KiBot/kibot/svgutils/compose.py

418 lines
11 KiB
Python

# coding=utf-8
"""SVG definitions designed for easy SVG composing
Features:
* allow for wildcard import
* defines a mini language for SVG composing
* short but readable names
* easy nesting
* method chaining
* no boilerplate code (reading files, extracting objects from svg,
transversing XML tree)
* universal methods applicable to all element types
* don't have to learn python
"""
import os
import re
from . import transform
CONFIG = {
"svg.file_path": ".",
"figure.save_path": ".",
"image.file_path": ".",
"text.position": (0, 0),
"text.size": 8,
"text.weight": "normal",
"text.font": "Verdana",
}
class Element(transform.FigureElement):
"""Base class for new SVG elements."""
def rotate(self, angle, x=0, y=0):
"""Rotate element by given angle around given pivot.
Parameters
----------
angle : float
rotation angle in degrees
x, y : float
pivot coordinates in user coordinate system (defaults to top-left
corner of the figure)
"""
super(Element, self).rotate(angle, x, y)
return self
def move(self, x, y):
"""Move the element by x, y.
Parameters
----------
x,y : int, str
amount of horizontal and vertical shift
Notes
-----
The x, y can be given with a unit (for example, "3px", "5cm"). If no
unit is given the user unit is assumed ("px"). In SVG all units are
defined in relation to the user unit [1]_.
.. [1] W3C SVG specification:
https://www.w3.org/TR/SVG/coords.html#Units
"""
self.moveto(x, y)
return self
def find_id(self, element_id):
"""Find a single element with the given ID.
Parameters
----------
element_id : str
ID of the element to find
Returns
-------
found element
"""
element = transform.FigureElement.find_id(self, element_id)
return Element(element.root)
def find_ids(self, element_ids):
"""Find elements with given IDs.
Parameters
----------
element_ids : list of strings
list of IDs to find
Returns
-------
a new `Panel` object which contains all the found elements.
"""
elements = [transform.FigureElement.find_id(self, eid) for eid in element_ids]
return Panel(*elements)
class SVG(Element):
"""SVG from file.
Parameters
----------
fname : str
full path to the file
fix_mpl : bool
replace pt units with px units to fix files created with matplotlib
"""
def __init__(self, fname=None, fix_mpl=False):
if fname:
fname = os.path.join(CONFIG["svg.file_path"], fname)
svg = transform.fromfile(fname)
if fix_mpl:
w, h = svg.get_size()
svg.set_size((w.replace("pt", ""), h.replace("pt", "")))
super(SVG, self).__init__(svg.getroot().root)
# if height/width is in % units, we can't store the absolute values
if svg.width.endswith("%"):
self._width = None
else:
self._width = Unit(svg.width).to("px")
if svg.height.endswith("%"):
self._height = None
else:
self._height = Unit(svg.height).to("px")
@property
def width(self):
"""Get width of the svg file in px"""
if self._width:
return self._width.value
@property
def height(self):
"""Get height of the svg file in px"""
if self._height:
return self._height.value
class MplFigure(SVG):
"""Matplotlib figure
Parameters
----------
fig : matplotlib Figure instance
instance of Figure to be converted
kws :
keyword arguments passed to matplotlib's savefig method
"""
def __init__(self, fig, **kws):
svg = transform.from_mpl(fig, savefig_kw=kws)
self.root = svg.getroot().root
class Image(Element):
"""Raster or vector image
Parameters
----------
width : float
height : float
image dimensions
fname : str
full path to the file
"""
def __init__(self, width, height, fname):
fname = os.path.join(CONFIG["image.file_path"], fname)
_, fmt = os.path.splitext(fname)
fmt = fmt.lower()[1:]
with open(fname, "rb") as fid:
img = transform.ImageElement(fid, width, height, fmt)
self.root = img.root
class Text(Element):
"""Text element.
Parameters
----------
text : str
content
x, y : float or str
Text position. If unit is not given it will assume user units (px).
size : float, optional
Font size.
weight : str, optional
Font weight. It can be one of: normal, bold, bolder or lighter.
font : str, optional
Font family.
"""
def __init__(self, text, x=None, y=None, **kwargs):
params = {
"size": CONFIG["text.size"],
"weight": CONFIG["text.weight"],
"font": CONFIG["text.font"],
}
if x is None or y is None:
x, y = CONFIG["text.position"]
params.update(kwargs)
element = transform.TextElement(x, y, text, **params)
Element.__init__(self, element.root)
class Panel(Element):
"""Figure panel.
Panel is a group of elements that can be transformed together. Usually
it relates to a labeled figure panel.
Parameters
----------
svgelements : objects deriving from Element class
one or more elements that compose the panel
Notes
-----
The grouped elements need to be properly arranged in scale and position.
"""
def __init__(self, *svgelements):
element = transform.GroupElement(svgelements)
Element.__init__(self, element.root)
def __iter__(self):
elements = self.root.getchildren()
return (Element(el) for el in elements)
class Line(Element):
"""Line element connecting given points.
Parameters
----------
points : sequence of tuples
List of point x,y coordinates.
width : float, optional
Line width.
color : str, optional
Line color. Any of the HTML/CSS color definitions are allowed.
"""
def __init__(self, points, width=1, color="black"):
element = transform.LineElement(points, width=width, color=color)
Element.__init__(self, element.root)
class Grid(Element):
"""Line grid with coordinate labels to facilitate placement of new
elements.
Parameters
----------
dx : float
Spacing between the vertical lines.
dy : float
Spacing between horizontal lines.
size : float or str
Font size of the labels.
Notes
-----
This element is mainly useful for manual placement of the elements.
"""
def __init__(self, dx, dy, size=8):
self.size = size
lines = self._gen_grid(dx, dy)
element = transform.GroupElement(lines)
Element.__init__(self, element.root)
def _gen_grid(self, dx, dy, width=0.5):
xmax, ymax = 1000, 1000
x, y = 0, 0
lines = []
txt = []
while x < xmax:
lines.append(transform.LineElement([(x, 0), (x, ymax)], width=width))
txt.append(transform.TextElement(x, dy / 2, str(x), size=self.size))
x += dx
while y < ymax:
lines.append(transform.LineElement([(0, y), (xmax, y)], width=width))
txt.append(transform.TextElement(0, y, str(y), size=self.size))
y += dy
return lines + txt
class Figure(Panel):
"""Main figure class.
This should be always the top class of all the generated SVG figures.
Parameters
----------
width, height : float or str
Figure size. If unit is not given, user units (px) are assumed.
"""
def __init__(self, width, height, *svgelements):
Panel.__init__(self, *svgelements)
self.width = Unit(width)
self.height = Unit(height)
def save(self, fname):
"""Save figure to SVG file.
Parameters
----------
fname : str
Full path to file.
"""
element = transform.SVGFigure(self.width, self.height)
element.append(self)
element.save(os.path.join(CONFIG["figure.save_path"], fname))
def tostr(self):
"""Export SVG as a string"""
element = transform.SVGFigure(self.width, self.height)
element.append(self)
svgstr = element.to_str()
return svgstr
def _repr_svg_(self):
return self.tostr().decode("ascii")
def tile(self, ncols, nrows):
"""Automatically tile the panels of the figure.
This will re-arranged all elements of the figure (first in the
hierarchy) so that they will uniformly cover the figure area.
Parameters
----------
ncols, nrows : type
The number of columns and rows to arrange the elements into.
Notes
-----
ncols * nrows must be larger or equal to number of
elements, otherwise some elements will go outside the figure borders.
"""
dx = (self.width / ncols).to("px").value
dy = (self.height / nrows).to("px").value
ix, iy = 0, 0
for el in self:
el.move(dx * ix, dy * iy)
ix += 1
if ix >= ncols:
ix = 0
iy += 1
if iy > nrows:
break
return self
class Unit:
"""Implementation of SVG units and conversions between them.
Parameters
----------
measure : str
value with unit (for example, '2cm')
"""
per_inch = {"px": 90, "cm": 2.54, "mm": 25.4, "pt": 72.0}
def __init__(self, measure):
try:
self.value = float(measure)
self.unit = "px"
except ValueError:
m = re.match(r"([0-9]+\.?[0-9]*)([a-z]+)", measure)
value, unit = m.groups()
self.value = float(value)
self.unit = unit
def to(self, unit):
"""Convert to a given unit.
Parameters
----------
unit : str
Name of the unit to convert to.
Returns
-------
u : Unit
new Unit object with the requested unit and computed value.
"""
u = Unit("0cm")
u.value = self.value / self.per_inch[self.unit] * self.per_inch[unit]
u.unit = unit
return u
def __str__(self):
return "{}{}".format(self.value, self.unit)
def __repr__(self):
return "Unit({})".format(str(self))
def __mul__(self, number):
u = Unit("0cm")
u.value = self.value * number
u.unit = self.unit
return u
def __truediv__(self, number):
return self * (1.0 / number)
def __div__(self, number):
return self * (1.0 / number)