GtkIconView - centering content

[Vaidas Mikalauskas <info vaidas name>]

Hi,

I'm working with GtkIconView where all cells are fixed width and I
can't find a way to center them, I have tried the following two
methods:
  - setting "margin" and "column_spacing" properties of GtkIconView;
The problem is that when I set margin - the upper margin also is set
(and I want only horizontal centering);
  - setting margin_left property. This working a bit faster, but
margin is drawed using different color as GtkIconView background (with
Adwaita icon view background is white and margin is drawed grey) - is
this a bug?

any help/suggestions/comments?

-- 
Vaidas