def update_positions(self, renderer):
x, y = self.xytext
self._x, self._y = self._get_xy(x, y, self.textcoords)
x, y = self.xy
x, y = self._get_xy(x, y, self.xycoords)
if self.arrowprops:
x0, y0 = x, y
l, b, w, h = self.get_window_extent(renderer).get_bounds()
dpi = self.figure.dpi.get()
r = l + w
t = b + h
xc = 0.5 * (l + r)
yc = 0.5 * (b + t)
# pick the x,y corner of the text bbox closest to point
# annotated
dsu = [(abs(val - x0), val) for val in l, r, xc]
dsu.sort()
d, x = dsu[0]
dsu = [(abs(val - y0), val) for val in b, t, yc]
dsu.sort()
d, y = dsu[0]
d = self.arrowprops.copy()
width = d.pop('width', 4)
headwidth = d.pop('headwidth', 12)
frac = d.pop('frac', 0.1)
shrink = d.pop('shrink', 0.0)
theta = math.atan2(y - y0, x - x0)
r = math.sqrt((y - y0)**2. + (x - x0)**2.)
dx = shrink * r * math.cos(theta)
dy = shrink * r * math.sin(theta)
self.arrow = YAArrow(self.figure.dpi, (x0 + dx, y0 + dy),
(x - dx, y - dy),
width=width,
headwidth=headwidth,
frac=frac,
**d)
self.arrow.set_clip_box(self.get_clip_box())
