The code previously was using CSS to define row/column spacing and
padding which was combined with a subicon size computed in code relative
to the requested icon size.
In smaller icon sizes it was possible for the CSS spacing+padding + the
size of the two subicons to exceed the requested icon size. This then
would lead to the label being pushed down for app folders compared to
other icons.
Another more severe issue caused by this would happen if the first item
in an icon grid was an app folder. Then the calculation for the maximum
allowed icon size could be off, leading to all icons in the grid
becoming smaller than actually necessary.
This commit changes this to use homogeneous row and column layouts to
evenly distribute the remaining spacing instead of using a fixed CSS
value.
Fixes https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/3069
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1581>
18cd24e6f4