The Evil Blog

Some may have seen that I was pimping my session Rocking out with libunity at the Ubuntu Developer Week promising a surprise. The surprise was that I had a fully working Unity Place implementation all in Python. If you want you can peruse the full log from the IRC session, it might be helpful if you want to try this out yourself.

Hopefully unsurprisingly – the Python integration is all done with PyGI, the Python bindings for GObject Introspection. I must admit that it was a slight challenge getting everything working smoothly, but we’re there now. I want to give mad props to the pygobject- and the GObject Introspection teams. Without their enduring help we wouldn’t have got to this point. So thanks guys, you rock!

So lets get down to business. How does this work, what does it look like?

Setting up a Development Environment

First you need to make sure you have the required development packages installed (you can just click the links to install them if you want):

sudo apt-get install gir1.2-unity-3.0 gir1.2-dee-0.5 gir1.2-dbusmenu-glib-0.4

Now, unfortunately not everything you need is packaged just yet. Namely you may need to install the so called Python overrides for the Dee library. Check if you have this file on your system:

/usr/lib/pymodules/python2.7/gi/overrides/Dee.py

If you don’t have that file it means you’re in in the vicinity of the writing of this blog post, in the time dimension; and thus must install it manually. Here’s how. Download Dee.py and copy it to the right location for PyGI to pick it up:

sudo cp Dee.py /usr/lib/pymodules/python2.7/gi/overrides/

With that in place we’re ready to hack.

Writing a Place in Python

The easiest way to start is to check out lp:~unity-team/unity-place-sample/unity-place-python:

bzr branch lp:~unity-team/unity-place-sample/unity-place-python

And then closely follow the README. If you read through it while having the Unity Places spec and IRC log from the devsession at hand you should have a chance of grokking what’s going on. If you have any problems or questions don’t hesitate to ping me on IRC on the #ayatana channel on FreeNode.

I should also add that we’re working on getting some Python API docs for Dee, Dbusmenu, and libunity out. Watch this space!