Retrieves the gdk.paintable.Paintable used for the icon.
If no gdk.paintable.Paintable was used for the icon, null is returned.
Icon position
A gdk.paintable.Paintable if no icon is set for this position or the icon set is not a gdk.paintable.Paintable.
Retrieves the gdk.paintable.Paintable used for the icon.
If no gdk.paintable.Paintable was used for the icon, null is returned.