The attribute to set or unset is specified by @attribute. This
can be one of the standard attribute names %G_MENU_ATTRIBUTE_LABEL,
%G_MENU_ATTRIBUTE_ACTION, %G_MENU_ATTRIBUTE_TARGET, or a custom
attribute name.
Attribute names are restricted to lowercase characters, numbers
and '-'. Furthermore, the names must begin with a lowercase character,
must not end with a '-', and must not contain consecutive dashes.
must consist only of lowercase
ASCII characters, digits and '-'.
If @value is non-%NULL then it is used as the new value for the
attribute. If @value is %NULL then the attribute is unset. If
the @value #GVariant is floating, it is consumed.
See also g_menu_item_set_attribute() for a more convenient way to do
the same.
Sets or unsets an attribute on @menu_item.
The attribute to set or unset is specified by @attribute. This can be one of the standard attribute names %G_MENU_ATTRIBUTE_LABEL, %G_MENU_ATTRIBUTE_ACTION, %G_MENU_ATTRIBUTE_TARGET, or a custom attribute name. Attribute names are restricted to lowercase characters, numbers and '-'. Furthermore, the names must begin with a lowercase character, must not end with a '-', and must not contain consecutive dashes.
must consist only of lowercase ASCII characters, digits and '-'.
If @value is non-%NULL then it is used as the new value for the attribute. If @value is %NULL then the attribute is unset. If the @value #GVariant is floating, it is consumed.
See also g_menu_item_set_attribute() for a more convenient way to do the same.