GtkTextDirection.
If the text direction is not wildcarded, then the
text direction the icon source applies to should be set
with gtkIconSourceSetDirection, and the icon source
will only be used with that text direction.gtkIconSourceSetDirectionWildcarded(object, setting)objectsettingTRUE to wildcard the text directionGtkIconSet prefers non-wildcarded sources (exact matches) over
wildcarded sources, and will use an exact match when possible.