Inkscape – making an extension (plug-in)

I’ve been making some extensions in Inkscape recently and learned some things.
So here’s the first in a series about making an extension to help creating files for the Ponoko laser cutting service.

What we want is to make it easy to set the line color and style for the various kinds of Laser lines ponoko supports.
E.g. cutting line is blue and 0.1mm in width. Heavy Vector lines are red.

Its fairly easy to do it all manually but then sometimes you forget to set the line width or to check that every single line is the right “color”.

So it would be useful to have a couple of tools to help:
Validate:
1. check that all paths have one of the legal colours and have the right stroke width.
2. check all are paths and no text etc – prompt if there is.

Working:
1. set the selected paths to be one of the legal colors (7 of them, 8 including comment)
2. toggle the line widths between the proper width and a larger width.
This tool is useful when you work on the larger sheets – the lines are so small that when zoomed out the entire drawing looks blank.

So we are going to make several posts showing how to get this done.