blob: 3f22e6c6a3e4d24636e710f1920ebf04a822b159 [file] [log] [blame]
import re
def _prefer_non_zero(*args):
for arg in args:
if arg != 0:
return arg
return 0.0
def _ntos(n):
# %f likes to add unnecessary 0's, %g isn't consistent about # decimals
return ("%.3f" % n).rstrip("0").rstrip(".")
def _strip_xml_ns(tag):
# ElementTree API doesn't provide a way to ignore XML namespaces in tags
# so we here strip them ourselves: cf. https://bugs.python.org/issue18304
return tag.split("}", 1)[1] if "}" in tag else tag
def _transform(raw_value):
# TODO assumes a 'matrix' transform.
# No other transform functions are supported at the moment.
# https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/transform
# start simple: if you aren't exactly matrix(...) then no love
match = re.match(r"matrix\((.*)\)", raw_value)
if not match:
raise NotImplementedError
matrix = tuple(float(p) for p in re.split(r"\s+|,", match.group(1)))
if len(matrix) != 6:
raise ValueError("wrong # of terms in %s" % raw_value)
return matrix
class PathBuilder(object):
def __init__(self):
self.paths = []
self.transforms = []
def _start_path(self, initial_path=""):
self.paths.append(initial_path)
self.transforms.append(None)
def _end_path(self):
self._add("z")
def _add(self, path_snippet):
path = self.paths[-1]
if path:
path += " " + path_snippet
else:
path = path_snippet
self.paths[-1] = path
def _move(self, c, x, y):
self._add("%s%s,%s" % (c, _ntos(x), _ntos(y)))
def M(self, x, y):
self._move("M", x, y)
def m(self, x, y):
self._move("m", x, y)
def _arc(self, c, rx, ry, x, y, large_arc):
self._add(
"%s%s,%s 0 %d 1 %s,%s"
% (c, _ntos(rx), _ntos(ry), large_arc, _ntos(x), _ntos(y))
)
def A(self, rx, ry, x, y, large_arc=0):
self._arc("A", rx, ry, x, y, large_arc)
def a(self, rx, ry, x, y, large_arc=0):
self._arc("a", rx, ry, x, y, large_arc)
def _vhline(self, c, x):
self._add("%s%s" % (c, _ntos(x)))
def H(self, x):
self._vhline("H", x)
def h(self, x):
self._vhline("h", x)
def V(self, y):
self._vhline("V", y)
def v(self, y):
self._vhline("v", y)
def _line(self, c, x, y):
self._add("%s%s,%s" % (c, _ntos(x), _ntos(y)))
def L(self, x, y):
self._line("L", x, y)
def l(self, x, y):
self._line("l", x, y)
def _parse_line(self, line):
x1 = float(line.attrib.get("x1", 0))
y1 = float(line.attrib.get("y1", 0))
x2 = float(line.attrib.get("x2", 0))
y2 = float(line.attrib.get("y2", 0))
self._start_path()
self.M(x1, y1)
self.L(x2, y2)
def _parse_rect(self, rect):
x = float(rect.attrib.get("x", 0))
y = float(rect.attrib.get("y", 0))
w = float(rect.attrib.get("width"))
h = float(rect.attrib.get("height"))
rx = float(rect.attrib.get("rx", 0))
ry = float(rect.attrib.get("ry", 0))
rx = _prefer_non_zero(rx, ry)
ry = _prefer_non_zero(ry, rx)
# TODO there are more rules for adjusting rx, ry
self._start_path()
self.M(x + rx, y)
self.H(x + w - rx)
if rx > 0:
self.A(rx, ry, x + w, y + ry)
self.V(y + h - ry)
if rx > 0:
self.A(rx, ry, x + w - rx, y + h)
self.H(x + rx)
if rx > 0:
self.A(rx, ry, x, y + h - ry)
self.V(y + ry)
if rx > 0:
self.A(rx, ry, x + rx, y)
self._end_path()
def _parse_path(self, path):
if "d" in path.attrib:
self._start_path(initial_path=path.attrib["d"])
def _parse_polygon(self, poly):
if "points" in poly.attrib:
self._start_path("M" + poly.attrib["points"])
self._end_path()
def _parse_polyline(self, poly):
if "points" in poly.attrib:
self._start_path("M" + poly.attrib["points"])
def _parse_circle(self, circle):
cx = float(circle.attrib.get("cx", 0))
cy = float(circle.attrib.get("cy", 0))
r = float(circle.attrib.get("r"))
# arc doesn't seem to like being a complete shape, draw two halves
self._start_path()
self.M(cx - r, cy)
self.A(r, r, cx + r, cy, large_arc=1)
self.A(r, r, cx - r, cy, large_arc=1)
def _parse_ellipse(self, ellipse):
cx = float(ellipse.attrib.get("cx", 0))
cy = float(ellipse.attrib.get("cy", 0))
rx = float(ellipse.attrib.get("rx"))
ry = float(ellipse.attrib.get("ry"))
# arc doesn't seem to like being a complete shape, draw two halves
self._start_path()
self.M(cx - rx, cy)
self.A(rx, ry, cx + rx, cy, large_arc=1)
self.A(rx, ry, cx - rx, cy, large_arc=1)
def add_path_from_element(self, el):
tag = _strip_xml_ns(el.tag)
parse_fn = getattr(self, "_parse_%s" % tag.lower(), None)
if not callable(parse_fn):
return False
parse_fn(el)
if "transform" in el.attrib:
self.transforms[-1] = _transform(el.attrib["transform"])
return True