Universal Applets Update

I’m reposting a shortened version of this email to the Gnome-love list. The bolded bit talks about the project’s current status.

I’m trying to fix the problem by creating a universal applets framework for GNOME that’s mostly based on Screenlets. The goal is to create a common applet format that can be easily loaded into any gtk (and even qt) application without forcing the applet developer to give up on specialized applet functionality.

The framework consists of two main parts- Screenlets and ScreenletContainers. Both are written in Python, but can easily be reimplemented in C or in any other language.

Screenlets contain a gtk.Layout. They can pack widgets into the gtk.Layout, draw on it, or do both. Screenlets support theming, editable options (options which save real time and can be edited with a gui), and DBUS services without any extra work on the developers part. They are completely scalable.

ScreenletContainers are responsible for loading and displaying Screenlets. The ScreenletContainer base class implements most of the functions necessary for loading and showing a Screenlet in a generic location. Any application can import the ScreenletContainer class and use it directly (or subclass it) to add on support for Screenlets.

There is a ToplevelContainer class which descends from ScreenletContainer and is responsible for embedding Screenlets in a toplevel window. ToplevelContainer adds on a few extra options for displaying Screenlets. (E.g. “keep above other windows”, “show on all desktops”, “show as a compiz fusion widget”, and so on and so forth.)

Right now, screenlets interact with their containers using hacked legacy code. Eventually, all communication will be done via DBUS and the screenlet will be embedded inside the container using GtkPlugs/Sockets. Dragging a screenlet from the desktop to Awn, Gnome-panel, or Kiba Dock will resize the screenlet and embed it in the dock/panel optionally only showing an icon sized preview.

Due to the way that things are going to be implemented, application developers will be able to wrap parts of their apps inside Screenlets. For example, if you have GIMP running, you’ll be able to pop the ruler screenlet out of GIMP and drag it on to your desktop. When you’re done using it on the desktop, you’ll be able to either dock it in the panel or drag it back into GIMP or even another app like Inkscape.

A few weeks ago I wrote up a post explaining the rationale behind the idea. You can find it here: http://theesylum.com/2008/02/01/desktop-20/. There is also a forum thread on the idea here.Please note that much of the information in the first few posts about implementing the idea is no longer relevant.

The code is on launchpad here. One or two of the old screenlets may not work due to the major changes I’ve made lately. I’m going to push a revision in a few minutes fixing some of them.

Just to clarify, I’m (currently) the only developer working on this and (at this point) the code is independant of the Screenlets project. If anyone is interested in helping out then please email me.


  1. [...] some of you already read this posts, but I wanted to share this idea in our (not yet existing [...]