Hello everyone,

I’m trying to develop an extension for Inkscape that creates responsive grids, similar to what can be done in FIGMA. I’m not a developer—just a designer looking to create a feature that could be useful for other designers. So far, I’ve used ChatGPT to achieve the current results. The extension works, but it needs a few adjustments:

1. Whenever I change a parameter with the preview enabled, a dialog box pops up, requiring me to confirm the action to update the preview. This is quite inconvenient.
2. For some reason, if I choose any page format other than A4, making changes to the parameters (with the preview enabled) reverts my page back to the A4 format.
3. I’d like to add a parameter to allow users to choose the grid’s color and opacity.

No matter how hard I try, I can’t seem to solve these issues. Could someone please help me?

#!/usr/bin/env python3

# coding=utf-8

"""
Inkscape's responsive grid extension. Creates a grid of red rectangles
with specified columns, column width, and gutter, adjusted to the active page size.
"""

import inkex
from lxml import etree


class ResponsiveGrid(inkex.GenerateExtension):
    """
    Responsive Grid extension for Inkscape
    """

    def add_arguments(self, pars):
        pars.add_argument("--columns", type=int, default=12, help="Number of columns")
        pars.add_argument("--column_width", type=float, default=50, help="Width of each column (px)")
        pars.add_argument("--gutter", type=float, default=20, help="Gutter width (px)")

    def generate(self):
        # Get dimensions of the active page
        svg_root = self.document.getroot()
        canvas_width = float(svg_root.get("width", "0").replace("mm", "").replace("px", ""))
        canvas_height = float(svg_root.get("height", "0").replace("mm", "").replace("px", ""))

        # Get user parameters
        columns = self.options.columns
        column_width = self.options.column_width
        gutter = self.options.gutter

        # Validate parameters
        if columns < 1 or column_width <= 0 or gutter < 0:
            return  # Exit without generating anything if parameters are invalid

        # Calculate total width occupied by columns and gutters
        total_width = (column_width * columns) + (gutter * (columns - 1))
        margin = (canvas_width - total_width) / 2

        # Register namespaces explicitly
        namespaces = {**svg_root.nsmap, 'inkscape': inkex.NSS['inkscape']}

        # Remove existing grid group (if any)
        existing_grid = svg_root.find(".//svg:g[@inkscape:label='Responsive Grid']", namespaces)
        if existing_grid is not None:
            svg_root.remove(existing_grid)

        # Create a group for the columns
        grid_group = etree.Element(inkex.addNS("g", "svg"))
        grid_group.set(inkex.addNS("label", "inkscape"), "Responsive Grid")
        grid_group.set(inkex.addNS("groupmode", "inkscape"), "layer")
        grid_group.set(inkex.addNS("locked", "inkscape"), "true")

        # Draw the columns
        x = margin
        for _ in range(columns):
            column = etree.Element(inkex.addNS("rect", "svg"))
            column.set("x", str(x))
            column.set("y", "0")
            column.set("width", str(column_width))
            column.set("height", str(canvas_height))
            column.set("style", "fill:red;fill-opacity:0.1;stroke:none")
            grid_group.append(column)
            x += column_width + gutter

        # Add the group to the SVG document
        svg_root.append(grid_group)


if __name__ == "__main__":
    ResponsiveGrid().run()

<?xml version="1.0" encoding="UTF-8"?>
<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
  <!-- Extension name and ID -->
  <name>Responsive Grid Creator</name>
  <id>org.inkscape.render.responsive_grid</id>

  <!-- Extension parameters -->
  <param name="columns" type="int" gui-text="Number of Columns:" min="1" max="50" default="12" />
  <param name="column_width" type="float" gui-text="Column Width (px):" min="1" max="1000" default="50" />
  <param name="gutter" type="float" gui-text="Gutter Width (px):" min="0" max="500" default="20" />

  <!-- Menu and location -->
  <effect>
    <object-type>all</object-type>
    <effects-menu>
      <submenu name="Render">
        <submenu name="Responsive Grid" />
      </submenu>
    </effects-menu>
  </effect>

  <!-- Associated Python script -->
  <script>
    <command location="inx" interpreter="python">responsive_grid.py</command>
  </script>
</inkscape-extension>

You don't need to deal with namespaces, that's from a long time ago < Inkscape 1.0

Have a go with this, should work.

import inkex

from inkex import Layer, Rectangle


#Unit conversions
conversions = {
    'in': 96.0,
    'pt': 1.3333333333333333,
    'px': 1.0,
    'mm': 3.779527559055118,
    'cm': 37.79527559055118,
    'm': 3779.527559055118,
    'km': 3779527.559055118,
    'Q': 0.94488188976378,
    'pc': 16.0,
    'yd': 3456.0,
    'ft': 1152.0,
    '': 1.0,  # Default px
}

class ResponsiveGrid(inkex.EffectExtension):


    def add_arguments(self, pars):

        pars.add_argument("--columns", type=int, default=12, help="Number of columns")
        pars.add_argument("--column_width", type=float, default=50, help="Width of each column (px)")
        pars.add_argument("--gutter", type=float, default=20, help="Gutter width (px)")
    
    def effect(self):

        # Get dimensions of the active page
        # svg_root = self.document.getroot()
        svg_root = self.svg
        # Lets get the svg user units
        svg_units = self.svg.unit
        pixel_conversion_factor = conversions[svg_units]

        # canvas_width = float(svg_root.get("width", "0").replace("mm", "").replace("px", ""))
        # canvas_height = float(svg_root.get("height", "0").replace("mm", "").replace("px", ""))

        canvas_pixel_width = self.svg.viewbox_width * pixel_conversion_factor
        canvas_pixel_height = self.svg.viewbox_height * pixel_conversion_factor

        # Get user parameters
        columns = self.options.columns
        column_width = self.options.column_width
        gutter = self.options.gutter

        # Validate parameters
        if columns < 1 or column_width <= 0 or gutter < 0:
            return  # Exit without generating anything if parameters are invalid

        # Calculate total width occupied by columns and gutters
        total_width = (column_width * columns) + (gutter * (columns - 1))
        margin = (canvas_pixel_width - total_width) / 2

        # Register namespaces explicitly
        # namespaces = {**svg_root.nsmap, 'inkscape': inkex.NSS['inkscape']}

        # Remove existing grid group (if any)
        # existing_grid = svg_root.find(".//svg:g[@inkscape:label='Responsive Grid']", namespaces)

        # Get all existing grids as a list
        existing_grids = self.svg.xpath('//svg:g[@inkscape:label="Responsive Grid"]')

        if existing_grids is not None:
            for grid in existing_grids:
                svg_root.remove(grid)

        # Create a group for the columns
        # grid_group = etree.Element(inkex.addNS("g", "svg"))
        # grid_group.set(inkex.addNS("label", "inkscape"), "Responsive Grid")
        # grid_group.set(inkex.addNS("groupmode", "inkscape"), "layer")
        # grid_group.set(inkex.addNS("locked", "inkscape"), "true")

        #Create a new layer, lock using sodipodi insensitive
        grid_group = Layer()
        grid_group.set('inkscape:label', 'Responsive Grid')
        grid_group.set('sodipodi:insensitive', 'true')

        # Draw the columns
        x = margin
        for _ in range(columns):
            # column = etree.Element(inkex.addNS("rect", "svg"))
            column = Rectangle()
            column.set("x", str(x / pixel_conversion_factor))
            column.set("y", "0")
            column.set("width", str(column_width / pixel_conversion_factor))
            column.set("height", str(self.svg.viewbox_height))
            column.set("style", "fill:red;fill-opacity:0.1;stroke:none")
            grid_group.append(column)
            x += column_width + gutter

        # Add the group to the SVG document
        svg_root.append(grid_group)
        
if __name__ == '__main__':
    ResponsiveGrid().run()

Wow, it worked, and the confirmation window no longer appears! Thank you so much for your help!!! However, there’s still an issue that might be related to Inkscape itself and not the extension: if I start Inkscape and select the "iPhone 5" screen format, for example, when I run the extension and adjust the parameters with the preview enabled, my page changes to A4 format. Do you have any idea what might be causing this?

Yes I suspect you are directly altering the page size in error, possibly inserting invalid values or text? 

I would expect the A4 is a fallback when the svg has somehow been corrupted in the extension system.

I forgot to mention, I changed to an effect extension instead of the generator extension you are using. 

Apart from saving / opening almost all extensions are effect extensions. Generator extensions are a special case which isn't widely used.