width, half_height = \
float(width-child_width)/2.0, \
float(height-child_height)/2.0
center_h, center_v = center = (left+right)/2, (top+bottom)/2
fch, fcv = float(center_h), float(center_v)
alpha = 2.0 * pi / fn
for i in range(n):
child = self.children[i]
fi = float(i)
fh, fv = \
fch + half_width*sin(fi*alpha), \
fcv - half_height*cos(fi*alpha)
left, top = \
int(fh) - child_width/2, \
int(fv) - child_height/2
right, bottom = \
left + child_width, \
top + child_height
child.setbounds(((left, top), (right, bottom)))
#
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