How to port Python program from gtk2 to gtk3?

Question

We are trying to port this program from gtk2 to gtk3. When I try pygi-convert.sh I got the following error:

Traceback (most recent call last):
  File "scripts/amir", line 53, in <module>
    from gi.repository import GObject
  File "/usr/lib/python2.7/dist-packages/gi/__init__.py", line 39, in <module>
    raise ImportError(_static_binding_error)
ImportError: When using gi.repository you must not import static modules like "gobject". Please change all occurrences of "import gobject" to "from gi.repository import GObject". See: https://bugzilla.gnome.org/show_bug.cgi?id=709183

Any suggestion or other way to do this port?

Well, why not manually change that `import gobject` to `from gi.repository import GObject`? — Aran-Fey, Feb 25 '18 at 13:18
@Aran-Fey Because when I did that, lots of errors occurred, do you have any other idea? — Daniyal Javani, Feb 26 '18 at 05:30
GTK4 is in the works, are you sure you want to do port it now? — gianmt, Feb 26 '18 at 08:16
@Aran-Fey I add a new branch https://github.com/Jooyeshgar/amir/tree/gtk3 and run the pygi-convert.sh and do some fixes but many features not working for now! any idea? — Daniyal Javani, Feb 26 '18 at 09:33
@gianmt: It'll be out in 2019 at best, and GTK+ 4 will still use gobject-instrospection, so porting to GTK+ 3 is not useless. — liberforce, Feb 26 '18 at 09:59

liberforce · Answer 1 · 2018-02-26T11:38:09.160

First, try to understand what you're doing. Read the basics of official Python for GTK+ 3 tutorial. You'll see that the correct order to do imports is:

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

The pygi-convert.sh is no silver bullet, you have to understand the changes and review them. For example the imports in this section are most certainly wrong. The order is not correct, and you still have an import gtk left on the import gtk,Gtk.glade line. A git grep -w gtk should help you find all the lowercase gtk occurences in your code, which should be removed or replaced.

I also see you have in that same file some code to change the window theme. Theming changed completely between GTK+ 2 and GTK+ 3. GTK+ 3 uses a CSS engine.

Check out the Python GTK+ 3 API to know what's available, and check in the C migration guide (not aware of a python resource for that, sorry) what has changed between GTK+ 2 and GTK+ 3. Most things won't apply to python, but some will. For example migrating from the old expose-event to the draw signal when doing custom drawing, or checking which widgets have been killed and replaced.

Then try to run, fix errors, rinse, repeat.

How to port Python program from gtk2 to gtk3?

1 Answers1