Inkscape Extension - Part One

   
   
 inkscape  python  
 design  
Related Articles

Inkscape Automation for Productivity.

Where to Discuss?

Local Group

Table of Content

Preface

Introduction to inkscape extension.

Inkscape is a powerful design tool, one of them is the inkscape extension. Inkscape extension bring python programming to design.

I can automate repetitive task using python, saving a lot of working hour. Manual task is also error prone, inkscape automation reduce human error.

However, there is somewhere where you should start with.

Getting Started

Reading

I’m not sure where the landing page is, but I find this link is useful.

Official Example

The Offical Example is, of course the inkscape itself.

Inkscape Extension - Menu

Now, where is the extension directory?

There are two kind of directory

  • System Directory

  • User Directory

Note that Windows and Linux has different path.

System Directory

Here lies the directories where you can find good examples.

  • Linux: /usr/share/inkscape/extensions

  • Windows: C:\\Program Files\Inkscape\share\inkscape\extensions

Inkscape Extension - System Directory

I suggest that you start with colors. They are short, thus easy to learn with.

User Directory

Now it is time for you to start your own extension. So prepare your directory.

  • Linux: ~/.config/inkscape/extensions

  • Windows: C:\\Users\[username]\AppData\Roaming\Inkscape\extensions

A Pair of Files

As you can see above, to make an extension you need two pair of file.

  • The inx file: contain an XML file for menu setting.

  • The py file: contain the python code

XML Parameters

You can read the details of the XML parameters here:

Generate Extension

Consider begin with something easy, the generating hello world.

Artefacts

We need two files.

  • hello.inx
  • hello.py

Put these two files below on your user directoy. In order to have the menu activated, you should restart your inkscape.

Hello World - Menu

Hello World XML

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension
  xmlns="http://www.inkscape.org/namespace/inkscape/extension">
  <name>Test Hello</name>
  <id>epsi.hello</id>
  <param name="greeting_text" type="string"
         gui-text="Greeting Text:">Hello World</param>
  <effect>
    <object-type>all</object-type>
    <effects-menu>
       <submenu name="Epsi"/>
    </effects-menu>
  </effect>
  <script>
    <command location="inx" interpreter="python">hello.py</command>
  </script>
</inkscape-extension>

Hello World

Start with importing inkex

#!/usr/bin/env python
import inkex
from inkex.elements import TextElement

class Hello(inkex.GenerateExtension):
    def add_arguments(self, pars):
        pars.add_argument("--greeting_text",
            type=str, default="Yellow Here",
            help="Cute Greeting Text")

    def generate(self):
      textElement = TextElement()
      textElement.text = str(self.options.greeting_text)
      return textElement

if __name__ == '__main__':
    Hello().run()

What Does It Do?

This simply ask for a greet parameter, then create a text element.

Hello Extension - Preview

Effect Extension

Instead of generate something new, inkscape extension can read any object, and alter the properties.

Or you can also generate any shape, on a selected layer.

Official Tutorial

Consider begin with something official form inkscape.

The official tutorial is here:

I change a little bit to suit my needs.

Artefacts

We need two files.

  • rectangle.inx
  • rectangle.py

Rectangle - Menu

Rectangle XML

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension
  xmlns="http://www.inkscape.org/namespace/inkscape/extension">
  <name>Test Rectangle</name>
  <id>epsi.rectangle</id>
  <effect>
    <object-type>all</object-type>
    <effects-menu>
       <submenu name="Epsi"/>
    </effects-menu>
  </effect>
  <script>
    <command location="inx"
             interpreter="python">rectangle.py</command>
  </script>
</inkscape-extension>

Rectangle Python

The structure of the extension is shown as below.

#!/usr/bin/env python

import inkex, simplestyle
from lxml import etree

def draw_SVG_square(w,h, x,y, parent):
    ...

class Kotak(inkex.EffectExtension):
  def effect(self):
    parent = self.svg.get_current_layer()
    draw_SVG_square(100,100, 0,0, parent)

if __name__ == '__main__':
  Kotak().run()

While the draw_SVG_square function is as below:

def draw_SVG_square(w,h, x,y, parent):
    style = { 'stroke'        : 'none',
              'stroke-width'  : '1',
              'fill'          : '#000000'
            }

    attribs = {
        'style'     : str(inkex.Style(style)),
        'height'    : str(h),
        'width'     : str(w),
        'x'         : str(x),
        'y'         : str(y)
            }
    circ = etree.SubElement(
        parent, inkex.addNS('rect','svg'), attribs )
    return circ

Notice the inkex namespace and inkex style.

What Does It Do?

This simply ask for a greet parameter, then create a text element.

Rectangle Extension - Result

XML Editor

As you can see above, the draw_SVG_square functions looks like a CSS.

In fact it is an XML properties.

Rectangle Shape - XML Editor

We are going to deal a lot with XML stuff later.

What is Next ?

Consider continue reading [ Inkscape Automation - Part Two ].

Thank you for reading.