Parasite, wake up!

Hi there!

In the last weeks I’ve been working on GTK+ themes, customizing some apps, and I missed the tools we have on the web world that allow us to to some live editing on CSS.

I remembered we had Parasite, a tool similar to Firebug, but for GTK+ apps. Unfortunately it didn’t support CSS tweaking. But it does now! I’ve made some improvements on it mainly to allow live editing of CSS, but not limited to that.

Some changes so far:

  • Live editing of CSS, for the whole application, or only for the selected widget
  • Ability to add/remove a CSS class for a specific widget. (Editing of pseudo-classes like :hover is planned)
  • In the Property inspector, if a property itself is another Object, we can also inspect it. (For example, you can inspect a Buffer inside a TextView)
  • A bit of UI change

I have made a small video showing the improvements:

Link to the video

The code is on the usual place, github:

Please, test it and file bugs/wishes/pull requests. /me is now wearing the maintainer hat 🙂

Note: it requires GTK+ 3.10 (and optionally python+gobject introspection for the python shell)


#1 Debarshi Ray on 12.18.13 at 07:11 PM

Cool. But the “usual” place has been for a while. During the period of August 2009 and November 2012 when there was a lull in the github repo, lots of people started keeping their own forks all over the place, which is why it was decided to consolidate everything into one place on

#2 Jonh Wendell on 12.18.13 at 07:57 PM

Hi Debarshi, good to know! I was even going to migrate it to gnome servers 🙂

So, ideally we should merge changes, what do you think? Is it being maintained on the gnome side?

#3 Nacho on 12.19.13 at 08:44 AM

Awesome work.

#4 Jakub Steiner on 12.19.13 at 09:22 AM

Excellent! Thank you so much.

#5 Alexander Larsson on 12.19.13 at 09:49 AM

It would be nice if there also was an easy way to switch themes so the custom CSS can be verified against multiple themes.

#6 Andreas Nilsson on 12.19.13 at 11:46 AM


#7 fabiand on 12.20.13 at 09:33 AM

Amazing work!

#8 Fitoschido on 12.22.13 at 10:20 AM

Hey! I thougth Parasite had finally succumbed to antiparasitics and died, but it’s nice to see him living 🙂

Thank you very much for your work!

#9 bijan on 12.27.13 at 02:49 AM

very nice