drawing drop shadow for PanelButton

[Olaf Leidinger <oleid mescharet de>]

Dear list,

in my extension, I use a St.DrawingArea [1] as actor of a
PanelMenu.Button. The DrawingArea is used to draw an animation and an
icon. Everything works fine, so far, but I've been told by a theme
author, that no drop shadow is drawn. 

St.Icon has a drop shadow and I dug through it's C source to find out,
how it is done. Yet, I'm wondering, if there is an easier and possibly
more portable way (portable between g-s versions) than porting the C
source to JS.

Is it, maybe, possible to transform the DrawingArea to a GIcon and
use it in a St.Icon? 

As far as I can tell, there is no drop shadow implementation in cairo
and not even a blur function and I'd like to avoid implementing it in
JS.

Best,

Olaf 


[1] https://github.com/oleid/gnome-shell-teatime/blob/master/src/icon.js