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I've written a script in Python in order to automatically scrape data from graphs saved in svg.
I need to get the center positions of the objects selected in Inkscape. I looked for a convenient way to do it, and the only solution I found was to call externally the Inkscape command this way:
inkscape --query-id=node_id -X temporary_svg_path
It has the major drawback of being extremely slow when many points are selected. Is there an easy way to do so ?
Thanks
Raphaël
Find the center of an object in a script
-
samueldellicour
- Posts: 26
- Joined: Mon Jul 01, 2013 11:03 pm
- Location: Belgium
- Contact:
Re: Find the center of an object in a script
In my extension to add guides through the center of a SINGLE selected object, I use the following code. Maybe you can use that as a start?
With some imports at the beginning of the file:
I'm not a programmer, and have used various sources to build the code, so I cannot explain every single line of the code I used, but it works for me
Code: Select all
# getting the main SVG document element (canvas)
svg = self.document.getroot()
# getting the width and height attributes of the canvas
canvas_width = self.unittouu(svg.get('width'))
canvas_height = self.unittouu(svg.attrib['height'])
# check if a selection exists
if not self.options.ids:
inkex.errormsg(_("No objects selected. Please select an object first."))
exit()
# query bounding box, UPPER LEFT corner (?)
q = {'x':0, 'y':0, 'width':0, 'height':0}
for query in q.keys():
p = Popen(
'inkscape --query-%s --query-id=%s "%s"' % (query, self.options.ids[0], self.args[-1], ),
shell=True,
stdout=PIPE,
stderr=PIPE,
)
p.wait()
q[query] = p.stdout.read()
# get width, height, center of bounding box
obj_width = float(q['width'])
obj_height = float(q['height'])
center_x = float(q['x']) + obj_width/2
center_y = ( canvas_height - float(q['y']) - obj_height ) + obj_height/2
With some imports at the beginning of the file:
Code: Select all
import inkex
import gettext
_ = gettext.gettext
from subprocess import Popen, PIPE
I'm not a programmer, and have used various sources to build the code, so I cannot explain every single line of the code I used, but it works for me
Samuel