Working StatusIcon code

uitest.py

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

win = Gtk.Window()
win.connect("delete-event", Gtk.main_quit)
win.show_all()

theme = Gtk.IconTheme.get_default()

_sizes = [16, 22, 24, 32, 48, 128, 'scalable']

for s in reversed(_sizes):
    try:
        px = GdkPixbuf.Pixbuf.new_from_file('data/images/%sx%s/exaile.png' % (s, s))
    except:
        px = GdkPixbuf.Pixbuf.new_from_file('data/images/%s/exaile.svg' % s)

    s = s if s != 'scalable' else -1

    theme.add_builtin_icon('exaile', s, px)

icon = Gtk.StatusIcon()
icon.set_from_icon_name('exaile')
icon.set_tooltip_text("WTF")
icon.set_visible(True)

def later():
    print "Got size", icon.get_size()
    
GLib.timeout_add_seconds(1, later)

Gtk.main()