Help with a GenericCellRenderer using pygtk

I am trying to create a GenericCellRenderer to use for bookmarking items using a custom image of a pin instead of using the standard CellRendererToggle with a checkbox toggle.

Here is the code I wrote till now.

Now my problem is i want to detect if the cell is active or not. For that I want to use the property active and and

I really would like to finish this for a the zeitgeist release! Please Help!